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AndyL
14-Jul-2016, 06:32
Newbie question. Getting ready to shoot my first LF 8x10. Using HP5 film. Most likely using Ilford Ilfotec HC developer. Reading about calibrating film and and using a Densitometer. Is this still necessary if I am using the same developer and Film? I don't have a densitometer and my head exploded when I tried to understand the process. I also have access to a 4x5 camera and HP5 film for testing.(cost) Is there a easier way to test? thanks

Randy Moe
14-Jul-2016, 06:50
You are new here. Good question and by asking you trigger the automatic site search for similar results.

They are listed at the bottom of this page.

Shoot some 4x5 first...

bob carnie
14-Jul-2016, 07:09
Kodak had a nice tip for evaluating your negatives.

Place your negative over top of a newspaper. If you can just read the type through the highlight area, and there is detail in you shadow area you pretty much have a good negative.

After 40 years of printing for others I still find this to be good advice.

Bob

Peter De Smidt
14-Jul-2016, 07:57
If you have access to a densitometer, then it's really not that hard to simple exposure/development tests. Fred Picker's Zone VI Workshop, probably available at your local library, lays out a good method, although he works in 1/2 stops, while I prefer 1/3 stops, as that mirrors available film speeds.

It's important to know that exposure has the greatest effect on darker areas of your scene. If you don't give enough exposure, they won't have any detail. Conversely, development time/temp/agitation affects the brighter areas of your scene more than the darker ones. As a result, you want to give your film enough exposure to get detail in your scenes darker areas, and you want to develop such that you have good tonal separation in your negative, and that the highest densities are appropriate for the medium you're going to print with. For instance, many alternative processes need more negative density than does printing on silver gelatin paper.

Assuming you're going to be taking landscape photos, and have a spot meter, do the following. Load some film holders. Set up a black mat card in shade, as you're gong to test film speed first. A standard black poster board works well. Meter the card, making sure that it is evenly lit. Make sure that there is nothing too bright in the background of the photo. Focus your camera on infinity, and aim it so that the card is in the center of the frame. You focus on infinity so that bellows extension doesn't affect the results. It doesn't matter that the card will be a little fuzzy. Set your meter reading for box speed, i.e. set it at ISO 100 for a 100 speed film. Measure the card. Let's say it gives f/8 at 1/60th of a second. Exposing at that setting would give a middle gray, known as Zone V in Zone System parlance. In this case, though, we're looking for Zone I, the lowest amount of light that'll still record well on the negative. To place the card on Zone I, you have to close down the aperture 4 stops, give 4 stops less exposure time, or a mixture. I prefer to work in aperture stops. Thus if the card reads f/8 at 1/60th with the meter, you'd set f/32 at 1/60th on your lens, placing the card on Zone I. Expose your negative. Now expose a couple more negatives opening the aperture by 1/3 stop each time.

Develop the film according to your best guess at the proper development. Read the film base + fog, the unexposed area of the film. Now read the densities of the card for each of the negatives. The negative shot at box speed will have the least density. You're looking for the negative that gives a Zone I density of at least .1 above film base plus fog. (That's traditional zone system practice. I prefer 0.15.) If the card shot with your first negative gives the proper density, then your film speed is what the manufacture says. Congratulations! That's not all that common. Usually the true film speed is about 1/2 of the advertised one. But if the desity is to low, move to the next negative, which should be slightly more dense. Since you gave 1/3 stop more exposure, this negative represents rating your film 1/3 stop slower than box speed. (So if box speed is 100, this negative would represent 80.) Keep reading negatives until you get the proper speed. Each one represent your film being 1/3 stop slower than the one before it.

Now you know your normal film speed. The next step is to fine tune your development time.

Set up a matte white card in sun. Meter the card. You want to place it on Zone VIII, a bright area with detail. Focus on infinity and take a meter reading, using the ISO setting that you determined in the earlier test. Setting the shutter at that setting would give a middle gray, Zone V. To get to Zone VIII, open up 3 stops from the meter reading. Expose 3 negatives at that setting. Now develop the sheet of film. If you're printing with a diffusion enlarger onto silver gelatin paper, you want a Zone VIII density to be about 1.3 above film base plus fog. If the negative density is to low, try developing another sheet for 20% more time. If the negative density is too high, develop for 20% less time. Use more sheets of film to narrow it down, if needed. After awhile, you'll get pretty good at guessing the proper development time from using one sheet of film.

You now have your Normal (N) film speed and development time.

Ken Lee
14-Jul-2016, 08:02
I don't have a densitometer and my head exploded when I tried to understand the process.

Me too. You might find this article helpful: Testing B&W Film (http://www.kennethleegallery.com/html/tech/testing.php)

Note that "almost everyone" who does rigorous film testing ends up shooting at one f/stop slower than box speed: 200 for HP5+ and TMY, 50 for FP4+ and TMX, etc. The more important issue is determining the development times which work for you.

If you don't care to load the Zone System into your brain, you might also find this even more helpful: A Simpler Approach (http://www.kennethleegallery.com/html/tech/index.php#simpler). It's what I use after many decades.

Michael R
14-Jul-2016, 08:07
Note that "almost everyone" who does rigorous film testing ends up shooting at one f/stop slower than box speed: 200 for HP5+ and TMY, 50 for FP4+ and TMX, etc.


And there is a simple reason for that, which almost nobody wants to know about, unfortunately. Suffice it to say if you plan on finding an EI using a Zone System-type test, you can skip that part and simply reduce film speed by 2/3 stop (or round it to either 1/2 stop of 1 stop).

Randy Moe
14-Jul-2016, 08:11
And there is a very simple reason for that, which almost nobody wants to know about, unfortunately. Suffice it to say if you plan on finding an EI using a Zone System-type test, you can skip that part and simply reduce film speed by 2/3 stop (or round it to either 1/2 stop of 1 stop).

Well we are curious now. Do tell!

I simply go by the rule to overexpose film and underexpose digital.

Peter De Smidt
14-Jul-2016, 08:16
And there is a simple reason for that, which almost nobody wants to know about, unfortunately. Suffice it to say if you plan on finding an EI using a Zone System-type test, you can skip that part and simply reduce film speed by 2/3 stop (or round it to either 1/2 stop of 1 stop).

Often that works, but with TMY in my system it doesn't. My EI using Zone System testing is 500.

Ken Lee
14-Jul-2016, 08:24
Correct me please if I am wrong, but one reason (according to Phil Davis) is that a standard gray card is not middle gray or Zone V under typical lighting conditions. See The Myth of the 18% Gray Card (http://www.kennethleegallery.com/html/tech/index.php#myth)

Michael R
14-Jul-2016, 08:41
Randy:

The Zone System speed point is based on the pre-1960 ANSI/ISO standard that included an extra 2/3 stop "safety factor". The safety factor in the standard at that time was larger because historically meters, shutters etc. were less precise. The safety factor was then revised downward by 2/3 stop to account for improvements in equipment, and the increased popularity of smaller film formats. The Zone System was never updated. It is important to note the safety factor is just that. It is not, in and of itself, based on print quality.

Since the Zone System speed point includes the larger safety factor than current ISO ("box" speed), all you're doing when you do a Zone System EI test, is confirming the difference in the safety factor. This is important, because it means most people actually misunderstand the Zone System EI test, and therefore misinterpret the results. When you do a Zone System EI test, you're not actually revealing new information. You're not finding a "better" speed in terms of tone reproduction quality, you're not finding a "truer" speed, and also importantly, you're not finding a speed based on your own working methods (which most Zone System books would have us believe).

There's some more theory on this, and flare is important too, but I'll stop there pending attacks (that's usually what happens).

All this to say, barring extreme procedures and special purpose developers, 9 times out of 10 people will find personal ZS EIs in the range of 1/2 to 1 stop slower than ISO speed. Now you know why.

Peter's example is good to show there can be exceptions, although his case does seem odd to me. When I ran ZS tests on TMY-2 I got exactly what the theory predicts.

Peter De Smidt
14-Jul-2016, 08:43
Or it might have to do with the development system used by the ISO standard, but maybe that should be a different thread?

For the original poster, the options seem to be.

1. Guess and revise. Shoot some picture rating the film at 1/2 box speed. Develop and print your negative (or scan....) Do you have enough shadow detail? Does the tonality look right? If not, adjust.
2. If you have an incident meter. You can do Phil Davis's "Beyond the Zone System" tests, or Ken's simplified system. Doesn't the View Camera Store offer BTZS testing?
3. If you have a spot meter, and access to a densitometer, you can do traditional zone system testing.
4. ?

A good current book on all of this is Way Beyond Monochrome, 2nd Edition by Ralph Lambrecht and Chris Woodhouse.

Randy Moe
14-Jul-2016, 08:54
Randy:

The Zone System speed point is based on the pre-1960 ANSI/ISO standard that included an extra 2/3 stop "safety factor". The safety factor in the standard at that time was larger because historically meters, shutters etc. were less precise. The safety factor was then revised downward by 2/3 stop to account for improvements in equipment, and the increased popularity of smaller film formats. The Zone System was never updated. It is important to note the safety factor is just that. It is not, in and of itself, based on an improvement in print quality.

Since the Zone System speed point includes the larger safety factor than current ISO ("box" speed), all you're doing when you do a Zone System EI test, is confirming the difference in the safety factor. This is important, because it means most people actually misunderstand the Zone System EI test, and therefore misinterpret the results. When you do a Zone System EI tests, you're not actually revealing new information. You're not finding a "better" speed in terms of tone reproduction quality, you're not finding a "truer" speed, and also importantly, you're not finding a speed based on your own equipment and working methods (which most Zone System books would have us believe).

There's some more theory on this, and flare is important too, but I'll stop there pending attacks (that's usually what happens).

All this to say, barring extreme procedures and special purpose developers, 9 times out of 10 people will find personal ZS EIs in the range of 1/2 to 1 stop slower than ISO speed. Now you know why.

Peter's example is good to show there can be exceptions, although his case does seem odd to me. When I ran ZS tests on TMY-2 I found I got exactly what the theory predicts.

Thanks for the reply. I see your point and a major reason I don't use Zone is the whole added personalization to a lens, aperture, and shutter error combo. i play with too many combos to do that. I do test my shutter speeds, but don't fix shutters, simply adjust to actual and I am often using flash, so...

All good!

Ken Lee
14-Jul-2016, 08:58
When you do a Zone System EI tests, you're not actually revealing new information. You're not finding a "better" speed in terms of tone reproduction quality, you're not finding a "truer" speed, and also importantly, you're not finding a speed based on your own equipment and working methods (which most Zone System books would have us believe)....

All this to say, barring extreme procedures and special purpose developers, 9 times out of 10 people will find personal ZS EIs in the range of 1/2 to 1 stop slower than ISO speed. Now you know why.

Peter's example is good to show there can be exceptions, although his case does seem odd to me. When I ran ZS tests on TMY-2 I found I got exactly what the theory predicts.

Amen

By way of confirmation: when I purchased the BTZS Plotter program I was stunned to see that for every given film tested, every developer tested could deliver the same basic effective film speed and contrast curves. The only real variations were the dilutions and times required to reach them. The most differences I recall amounted to no more than 1/2 f/stop, more like 1/3 of a stop: well within the margin of error in the field.

Eventually, I found it all reassuring and felt safe to pay more attention to aesthetics.

Peter De Smidt
14-Jul-2016, 09:03
Peter's example is good to show there can be exceptions, although his case does seem odd to me. When I ran ZS tests on TMY-2 I got exactly what the theory predicts.

It surprised me, too, although I was using Xtol, which is supposed to give a small speed bump. I ran the tests two more times, and I now have a couple of years of use under my belt. It works for me. Here are the results in my system for other films: Acros (80), Delta 100 (64), HP5+ (200), Tri-x (250).

TMY @ EI 500:

https://www.dropbox.com/s/8g3zgi26w5r1ra6/Girls_Rialto_Arch.jpg?raw=1

Michael R
14-Jul-2016, 09:03
Or it might have to do with the development system used by the ISO standard, but maybe that should be a different thread?



Possible, but unlikely. The ISO standard doesn't specify a developer formula. I typically use XTOL and D-76 for this sort of thing.

Factoring in the 2/3 stop measurement difference combined with the fact you're targeting a higher density than 0.1, I'd have expected an EI more than a stop below ISO, and yet you're at 500. Can't argue with whatever works though.

And in the end, in the field a working EI depends mostly on how we meter. But ZS tests (or other similar tests) don't factor that in .

Bill Burk
14-Jul-2016, 09:55
This is the easiest way I can recommend: Take half the rated speed as a given (you are using fresh standard film and standard developer so this is trustworthy - people shooting X-Ray film or homemade emulsions have to do speed tests).

Now go out and shoot something, anything at all using that speed.

Pretend you are bracketing but this is special. Expose a second sheet with exposure increased by 2 f/stops.

Develop both sheets the same.

Print the thinner negative to your satisfaction. Mark the back of the print in pencil so you know it's the first one.

Double the time on your exposure timer and print and develop from the denser negative.

If you can't tell the prints apart, then your film development time is correct.

Randy Moe
14-Jul-2016, 10:03
This is the easiest way I can recommend: Take half the rated speed as a given (you are using fresh standard film and standard developer so this is trustworthy - people shooting X-Ray film or homemade emulsions have to do speed tests).

Now go out and shoot something, anything at all using that speed.

Pretend you are bracketing but this is special. Expose a second sheet with exposure increased by 2 f/stops.

Develop both sheets the same.

Print the thinner negative to your satisfaction. Mark the back of the print in pencil so you know it's the first one.

Double the time on your exposure timer and print and develop from the denser negative.

If you can't tell the prints apart, then your film development time is correct.

I like that and will try it with HP5 actual contact prints, not scans.

Then I am off to X-Ray Land. :)

Drew Wiley
14-Jul-2016, 10:34
No need to get complicated and buy a densitometer. Besides, unless you understand the basics of film first, you're not going to understand film plotting either, using a densitometer. First, for any given film and developer combination you need to establish your threshold shadow value. Bracket a series of exposures starting
at about half "box speed". Look at your developed negative below a task lamp against a deep black background, holding it under the light. Often you can see a
reflected POSITIVE image which reveals how much shadow detail you've really got. ... Another simple trick is to make your own "visual densitometer". Buy a
calibrated step wedge, then take two pieces of black cardboard and punch a little hole in the middle of each. Put these side by side on the same light box.
Slide around your negative under one hole, you step wedge under the other, to find which step density matches. The human eye is surprisingly good at comparing density under such circumstances. Good enough, at least, for getting started in black and white work if you need to measure density at all.

Randy Moe
14-Jul-2016, 10:45
No need to get complicated and buy a densitometer. Besides, unless you understand the basics of film first, you're not going to understand film plotting either, using a densitometer. First, for any given film and developer combination you need to establish your threshold shadow value. Bracket a series of exposures starting
at about half "box speed". Look at your developed negative below a task lamp against a deep black background, holding it under the light. Often you can see a
reflected POSITIVE image which reveals how much shadow detail you've really got. ... Another simple trick is to make your own "visual densitometer". Buy a
calibrated step wedge, then take two pieces of black cardboard and punch a little hole in the middle of each. Put these side by side on the same light box.
Slide around your negative under one hole, you step wedge under the other, to find which step density matches. The human eye is surprisingly good at comparing density under such circumstances. Good enough, at least, for getting started in black and white work if you need to measure density at all.

Drew, i like your idea of "visual densitometer" which has been something I want. I used to compare metal surface RA (roughness) with a stainless steel plate my factory used to sell to machinist. It had a variety of values to compare.

I find step wedges pretty expensive and some won't sell without buying the whole shebang.

Then I read a kidding? comment here about Stouffer running out of Tech Pan. Bingo!

What's a good plan to DIY a 35 mm film strip step wedge with my Nikon F5 which seems to expose everything perfectly?

I would appreciate any ideas. Thanks!

Michael R
14-Jul-2016, 11:17
DIY-ing a sensitometric wedge would be very difficult, time consuming, and require more $$ in film than it costs to buy a wedge from Stouffer ($7.50 - you don't need a calibrated wedge). For a DIY, you'd need a film/developer combo that is perfectly linear over a long density range, a gamma of 1.0, and a way to evaluate that, so the problem becomes somewhat circular. You have to start with something known, so you'd need a densitometer to make the DIY step wedge.

The best way to "calibrate" a system (and the way it should ultimately be done even if you do have a densitometer) is to make test prints. Negatives and paper are a system. Densitometry/target density ranges should only be considered starting points. One can easily end up with surprises in printing, after calibrating negatives to specific density ranges as measured with a densitometer.

Regarding ZS-type calibrations, also realize the negative density range you have on the test negatives is not necessarily the density range you end up with in the field due to flare, which changes where shadow placements fall on the curve.

(by the way Stouffer doesn't use Tech Pan).

Doremus Scudder
14-Jul-2016, 11:52
@ OP,

Michael is the guy to follow here. Forget the film testing, just rate your film a bit slower than box speed for more of a safety factor. (FWIW, my ZS E.I. tests usually come out 1/3 stop slower than box speed.)

The important thing is to nail down development times. But you don't really need a densitometer for this either.

If you're printing traditionally, then find a scene with a wide range of tones in well-separated areas that fulfills the criteria of "Normal." Make several shots, keeping careful notes about your metering; where you place the shadow value and where all the other values fall. Then develop a negative at your starting development time and print it on the paper you intend to use most at an intermediate contrast grade (2-3). When printing, match the shadow value to where you placed it when shooting (yes, this is subjective, but how we meter and place is an important factor here). Make a straight print at this exposure, dry it down and sit down with your print and the metering notes. If things match up well, then you've come very close to an ideal "N" developing time. If the high values are too hot, reduce the development time by 20% and try again; the reverse if the highlights are too dark, reduce the time by 20%.

Make a print from the second negative in exactly the same way and evaluate it. At this point, you should have a handle on on or two development schemes (N, N+1 or N-1). Interpolate an intermediate time if needed and go out and shoot. Keep good metering notes and you'll be able to tweak your development times as needed when things go a little one way or the other.

That's really all you need. Keep in mind that you just have to get the neg somewhere in the middle of the available contrasts of paper you have available. Then you use paper grade changes, etc. to refine when printing.

Best,

Doremus

Drew Wiley
14-Jul-2016, 12:29
You pay a bit more for a CALIBRATED step wedge (with a an attached ledger showing the factory-measured densities of each step), but they can be typically had for around $30 new from graphics suppliers or some darkroom suppliers. And I would personally recommend a calibrated one if you are going to attempt visual densitometry, or even later on double-check the accuracy of an electronic densitometer. Don't buy old used wedges. They could be stained from handling, and have often yellowed, making evaluation of fbf density a headache. And no sense making your own. Special films were used for this in the past: either Eastman Color Separation Film or Super-XX due to their extremely long straight characteristic curves. I don't know what they substitute nowadays; but it's probably TMX100, which would certainly be the most logical candidate. Tech Pan would be worthless for this kind of application.

Neal Chaves
14-Jul-2016, 18:27
I started years ago with Tri-X and HC110B (1:31 at 68*), then switched to HP5+ in HC110B. Now changing over to HP5+ in Ilfotech HC (1:31 at 68*) because no suppliers will ship HC110.
Try this. It should put you in the "normal" ballpark at full emulsion speed with the first sheet. I develop HP5+ 8X10 rated at 400 EI one sheet at a time in an 8X10 tray in Ilfotech HC 1:31 at 68* for 7:30. I immerse the sheet directly into the developer and agitate for the first thirty seconds, then five seconds each following thirty seconds.

Ilford's data suggests 6:30. If you do that and rate at 200EI you will also produce a nice "normal" negative with slightly increased highlight and shadow detail and slightly reduced grain size. If you rate at 100EI and develop for 5:00 and you can tolerate the loss in film speed, you will be quite pleased.

AndyL
15-Jul-2016, 05:59
WOW, Thanks to all of you for commenting. I think I learned more in a day reading these posts. I will follow your combined advice and report back when my testing is done. Thanks

Luis-F-S
15-Jul-2016, 08:20
If you have access to a densitometer, then it's really not that hard to simple exposure/development tests. Fred Picker's Zone VI Workshop, probably available at your local library, lays out a good method, although he works in 1/2 stops, while I prefer 1/3 stops, as that mirrors available film speeds.

You're looking for the negative that gives a Zone I density of at least .1 above film base plus fog. (That's traditional zone system practice. I prefer 0.15.)

Now you know your normal film speed. The next step is to fine tune your development time.

You now have your Normal (N) film speed and development time.

Peter speaks the TRUTH! Using a light meter as a densitometer or a "visual densitometer" is a bunch of baloney. Fred Picker tried to come up with an intuitive method for most photographers (who are to lazy to do it right) and he offered to read negatives with a densitometer and return them with values. You can buy the Zone VI workshop used for $3.99 shipped. That's less than the cost of a single sheet of 8x10 film. But you do have to get off your computer and read it!

With 8x10 cost north of $5/sheet, you can waste all the film you can afford with your light meter or visual densitometer, but all you'll have is a bunch of wasted film or bad information which is worse than no information.

I follow Oliver Gagliani's methodology that he taught in his workshops in which he shot a "daylight" bulb behind a sheet of plexiglass. The front was masked with black paper, so you only had a bright circle in the center of even ilumination. You took a light reading of that area, set your shutter speed and aperture and then used ND filters to decrease the light instead of stopping the lens down as that is much more accurate. Then choose the ASA and developing time for a Zone I expose which was 0.15 density units over film base plus fog. That nailed your film speed and developing time.

Oliver was a pupil of Minor White and Ansel Adams and he attended the California School of fine Arts in the 1940's. He took up photography after loosing some of his hearing in the "big war" so he could no longer play the violin. After seeing a Paul Strand show, he was so impressed that he decided to become a photographer. I am fortunate to have several of Oliver's prints which I can always use as a frame of reference.

It's photographic sensitometry (aka science). Any other "easier systems" or short cuts are going to be flawed. It's just a matter of how good a negative you want to make, and how easily it will print. If you don't care, or you want to guess at it, go ahead. I'm sure the same "experts" who can't produce a printable negative will have all sorts of convoluted "techniques" to print them.

The last two X-Rite 301 densitometers sold on the 'bay for well under $200.00. That's two boxes of 8x10 Tri-X. You can run your tests using 4x5 film as long as the unexposed film base has the same density and fog, or you can cut down 8x10 sheets to make it last longer.

If someone wants to send me up to 5 LF negatives with a self addressed stamped envelope, I'll read them on an X-Rite 301 and return them. You can PM me for the address. I'll do this as long as it doesn't get out of hand.........

L

Randy Moe
15-Jul-2016, 08:41
Olives's plan is pretty much what I will try to do today.

Test with DSLR for up to 10 stops in 1/2 steps with a known quantity studio strobe and diffusion.

I can then check density results in PS.

The strobe steps down very precisely, I check it all the time.

I made Pictorico step wedges with PS until I threw out the damned printer.

Luis-F-S
15-Jul-2016, 08:46
I rather doubt that Oliver used PS.

Randy Moe
15-Jul-2016, 09:31
I rather doubt that Oliver used PS.

:)!

I am simply checking my light at the moment, then back to film.

Jerry Bodine
15-Jul-2016, 09:49
...You can run your tests using 4x5 film as long as the unexposed film base has the same density and fog, or you can cut down 8x10 sheets to make it last longer....

Luis, here's an fyi that I think is appropriate here. Years ago I queried Ilford about whether it's technically sensible to do film tests using 4x5 sheets and apply the results to larger sizes; here's an edited version of their response:

… all sizes of sheet film are cut out of the same master rolls, so the different formats you mention will have identical characteristics. … There can be small differences between 35mm, 120 and sheet film as these do use different bases and slightly different emulsions. …We endeavor to manufacture all three types to be as close as possible in order for development times to be consistent across the range for any one film type (and they are for most practical purposes).

Bottom line you will not need to duplicate your tests for 5x7 and 8x10.

Luis-F-S
15-Jul-2016, 10:08
As long as the film age and storage conditions are similar, otherwise the fb+f will be different. My 20 YO Tri-X which has been frozen, has a fb+f 3 x that of new film.

Bill Burk
15-Jul-2016, 11:18
While there is nothing quite as informative as a 5 sheets of sensitometrically-exposed film developed for different times and graphed, which provides information for a wide variety of exposure and development planning...

The two shot plan deserves review. It takes advantage of a few reasonable assumptions and quickly reaches a commonly-accepted normal exposure and development. I particularly like the fact it wastes no film. (The second shot is likely to be a good alternate take). And it wastes (maybe) only one sheet of paper.

If you did a test strip for the first print in f/stop series, that first test strip can provide additional information when compared to the second print (because second print will match one of the steps of the test strip).

Assumptions: Fresh film has trustworthy characteristics, Zone System metering is keyed to 2/3 stop below ISO speed (thus 1/3 stop safety factor with Zone System), 1 stop safety factor if using a standard metering technique which uses ISO speed (which is beneficial for black and white negative work), 0.50 gradient is a reasonable normal gradient, two measured points would probably be on the straight line and would reasonably give an approximate average gradient.

This is a lot of explanation for a simple test where you take two shots two f/stops apart and make two prints from the negatives.

Kevin J. Kolosky
15-Jul-2016, 13:03
If you want it tested send it to me and I will read it with my densitometer.

Drew Wiley
15-Jul-2016, 15:34
Thousands and thousands of dye transfer prints were made from color separation negatives using visual densitometry before what we currently call densitometers ever existed. Kodak even marketed a self-contained version of a visual densitometer with a rotating step wedge. You might find a picture of one of these devices somewhere. Maybe a few still exist. Sure, I prefer to use a modern X-Rite transmission densitometer. But unless you are doing diagnostic work, a trained unfatigued eye can compare density dots remarkably accuratelym certainly well enough for basic film testing. But ordinary light meters aren't of much use for this.

Neal Chaves
15-Jul-2016, 19:33
I have been using a Cibachrome Exposure Monitor M-3 for years as a desitometer. It works very well and they can be bought for a few dollars today.

Peter De Smidt
15-Jul-2016, 22:15
Sure, you can get along just fine without a densitometer, but they can be gotten super cheap if you look, at least they could a few years ago. (I gave away a not-so-old X-rite color densitometer not that long ago.) Or perhaps you know someone with one..... They do make some things very fast and easy, especially for someone who doesn't have a good sense of what a good negative should look like.

Bill Burk
15-Jul-2016, 22:42
duplicate post

Bill Burk
15-Jul-2016, 22:43
Thousands and thousands of dye transfer prints were made from color separation negatives using visual densitometry before what we currently call densitometers ever existed. Kodak even marketed a self-contained version of a visual densitometer with a rotating step wedge. You might find a picture of one of these devices somewhere. Maybe a few still exist. Sure, I prefer to use a modern X-Rite transmission densitometer. But unless you are doing diagnostic work, a trained unfatigued eye can compare density dots remarkably accuratelym certainly well enough for basic film testing. But ordinary light meters aren't of much use for this.

152911

This is what my Marshall Studios Densitometer looks like on the inside. It's a diffuse visual densitometer, based on the law of inverse squares. Light bulb moves back and forth and when the bulb is closest to the eye it's going through a 3.00 density sample... while the light from the other side of the bulb has to travel about 30 inches to reach the eye. With the bulb at the far side, light has to travel about the same distance to the eye which is 0.00 density. It reads in resolution of 0.01 when you read between the lines. I picked this up because I was a little nervous about having to rely on the old electronics of my Macbeth TR524 (The Macbeth still works fine, but for a possible future "City of Ember" dystopia... I'd rather have the Marshall which relies on primary principles).

Bill Burk
16-Jul-2016, 19:48
And there is a simple reason for that, which almost nobody wants to know about, unfortunately. Suffice it to say if you plan on finding an EI using a Zone System-type test, you can skip that part and simply reduce film speed by 2/3 stop (or round it to either 1/2 stop of 1 stop).

Randy Moe,

In case you are still curious it's really quite plain:

The ISO metered exposure is ten times the exposure of the speed point. Those familiar with the way we use logarithms to represent exposure in photography will recognize that the idea "ten times the exposure" can be represented as 1.0

When you do Zone System testing you close down four stops as you go from Zone V to Zone I. So with one f/stop being 0.3 ... four f/stops is 1.2

The difference between the two methods is the difference between 1.2 and 1.0 ... 0.2

That is 2/3 of a stop. That's where the 2/3 stop difference comes in... the difference between Zone System and ISO.

It is also true that you develop a little less for Zone System Normal than you do for ISO testing. That might show up in Zone System tests as an additional 1/3 stop of speed loss.

Simple, isn't it?

Randy Moe
16-Jul-2016, 21:02
Bill Burk,

I am reading it all while packing for a morning shoot.

That said, I feel I'm on the right side of the Bell Curve...

Ok read that 5 times Bill to finally get it.

Thanks!

neil poulsen
16-Jul-2016, 23:35
. . . Reading about calibrating film and and using a Densitometer. Is this still necessary if I am using the same developer and Film? . . .

When it comes to black and white calibrations, one might divide the methodologies fall into three categories:

I.] Those that involve the logical use of a densitometer.

II.] Those that don't involve a densitometer, but can yield reasonable results.

III.] Hocus Pocus. (a.k.a. Hopeless Pocas.)

The book, The New Zone System Manual (White, Zakia, Lorenz; 1976) provides methodologies that fall into the first two categories and does not include methodologies that fall into the third category. So, I would say that this book is a very good starting point.

At least, it's where I started, and after spending quite a bit of time in Category II.], I finally purchased a densitometer. I think that it's common sense that, I obtained more consistent, predictable results by using a densitomter, to the extent that I now consider using one to be absolutely essential. It involved quite a bit of study, enough to make one's head swim. But for me, it was worth it. After having conducting B&W calibrations many times, it's become much more logical and straight-forward.

Randy Moe
17-Jul-2016, 04:55
I: If an ancient gismo is really necessary then we need to examine, review and revive a few. They all look like old electronic garbage to me.

II: This requires methodology of usage clearly? delineated.

III: One reason I am stubbornly resisting buying a magic box is I shot 35mm for 4 decades without meters and still have those Chromes. They are exposed very well.

IV: This section is left blank. Unexposed.

Bill Burk
17-Jul-2016, 09:25
I: If an ancient gismo is really necessary then we need to examine, review and revive a few. They all look like old electronic garbage to me.

You can't go wrong if you can get a couple cheaply and you are handy with fixing gadgets. You are bound to find one that works "just fine as-is" or is easy to fix.


II: This requires methodology of usage clearly? delineated.

This is where you will find many teachers have proposed different but similar methods. It's always interesting to dream up a new experiment for testing. But when it comes to performing the tests, you just have to pick one teacher and follow that method from one end to the other. You may run through a lot of film and paper, but although I might criticize a method for being wasteful of material or time... In the end what I feel is the most important result... is the understanding that you get from a real experience. The different test methods all give you that.


III: One reason I am stubbornly resisting buying a magic box is I shot 35mm for 4 decades without meters and still have those Chromes. They are exposed very well.

Chromes (and to a certain extent Motion Pictures) are a different animal. But even I have a body of 35mm black and white negatives from 35 years ago where I didn't do any of this testing. They are fine. But I was always interested in trying the Zone System one day, and when I finally got into it I found that it was fun.


IV: This section is left blank. Unexposed.

[This page intentionally left blank]

Randy Moe
17-Jul-2016, 10:05
There are 3 very different Dense Meters discussed in this short thread. With no real info to a novice revealed.

I suppose the most expensive is the choice.:)

I am very handy at DIY and repairing most things.

Bill, I am thinking about this, first I need to survive a 1500% property tax increase.

So I am delaying all new expenditures.

Peter De Smidt
17-Jul-2016, 10:40
Randy, you can always borrow my X-rite....

What is it about your current results that you'd like a densitometer to improve on? They're very good for doing developer and film comparisons, figuring out things like reciprocity failure, filter factors.... but as others have pointed out, you don't need one to get great results.

Doesn't Way Beyond Monochrome have a procedure for using a step tablet? It starts with figuring out your real paper grade, and then you can work back to find the negative densities that work best for your system.

If you get a step wedge, I can calibrate it for you.

Randy Moe
17-Jul-2016, 12:42
Randy, you can always borrow my X-rite....

What is it about your current results that you'd like a densitometer to improve on? They're very good for doing developer and film comparisons, figuring out things like reciprocity failure, filter factors.... but as others have pointed out, you don't need one to get great results.

Doesn't Way Beyond Monochrome have a procedure for using a step tablet? It starts with figuring out your real paper grade, and then you can work back to find the negative densities that work best for your system.

If you get a step wedge, I can calibrate it for you.

Ok, Thank you Peter.

But I need to wait a couple months. Money is tight. Stouffer has a $20 plus shipping minimum. I consider that a lot for a piece of graduated acetate. I do want one and will get one in the Fall.

But which one? They offer a lot of choices. I try to buy right.

I think I want one to 'project' in my 6X9 to 8X10 enlargers for printing film negs on SG. And I want one for Alt prints done by contact. I also think it would be good to scan it, shoot it with film and digital on a light box.

You all know I want it all. :)

So suggestions on which one? Somewhere near $20-$30 to meet the minumum price from, http://www.stouffer.net/Productlist.htm

Obviously this is not life and death.

Thanks everybody.

Peter De Smidt
17-Jul-2016, 14:53
I use a TP4x5-31. You can borrow that, as well. The last time I used it was for a scanner test a couple of years ago.

Randy Moe
17-Jul-2016, 15:00
I use a TP4x5-31. You can borrow that, as well. The last time I used it was for a scanner test a couple of years ago.

Sounds good. That wasn't cheap. And it's a good size.

I'm going to study up in Way Beyond Monochrome.

Thanks Peter.

Michael R
18-Jul-2016, 05:37
Randy, don't you need to define what you want to determine first? Are you trying to compare films/processes? Are you trying to get an EI? Are you trying to find your target for normal contrast? Etc. Clarifying these things can help get you to the right "test".

Randy Moe
18-Jul-2016, 06:09
Yes. But I am 65 and playing catchup. I am trying to learn as much as possible. Retain enough to use that knowledge for the bad years I anticipate.

So I have a lot to do. LF gets me out of bed.

Gotta have goals. :)



Randy, don't you need to define what you want to determine first? Are you trying to compare films/processes? Are you trying to get an EI? Are you trying to find your target for normal contrast? Etc. Clarifying these things can help get you to the right "test".

Neal Chaves
18-Jul-2016, 15:13
Here's a Kodak Projection Print Scale which I calibrated with the Zone densities and my Cibachrome Exposure Monitor showing the calculator dial on the bottom. These two vintage darkroom items are very useful and inexpensive.153016153017153018

Randy Moe
18-Jul-2016, 15:28
Very helpful Neil. I use that Projection Scale every print. I do see that meter is cheaper than most Stouffer wedge. I will get one.

Thanks for the show and tell. :)



Here's a Kodak Projection Print Scale which I calibrated with the Zone densities and my Cibachrome Exposure Monitor showing the calculator dial on the bottom. These two vintage darkroom items are very useful and inexpensive.153016153017153018

Drew Wiley
18-Jul-2016, 15:57
Just be wary of those projection scales if they're yellowed. But heck, overall, I've used my real densitometer a great deal, but don't think I used it even once to
master the Zone System itself.

Neal Chaves
18-Jul-2016, 18:51
The "Zone System" being inherently imperfect cannot be mastered. The most you can hope to attain is a good negative from which you can make a satisfying print.

Randy Moe
18-Jul-2016, 19:31
The "Zone System" being inherently imperfect cannot be mastered. The most you can hope to attain is a good negative from which you can make a satisfying print.

I was just cogitating on that.

Everybody seems to meter at least two Zones.

But any film exposure is one event, a measurable bit of light is admitted into the chamber by duration/shutter and aperture/area. Of course we also have 'apparent' aperture from the distance or bellows factor.

Angle of view/light becomes less as the film target recedes.

But like you say Neil, we gotta pick one exposure event and be happy. Or not.

A noticed a troubling forum post the other from an esteemed member who postulated bigger film needs more light...

Not

Pere Casals
19-Jul-2016, 05:51
I don't have a densitometer


If you have a flatbed scanner you have Hi-Performance densitometer, for HP5 you need to measure until 3D, this Density 3 (logarithm, see https://en.wikipedia.org/wiki/Densitometry), a Epson V500 can do it. For Velvia you need to measure until 3.8D so you need something like a Epson V700, 750, 800, 850.

http://www.mrecord.talktalk.net/density_measurement/index.html or Google: using scanner as densitometer

> to convert a scanner to a densitometer disable gamma, corrections, etc, you can use calibrated targets to match...



Is this still necessary if I am using the same developer and Film?

For some BW Kodak sheets datasheet states different developing times, also agitation routine may be different.

Sheets and rolls are not made in the same process, as base is thicker with sheets, something may vary.

I'd recommend you to adjust your process with 135 film, then at the beginning when you shot an HP5 sheet 4x5 also have an SLR loaded with HP5 and make a bracketing of say some 3 different exposures, the same exposure than with 4x5 and +/-1 for example, you will know if it is matching, and if it was better a different exposure for the development you do.

Also consider that LF bellows extention needs a correction on exposure, not if you focus at infinite...

Be careful one thing is the geometric aperture (f/4 5.6 , etc) and another one the transmitance that can be affected by the number of glass groups in the lens and their coating. A zoom has a lot of groups and less light pass, it is compensated by TTL reading, a prime fixed focal SLR lens will work mostly like a LF lens in what exposure matters, but if you have a zoom in the SLR the reading can be 1/2 stop different than with a fixed focal lens. Keep it in mind if you use a SLR/DSLR as photometer.


Anyway as you advance with sheets you will discover that it is good to make an special development for each scene. This is the classic "zone system" and its variants, and much other ways to do things.

This is my 2nd 8x10, with HP5+, if you read the comment you'll see how an special development can be planned for a given scene

https://www.flickr.com/photos/125592977@N05/24852468435/in/dateposted-public/

Regards, and enjoy !!!

Pere Casals
19-Jul-2016, 06:24
I was just cogitating on that.


Me also. : )

I found zone system extremly useful to understand the basics, and to do 90% of the most it can be done.

Then there is the Beyond The Zone System book that explains the same and more.

https://www.amazon.com/Beyond-Zone-System-Phil-Davis/dp/0240803434

I think that this is math on densities, and that's all. It's possible to discuss on aesthetics, but math is math...

(We can use different additional techniques: stand, dilutions, stain developers, POTA... but always there are the BTZS graphs to explain how it works...)

Pere Casals
19-Jul-2016, 07:17
bigger film needs more light...

Not


Yes, a 8x10 (80 sq inch) need more light (photons) than 4x5 (20 sqi), but both need the same amount of photons per sq inch.

As a 8x10 takes more circle of image it also takes more photons at the same aperture. So same aperture then same shutter speed, independent of film format.

so easy : )

Randy Moe
19-Jul-2016, 07:21
Yes, a 8x10 (80 sq inch) need more light (photons) than 4x5 (20 sqi), but both need the same amount of photons per sq inch.

As a 8x10 takes more circle of image it also takes more photons at the same aperture. So same aperture then same shutter speed, independent of film format.

so easy : )

Yes, of course, we use a different area aperture of a bigger lens and IC.

But the math is the same.

Edit, I was not referring to you Pere! Your posts are most welcome and informative.

Pere Casals
19-Jul-2016, 07:49
I was not referring

Of course, I understood it... I just was pointing the source of the confusion you mean, and some people showed, not taking into account than for the same aperture Lux·Second are the same in all the circle surface... except for falloff effect, of course...

Drew Wiley
19-Jul-2016, 13:12
The Zone System is like a rubber band. You stretch it to fit your own needs. Learn it, then forget it once exposure and development become predictable. And of
course, it is never a substitute for real sensitometry at an analytic or research level. Just to convenient tool kit, one among many.

Jim Noel
19-Jul-2016, 13:37
Possible, but unlikely. The ISO standard doesn't specify a developer formula. I typically use XTOL and D-76 for this sort of thing.

Factoring in the 2/3 stop measurement difference combined with the fact you're targeting a higher density than 0.1, I'd have expected an EI more than a stop below ISO, and yet you're at 500. Can't argue with whatever works though.

And in the end, in the field a working EI depends mostly on how we meter. But ZS tests (or other similar tests) don't factor that in .

Determination of the ISO is done with a developer not generally available, and which I doubt many would want in their darkroom. The standards for the ISO determination are very precise and everything is strictly followed - developer, temperature, agitation, age of the film, age of the developer, on and on. It is node in a laboratory,not a camera. I don't even look at the ISO on film. I buy in fairly large quantities, and all of an order with the same emulsion number. Then I do my own testing which takes no more than an hour from exposure to hanging film to dry. Also, because I have a variety of lenses from different eras, the EI is adjusted for actual light transmission of each. This testing had to be done only once for each lens, and produced a factor to be applied to my established EI.

Michael R
19-Jul-2016, 17:59
Jim, the developer specification was dropped from the standard.

I would say the notion ISO speed determination is some sort of esoteric "lab" thing outside of cameras and real world photography is a fallacy. In fact the ISO speed determination is rooted directly in print quality (the Zone System standard is not).

Also note while Zone System EIs are determined under flare-free conditions regardless of the equipment used, under actual shooting conditions flare changes where the low values fall relative to where they are placed - and therefore also changes film speed as defined by the Zone System (increasing it). Flare is one reason why we don't necessarily make the negatives we think we are making, and also why we shouldn't ascribe the level precision we often do to any exposure system. Luckily, the end-to-end process and materials afford us the latitude to make great prints whether or not we are correct regarding what is actually going on.

I'm not arguing against EIs per se. We all might meter scenes differently, and most importantly, we might all judge scene luminance values differently. But none of these real variables are accounted for in personal EI testing. That's where the misunderstanding is. We are told EIs account for all kinds of personal variables. They don't. They only thing an EI really controls for is the use of a developer that substantially either increases or decreases film speed.

It's about understanding what a given test is or isn't telling you. Understanding the relationship between ISO speed and a Zone System EI obviates the need to do the EI test in most cases. Of course there's nothing wrong with running the test anyway, but gaining an understanding of some of the sensitometry can ultimately lead to simplified working methods and a focus on printing - where the control really is.

stawastawa
30-Sep-2016, 20:52
Determination of the ISO is done with a developer not generally available, and which I doubt many would want in their darkroom. The standards for the ISO determination are very precise and everything is strictly followed - developer, temperature, agitation, age of the film, age of the developer, on and on. It is node in a laboratory,not a camera. I don't even look at the ISO on film. I buy in fairly large quantities, and all of an order with the same emulsion number. Then I do my own testing which takes no more than an hour from exposure to hanging film to dry. Also, because I have a variety of lenses from different eras, the EI is adjusted for actual light transmission of each. This testing had to be done only once for each lens, and produced a factor to be applied to my established EI.

And what is your testing method Jim?

Leigh
30-Sep-2016, 21:23
i strongly recommend you buy and become familiar with a standard exposure card.

These have an 18% reflectance gray card on one side, and a gray scale with color swatches on the other side.
The 18% gray card is used for taking reflected light readings. This is industry standard.

The other side lets you evaluate the negative to see how highlights and shadows resolve, as well as colors.

Here's the original Macbeth color checker, though no longer marketed under that name:
https://www.bhphotovideo.com/c/product/465286-REG/X_Rite_MSCCC_Original_ColorChecker_Card.html
It's been the industry standard for decades. The colors resolve correctly under a wide range of light sources.

Here's the Wikipedia page that explains it:
https://en.wikipedia.org/wiki/ColorChecker

Here's one good example from B&H ( have no personal experience with it but it looks good):
https://www.bhphotovideo.com/c/product/817209-REG/DGK_Color_Tools_DKCPRO_DKC_Pro_Multifunction_Color_Chart.html

And here's a somewhat larger one from Kodak:
https://www.bhphotovideo.com/c/product/813250-REG/Kodak_1277144_Gray_Card_Plus_9x12.html

These all (theoretically) accomplish the same thing, which is to provide a standard subject for you to shoot.
It provides a basis for comparing different films, processing methods, and lighting.

- Leigh

Randy Moe
30-Sep-2016, 21:52
i strongly recommend you buy and become familiar with a standard exposure card.

These have an 18% reflectance gray card on one side, and a gray scale with color swatches on the other side.
The 18% gray card is used for taking reflected light readings. This is industry standard.

The other side lets you evaluate the negative to see how highlights and shadows resolve, as well as colors.

Here's the original Macbeth color checker, though no longer marketed under that name:
https://www.bhphotovideo.com/c/product/465286-REG/X_Rite_MSCCC_Original_ColorChecker_Card.html
It's been the industry standard for decades. The colors resolve correctly under a wide range of light sources.

Here's the Wikipedia page that explains it:
https://en.wikipedia.org/wiki/ColorChecker

Here's one good example from B&H ( have no personal experience with it but it looks good):
https://www.bhphotovideo.com/c/product/817209-REG/DGK_Color_Tools_DKCPRO_DKC_Pro_Multifunction_Color_Chart.html

And here's a somewhat larger one from Kodak:
https://www.bhphotovideo.com/c/product/813250-REG/Kodak_1277144_Gray_Card_Plus_9x12.html

These all (theoretically) accomplish the same thing, which is to provide a standard subject for you to shoot.
It provides a basis for comparing different films, processing methods, and lighting.

- Leigh

Glad you posted those.

I have this in my always full cart. https://www.bhphotovideo.com/c/product/714596-REG/Tiffen_EK1527654T_Q_13_Color_Separation_Guide.html

I'll look again in the light of day.

Neal Chaves
1-Oct-2016, 08:23
Years ago I learned the method to find the correct developing time and EI for any film. I source was an article by William Mortensen. Mortensen wrote some excellent books and articles about basic sensitometry. The last time I did this test was when I abandoned Tri-X and switched to HP5+ due to cost about five years ago. I proceed as follows.

I set up my trays with my favorite developer HC110B (1:31). I pull out a sheet from the package in the dark. and then when the package is sealed again I turn on the room lights. This part of the test is done under the lights. I cut the sheet into five strips and mark them 1-5 by punching holes with a paper punch. Lets say the recommended time is 5:00. I want to see 3:00, 4:00, 5:00, 6:00 and 7:00, so I throw all the strips into the developer and agitate as usual until 3:00 when I move the No.1 strip over to the stop bath. Then I pull No.2 at 4:00, No.3 at 5:00, etc. I fix, wash and dry the strips as usual. What we are looking for is the best usable film DMax value. Obviously the film has been fully exposed! When strips dry lay down a page of news print on a table in good light. Find the strip through which the news print is barely visible. That's your developing time. Now to find the film speed.

Go outside in unchanging light conditions and expose five sheets and expose one at the manufacturers rating and then the other four at one half a stop and one stop less and one half a stop and one stop more. In the dark, develop them all together for your newly derived time. Contact print them together exposing and developing the paper for maximum usable paper DMax value. Pick out the best-looking contact print and you have your film speed.

Because my 7:00 negative looked the best on the first test, I did the test again with 7:00 as the central developing time and found that 8:00 was indeed too dense. This HP5+ time was the same as the as the developing time I had been using for Tri-X and film speed was also the same, EI400.

Many of the last generation of B&W gurus favored a development time of 5:00 for Tri-X and suggested an EI of 64-100. You can do the above test backwards, developing for 5:00 minutes and finding the film speed. I like 100. The difference between negatives exposed at 100 and developed for 5:00 is quite subtle. Both could be considered "normal" or N negatives. The 100 negative has slightly greater shadow and highlight detail that only a careful, knowledgeable viewer could detect. This slight improvement might not be worthwhile trading for two stops in the field. I do routinely rate HP5+ at 100 under powerful strobe light in the studio and it produces beautiful skin tones.

From here, if you are still with me, you can derive expansion and contraction schemes for both the 100 and 400 "normal negs". I do this by changing dilution rather than time. Make sure you have at least 1 oz. of the concentrated sauce for each 8X10 sheet or equivalent. For expansion I found that 3/4 oz. concentrate to 31 1/4 ozs. H20 yields an N-1 neg at a one stop loss in film speed and 1/2 oz. concentrate to 31 1/2 ozs. H20 yields an N-2 neg at a two stop loss in film speed. For contractions, 1 1/4 oz. of concentrate to 30 3/4 ozs. H20 yields an N+1 neg at a one stop gain in speed and 1 1/2 ozs. concentrate to 30 1/2 ozs. H20 produces an N+2 negative with a two stop gain in speed.

If you look at the chart of Tri-X film speed in Phil Davis' BTZS book you can easily pick out the film speed in HC110B 5:00 as EI 64.

Don't apply reciprocity exposure and development corrections for long exposures (1/2 sec. +) based on published data. Test for yourself and you may be surprised. I wasted a lot of time and effort producing long exposure negatives that were thick and flat. When I finally tested, I found no compensation was required for TXP out to one minute.

Peter De Smidt
1-Oct-2016, 09:30
That's good stuff, Neal. Mortensen's book on this is called Mortensen on the Negative. One possible difficulty, which is the same issue for Picker's Proper Proof, is that visually judging paper d-max is challenging. While that's true, in my opinion it's not a fatal flaw. We can judge well enough, and we can always tweak the process later if issues arrive. If "well enough" causes anxiety, then get a densitometer.

Kirk Gittings
1-Oct-2016, 09:45
Peter, I use Picker's method and teach it at a university level. Indeed students do have a hard time choosing the right d-max......at first (often times because they are looking at it in dim light) but they get the hang of it, usually the second time round.

sepiareverb
1-Oct-2016, 11:18
...I set up my trays with my favorite developer HC110B (1:31)...

Neal, did you rerun this test when HC-110 changed to the newer, less viscous 1L bottle version? I'm just finishing up my last bottle of syrup.

Jerry Bodine
1-Oct-2016, 11:38
(Ref Post #23)...no suppliers will ship HC110...

Neal-
FYI, Freestyle does ship HC-110. Back when the new HC-110 hit the market, I queried B&H to find out why they won't ship it and did not get a satisfactory explanation. Guessing it's because of an arrangement with their selected shipper.

Peter De Smidt
1-Oct-2016, 11:56
Peter, I use Picker's method and teach it at a university level. Indeed students do have a hard time choosing the right d-max......at first (often times because they are looking at it in dim light) but they get the hang of it, usually the second time round.

Exactly, Kirk. It's especially easy to fix if someone with experience is there to help.

Neal Chaves
1-Oct-2016, 18:38
If there was a difference, I never detected it. I'm happy with Ilfotec HC and it can be on my door in two days from B&H. Picker claimed that "Engineers at Kodak didn't know their ASAs from their elbows" when they rated TXP at 400. I think Kodak was suggesting a 5:30 time in HC110B. It is true that you get a very nice negative rated at 100 and developed for 5:00. Phil Davis' Wonder Wheel indicates 64 at 5:00. I use 100 in my studio where I have plenty of strobe power, but 400 at 7:30 outside.155708

Bill Burk
1-Oct-2016, 19:01
Picker used to hit kids on airplanes too...

Bill Burk
1-Oct-2016, 19:07
What I mean is ASA/ISO testing provides a certain/assured measure of film speed.

If you find speeds less or greater than the rated speeds when you test, it is likely your test method differs from the ISO standard in some way.

The best evidence I know is Panatomic-X which Picker found truly rated at 32 or maybe higher while everything else he found slightly less than rated speed.

I also find Panatomic-X rates higher than other films, relatively speaking. So I have to agree there is something special about the way some films test...

Pere Casals
2-Oct-2016, 04:15
DIY densitometer.

Option 1

I'd like to add that in these modern mobile days have mobile densitometers in our pockets.

Most smartphones have a high percission photocell at the top of front face, this is to regulate screen brightness upon ambient light.

Just download a Luxometer App, place the mobile under a lamp and take the reading in LUX, the distance to the lamp may be adjusted to read some 1000 Lux.

Then place the film on the mobile photocell and take the reading. Then calculation its easy, Log (Lux_without_film / Lux_with_film). Logarithm is the base 10 one, not the napierian one !!!


With my Xperia Z2 it works very accurate, now I've a precission clamp densitometer and calibrated wedges and I found it very accurate. Of course one can use MS Excel and not the calculator, so the curves are built automaticly, just entering the Zero reading (Lux_without_film) and the reading for each point.


Option 2

Scan your film with a calibrated stouffer (or the like) calibrated wedge at its side, it can be an IT8 transmission target, you crop the gray scale.

So make an area scan that includes the wedge and the film. Disable any scanner color correction: ICC, profiles, gamma, adaptative contrast... just take the image with its 16bit raw reading, save it in TIFF 16 bit format !!!

Then with any software like PS you can compare the (1 to 65535) values from the calibrated wedge to the tested film ones.


PD: The mobile Luxometer is high precission, but it's reading it's a bit directional compared to a dedicated handheld luxometer that has a dome, but to be used as a densitometer this is an advantage !

(If densities are beyond 2.5D then Zero Reading (without the film) should be 10000)

Ken Lee
2-Oct-2016, 05:44
And there is a simple reason for that, which almost nobody wants to know about, unfortunately. Suffice it to say if you plan on finding an EI using a Zone System-type test, you can skip that part and simply reduce film speed by 2/3 stop (or round it to either 1/2 stop of 1 stop).

One of the nice things about BTZS testing is that it completely bypasses the uncertainty and inconsistency of the photographer's choice of scene and approach to metering it.

Speaking of consistency, the vast majority of the 122 film/developer tests which come with the BTZS Plotter program (http://btzs.org/Software/Plotter.htm) confirm Michael's proposition.

http://www.kennethleegallery.com/images/forum/WinPlotterTests.png

Bill Burk
2-Oct-2016, 08:11
Speaking of consistency, the vast majority of the 122 film/developer tests which come with the BTZS Plotter program confirm Michael's proposition.

Nice addition to my "confirmation bias"...

No matter how I look at it, be it on paper, in testing or in practice... It all boils down to 2/3 stop...

I am much happier with the black and white negatives I make now that I give 2/3 stop increased exposure, than I was when I set my meter exactly at the ASA/ISO rated speed of the film.

neil poulsen
2-Oct-2016, 08:59
To Randy's point, I have a 150mm lens that has a consistent 1/2 sec shutter speed and use those test results for all my lenses. Using A.A.'s approach, we end up with about 5 development: N-2, N-1, etc. (Not 10 or 15.) Given that wide granularity (only 5), why test different lenses? I suppose this practice bears some testing in, and of itself. But, it appears to work for me.

It just occurred to me, I sold that 150mm lens. (Oh dear.)

I'll add that I stick to one paper, one developer. While I think my black and white calibrations are a bit involved, I need only do them once in a few years.


Thanks for the reply. I see your point and a major reason I don't use Zone is the whole added personalization to a lens, aperture, and shutter error combo. i play with too many combos to do that. I do test my shutter speeds, but don't fix shutters, simply adjust to actual and I am often using flash, so...

All good!

Neal Chaves
2-Oct-2016, 09:14
I read all of Picker's writings and tried a few of his products too when I was naive. He himself said "I'm no film tester.", yet he would happily examine your film for five bucks and give you your own personal, secret mantra that you were not to share with anyone else, would be your salvation and deliver you from the hell of unprintable negatives, unable to make "fine prints".

Peter De Smidt
2-Oct-2016, 09:33
A slightly modified Zone VI Workshop system, I prefer 1/3 stop increments, has worked well for me for a long time.

neil poulsen
2-Oct-2016, 09:45
I'm wondering about (and perhaps question?), comparisons of Ansel Adams method to set film speed with the ANSI/ISO standard. Using the zone system, we expose for the shadows and develop for the highlights. That is, we know as part of the process, we'll be using different development times. Adams' method of determining film speed is well designed for this approach. (Which, is why I'll stick with Adams' method for determining film speed.)

On the other hand, "typical" practice is to use the film manufacturer's recommended film speed (based on ANSI/ISO?), and then use a single development time that's recommended by the developer's manufacturer. Back to wondering, is the ANSI/ISO approach designed for using a single, manufacturer recommended development time?

Is the developer's manufactured recommended development time (per different films) itself based on an ANSI/ISO standard, in which case, one would expect one ANSI/ISO standard to be consistent with the other?

Bruce Barlow
2-Oct-2016, 09:56
Picker's "atypical" approach was to expose the highlights for Zone VIII, and take what you get in the shadows, mostly. He didn't much like shadow values below Zone III. Speaking for myself, I have found this method to be close enough for photography, and I rarely have bad exposure. Extremely rarely. And if my development time is nailed down, which it is, the negatives are lovely.

Fred advocated "N" development, and "N+1 1/2," to split the difference between paper grades and give you more flexibility. That said, I've made and developed a lot of "N+1 1/2" negatives, and I'm not sure I ever printed one instead of the "N" negative, but that's me. YMMV.

Fred also would make a negative according to what the meter told him to do, and then routinely would make another opening up a full stop. He told me with a wink that the one with more exposure was the one he typically printed...

As far as ASA/ISO, for the films I use - Tri-X, TMY, and HP5, these days I just use 200, or half the rated speed. Again, close enough for photography, and if I get a little more exposure in the shadows, I'm a happy man. I deserve to be happy.

I don't know about hitting kids on airplanes, but Fred kicked puppies and threw cats under cement mixers. :-)))

Neal Chaves
2-Oct-2016, 11:33
When Adams says, as he does many times in Making of Forty Photographs and his other writings "I felt the shadows needed extra support, so I placed them on Zone IV instead of Zone III." he is effectively cutting film speed in half, from his usual 160 for TX320 to 80, close to Davis' speed of 64 for TX at 5:00.

Ken Lee
2-Oct-2016, 11:48
"Shadows" is a variable and subjective term. Is it a white cat in the shade, a black horse in the shade ? Should they be always be placed on the same Zone ?

Leigh
2-Oct-2016, 11:59
"Shadows" is a variable and subjective term. Is it a white cat in the shade, a black horse in the shade ?
Should they be always be placed on the same Zone ?
That's a very obvious point that's often overlooked.

- Leigh

Michael R
2-Oct-2016, 12:10
I'm wondering about (and perhaps question?), comparisons of Ansel Adams method to set film speed with the ANSI/ISO standard. Using the zone system, we expose for the shadows and develop for the highlights. That is, we know as part of the process, we'll be using different development times. Adams' method of determining film speed is well designed for this approach. (Which, is why I'll stick with Adams' method for determining film speed.)

On the other hand, "typical" practice is to use the film manufacturer's recommended film speed (based on ANSI/ISO?), and then use a single development time that's recommended by the developer's manufacturer. Back to wondering, is the ANSI/ISO approach designed for using a single, manufacturer recommended development time?

Is the developer's manufactured recommended development time (per different films) itself based on an ANSI/ISO standard, in which case, one would expect one ANSI/ISO standard to be consistent with the other?

I'll try to address your question. A few things:

1) Regarding contrast/development times and film speed, the ISO speed methodology is rooted in print quality studies. The studies found that rather than basing film speed on a fixed density target, it is the contrast of the shadows in relation to overall contrast that should determine film speed. ISO is a "shorthand" for this methodology. Ultimately what we care about is how the shadows separate in relation to total contrast. This seems obvious, but note the Zone System doesn't do that. It always locates a fixed density for the speed point whether you are developing + or -. The important point here is that the speed underlying an ISO rating doesn't move around nearly as much as a Zone System EI when the film is developed to different contrasts. I think that was what you were asking.

2) It bears repeating that barring the use of special purpose chemicals/materials, when developing to N contrast, Adams's speed method finds a speed 2/3 stops below ISO because the Zone System speed incorporates the pre-1960 safety factor, which was established earlier when materials were less consistent and meter technology was still relatively primitive. If the Zone System had been updated for the smaller safety factor, an Ansel speed test would find the same speed as ISO (the speed point would be at Zone I 2/3). The important point here is that the Zone System EI is nearly always lower than the ISO speed by a predictable amount. That's what exposure fundamentals tell us, and the Zone System test therefore doesn't "reveal" new information. Said another way, if you do a Zone System test on a 100 ISO film and find an EI of 64, all you've done is confirm the film is ISO 100.

3) The Zone System EI test is flare free - ie what you want in a test. But flare under shooting conditions changes where the shadows fall compared with where we place them. Flare both raises and compresses the lower values. From a Zone System perspective flare has the effect of increasing film speed.

Again, I'm not arguing against personal EIs. But if we're going to go to the trouble of running these tests, a little theory goes a long way in helping us understand what we are doing, what a given test does and doesn't tell us, what we can and can't conclude, what controls we do and don't have etc. It can simplify things.

EIs are mostly about how we meter (and printing skill). The trouble with most EI "tests" is that they don't address print quality. The Zone System EI, for example, is not based on a "higher" standard than ISO (although we are often taught so). It can only be a starting point even under the best of circumstances. Then you have to print and see if you consistently would prefer giving the film more or less exposure.

Pere Casals
2-Oct-2016, 12:56
When Adams says, as he does many times in Making of Forty Photographs and his other writings "I felt the shadows needed extra support, so I placed them on Zone IV instead of Zone III." he is effectively cutting film speed in half, from his usual 160 for TX320 to 80, close to Davis' speed of 64 for TX at 5:00.


To me, first half of BTZS book explains all. Second part is practical advice... The first part is the interesting one.

A graph like this one tells everything.

155716

A Spot meter will say what negative density will render every spot of the scene, if we look a paper with the chart, this a way to learn.

Spots that are at 1.3(Log) / 0.3 (Log to Stops) = 4.3 Stops underexposed (at box speed) will be in the toe, so with little or no detail.

So if we expose for a particular spot of a scene, spot meter says "0" for it, ("n" point at the graph), that point will always have a density of 0.1(base+fog aprox)+0.1+0.8 = 1.0D. (standard development)

So with the family or curves with diverse developing times Spot Meter will tell the Max and Min density of the negative, and if a particular spot of the scene is in the linear range.

I feel I've learnt a lot by looking the calibration charts while metering the scene, and then cheking if the predicted density was accurate after developing. And then looking if detail was there at shadows and higlights, and then realizing if the negative was easy to print or not...


If scene is not very contrasty it's mostly good to overexpose an stop. With a contrasty scene we have to expose to distribute the dynamic range in order to not sacrifice one side when we have room in the other. Then we'll have open options for printing.

I think this is the basics of learning the thing: Charts & knowing where each scene spot is in the chart.

Leigh
2-Oct-2016, 14:31
I'll try to address your question. A few things:
Excellent explanation, Michael.

- Leigh

Pere Casals
2-Oct-2016, 16:19
Using the zone system, we expose for the shadows and develop for the highlights....



I'll try to address your question. A few things: ...


Michael, I also think it's an excellent explanation about ZS... BTZS just makes it clear in a graphic way.

Perhaps the most important statement of the ZS it is not to expose for shadows, as this is someting evident, the important statement is to develop for the lights, so negative will have a density range that will be printable, with less problems, to obtain a suitable scene interpretation.

At the end when we meter we have to know what areas of the scene will be (tonality) compressed in the toe, what areas will be compressed in the shoulder (if our film has shoulder) and at what density will fall our highlights after processing N+/-.


What I mean is that, at the end, ISO rating is just a reference, so "Then you have to print and see if you consistently would prefer giving the film more or less exposure." as Michael says, and this needs to be done in both cases: using box speed as a reference o using presonal EI.


Kodak and Fuji films have very useful exposure vs density charts in datasheets, exposures have actual lux-second values. Other manufarers only say "relative exposure" for their charts.

So if you can read (luxometer) or calculate the amount of light (lux-second) that arrives to a GG spot you'll know what density will have that spot in the negative, and if you are in the toe , the linear area, or the shoulder.

Having the skill to know how many lux-second arrive to any GG (negative) point you want to check is a way of having control of the situation. Saturated colors may differ a bit because photometer/film spectral sentivity.

Drew Wiley
3-Oct-2016, 09:41
It's the character of the shadows that counts, not just some hypothetical end zone goal. Different types of film differ in this respect, and all of this is tied to your
particular aesthetic objectives. I think in terms of the shape of the toe of the film. In this respect, both ISO standards and the Zone System can be misleading. If you do use a densitometer to evaluate your film using a predictable step tablet, you'll want to pay attention to how evenly the reproduced steps are space, density-wise, and how far along the scale. Basic curve plotting skills are important. But there is often a difference between lab performance of these films and how they respond in the real world under more complex variables. Otherwise, unless you just happen to enjoy the technical side of this, all the math and so forth if apt to be a wild goose chase unless you understand what a goose looks like first. In other words, you might be better off just shooting and printing, shooting and printing, until it makes sense. Trying to quantify a lot of variables at once can be problematic.

stawastawa
3-Oct-2016, 10:03
Trying to quantify a lot of variables at once can be problematic.
Yup!

jvo
3-Oct-2016, 10:24
Kodak had a nice tip for evaluating your negatives.

Place your negative over top of a newspaper. If you can just read the type through the highlight area, and there is detail in you shadow area you pretty much have a good negative.

After 40 years of printing for others I still find this to be good advice.

Bob



whatsa newspaper?;)

Pere Casals
3-Oct-2016, 18:19
It's the character of the shadows that counts, not just some hypothetical end zone goal. Different types of film differ in this respect, and all of this is tied to your
particular aesthetic objectives. I think in terms of the shape of the toe of the film. In this respect, both ISO standards and the Zone System can be misleading. If you do use a densitometer to evaluate your film using a predictable step tablet, you'll want to pay attention to how evenly the reproduced steps are space, density-wise, and how far along the scale. Basic curve plotting skills are important. But there is often a difference between lab performance of these films and how they respond in the real world under more complex variables. Otherwise, unless you just happen to enjoy the technical side of this, all the math and so forth if apt to be a wild goose chase unless you understand what a goose looks like first. In other words, you might be better off just shooting and printing, shooting and printing, until it makes sense. Trying to quantify a lot of variables at once can be problematic.


I agree that the character of the shadows are very important in the final print, anyway there are two ways to work the shadow's character, this is how shadow's range is compressed.


Option 1:

One way is to compress the shadows placing them in the toe of the negative.


Option 2:

The other way is to place the shadows in the linear area of the negative but placing them in the shoulder of the paper. Similar compression can be achieved.



At the end Option 2 gives more choices when printing the shadows. But this has also drawback with contrasty scenes, as placing shadows in the linear area of the curve also takes more dynamic range of the negative, because with "Option 2" strong highlights can have a lot of density on the negative, can be more difficult to print, and perhaps can even be lost.

Well, at least this is the conclussion I've arrived... but I'm still fighting to master those skills. Doing that in Photoshop it's very straight, doing the same in the darkroom requires a true photographer there. Worth to learn it.

Bill Burk
3-Oct-2016, 20:44
The way I understand it, you get an S-curve with paper... and you get a hockey stick or J-curve with the film. Shadows are pleasingly compressed when you use a little bit of the optional J in the toe of the film as well as the given S of the paper. If you shoot up on the straight line, you only get the S-curve of paper (only the shoulder compression on the print). You also get another "J" superimposed by the action of flare.

I also believe the film and paper curves are able to be controlled by the manufacturer, have been specifically designed for the purpose, and that the shapes of both curves were designed so that they work together this way. You are expected to use some of the toe for your shadows. Those who shoot up on the straight line are shooting off their... well they're shooting off a lot.

So why do I still shoot up on the straight line? Because the difference, though it exists and can be demonstrated and measured, is not yet significant to me. Maybe one day I'll be sensitive enough to want to use the toe. But for now I'm happy with the look of my prints that I get when I use the straight line.

I really like the demonstration that Ralph Lambrecht put in "Way Beyond Monochrome" because it shows the delicate differences in the shadows in a way you can really talk about. The bench under the window looks better when shot on the toe when compared to the similar best print he could make when he used the straight line.

Bottom line: If you see something you like, try it both your old way and the way the photographer did it the way you liked. If the photographer's tip worked to give you something different than you would have otherwise gotten, and you like it... you've just added another trick to keep up your sleeve.

neil poulsen
4-Oct-2016, 04:13
I'll try to address your question. A few things:

1) Regarding contrast/development times and film speed, the ISO speed methodology is rooted in print quality studies. The studies found that rather than basing film speed on a fixed density target, it is the contrast of the shadows in relation to overall contrast that should determine film speed. ISO is a "shorthand" for this methodology. Ultimately what we care about is how the shadows separate in relation to total contrast. This seems obvious, but note the Zone System doesn't do that. It always locates a fixed density for the speed point whether you are developing + or -. The important point here is that the speed underlying an ISO rating doesn't move around nearly as much as a Zone System EI when the film is developed to different contrasts. I think that was what you were asking. . . .

That's interesting . . . of which paper?

How do we know that the film being purchased by a given photographer will ever be used on that paper? (Or papers?) In this case, does the film speed not become dependent on the paper (or papers) selected for the print studies? I may be over simplifying a bit, especially since I'm not familiar with the methodology involved in the standard. But personally, I would prefer that film speed determination be independent of a given, or a group of papers. There are so many different papers (and different behaving papers) that are available, even now.

It may sound like I'm attaching the ANSI/ISO standard, but I'm really not. Perhaps I'm more playing devil's advocate.

As to my own testing, it's true that the Zone System film speed test doesn't rely on print studies directly. Recall that it determines the film speed that yields a developed Zone I exposed sheet of film that prints 0.01 density units above film base plus fog. Then during subsequent (at least my) Zone System testing, maximum paper black (for the paper that I actually use) is determined by printing through an unexposed, but developed (at the developer's recommended time and temperature) sheet of film. That is, it's determined by printing through a film base plus fog sheet of film. Once I determine this black by varying exposure time on my enlarger, I determine N development by seeing which development time gives me a Zone VIII that I like, when printed on (my selected) paper at the enlarger exposure time that yields maximum black.

So while Zone System film speed tests themselves are independent of print quality studies (which I tend to prefer), Zone System methodology itself does come back to print results on the paper that is actually used by the photographer.

To address a possible hanging question, how did the value "0.01" above film base plus fog originally get chosen? I suspect that it was the minimum value that would actually work in practice. Of course, to determine what "works in practice", would need to, in some measure, be based on print studies.:)

With all this discussion, I fear that we're getting beyond the OP's original question. But, the discussion has been interesting, none the less.

Pere Casals
4-Oct-2016, 05:30
The way I understand it, you get an S-curve with paper... and you get a hockey stick or J-curve with the film. Shadows are pleasingly compressed when you use a little bit of the optional J in the toe of the film as well as the given S of the paper. If you shoot up on the straight line, you only get the S-curve of paper (only the shoulder compression on the print). You also get another "J" superimposed by the action of flare.

I also believe the film and paper curves are able to be controlled by the manufacturer, have been specifically designed for the purpose, and that the shapes of both curves were designed so that they work together this way. You are expected to use some of the toe for your shadows. Those who shoot up on the straight line are shooting off their... well they're shooting off a lot.

So why do I still shoot up on the straight line? Because the difference, though it exists and can be demonstrated and measured, is not yet significant to me. Maybe one day I'll be sensitive enough to want to use the toe. But for now I'm happy with the look of my prints that I get when I use the straight line.

I really like the demonstration that Ralph Lambrecht put in "Way Beyond Monochrome" because it shows the delicate differences in the shadows in a way you can really talk about. The bench under the window looks better when shot on the toe when compared to the similar best print he could make when he used the straight line.

Bottom line: If you see something you like, try it both your old way and the way the photographer did it the way you liked. If the photographer's tip worked to give you something different than you would have otherwise gotten, and you like it... you've just added another trick to keep up your sleeve.



Bill, thanks for this explanation.

After you pointed it I've just read the preface of that book:

"The book will take the reader on a journey, which will transform ‘trial and error’ into confidence and the final print into something special."

I'm to read that book.

I guess that combination of S and J shapes of paper and film come from refinements that evolved upon market acceptation. This is an imaging culture that took more than a century of artistic-industrial feedback.

Also from what you point, I'll make tests by bracketing, thus placing the shadows a bit in the toe and not, and later looking how both negatives can be worked in the darkroom.

Thanks again.

Drew Wiley
4-Oct-2016, 11:02
Different curve shapes in film were engineered for different applications, though quite a few black and white films land somewhere in the middle, for versatility.
In the old days you had an "all toe" film, Plus-X Pan, marketed to studios with controlled lighting and a lot of potential high-key applications, like Caucasian brides
in white wardrobes. Then you had a "true straight line" film (again, a bit of hyperbole, but descriptive nonetheless), namely, Super-XX, which would handle extreme lighting ranges with consistent gradation. This is a very different thing from merely "minus" or "compensating" development, which might successfully
squeeze the ends together, but at the expense of midtone texture or microtonality. Then there was a popular film with intermediate curve characteristics, Tri-X.
Of course, all kinds of other films were on the market; but these are the ones a Photography School student would be routinely expected to understand. Today
about the closest thing to Plus-X would be Delta 100, to Super-XX, TMax400 (though Fomapan 200 fits the straight-line niche better, but not in a practical sense),
and we've got all kinds of popular mid-application films, like FP4. I might choose a completely different film on a rainy or foggy day than in high contrast settings, due to the nature of the curve. For example, the pronounced S-curve of Pan F can do wonderful things in soft lighting, but be hell to print given a high
contrast subject. It has relatively little usable range, maybe just Zone III to VII. But a straight-line film might give you up to twelve full stops of range. Most
films are somewhere in between, and a good example of that category available in many formats would be FP4, which would also be an excellent film to learn
the basics on.

Jerry Bodine
4-Oct-2016, 12:13
...As to my own testing, it's true that the Zone System film speed test doesn't rely on print studies directly. Recall that it determines the film speed that yields a developed Zone I exposed sheet of film that prints 0.01 density units above film base plus fog...

Neil-
I think your recollection may be a bit fuzzy. ZS film speed is base on 0.10 density above fb+fog (not 0.01). Just a typo maybe?

Drew Wiley
4-Oct-2016, 13:07
If that's true, it simply indicates a kind of generic approach that is potentially misleading. A few films start showing distinct gradation merely .05 above fbf, most
need around .15, while some need up to .30. So in most cases you're dealing with the degree of the slope and not discrete zones. In other words, it's all relative,
both with respect to how many zones the world is divided into, and what the nature and reproduction characteristics of those zones actually are, especially when
you're talking about either the toe or shoulder to the film. I'm not discouraging the exercise itself, but merely indicating how relative everything is, and how once
you've gotten to first base, there is still a stretch to home.

Jerry Bodine
4-Oct-2016, 15:47
No argument there, Drew. Really just pointing out AA's recommendation in The Negative that Zn I net density is .10 above fb+f. In Way Beyond Monochrome, p.213, the recommendation is to set the speed point at net density 0.17 and refers to that as Zn I.5 and provides the reasoning for this.

Drew Wiley
4-Oct-2016, 16:04
Of course, those AA how-to books were written long ago, when specific film choices were largely different, not to mention papers. But even then, this was a generality, a mere starting point. The elegance of the Zone System is that each zone hypothetically relates to one distinct f-stop or aperture of exposure difference, which would ideally equate to a consistent amount of density change on the film, except that, among films of that era, only Super-XX and Color Separation Film were capable of a consistent very long straight line. So unless you happen to be Minor White, who would start levitating at Zone VIII due to either an attempted alien abduction or some near-death experience, all of this has to be taken in stride. I don't even think about the ZS anymore except in conversations like this one. It was a helpful learning tool; but it can equally become a ball and chain, engendering Medieval scholastic debates about how many Zones the world is comprised of, until your ship falls of the edge.

sepiareverb
4-Oct-2016, 16:11
Years ago I learned the method to find the correct developing time and EI for any film. I source was an article by William Mortensen...

I gave this method a go with Rollei Ortho 25, a film I quite like for how it renders what I see, but have always had trouble exposing and developing well. I ran the developing time test using Rodinal 1:50, and got 7 minutes. I then shot a half a roll on an overcast day and got an ISO of 20. Will re-shoot the test on a sunny day as soon as one arrives in NE VT. This seems like the simplest means of getting there to me. I've just gotten in some ORWO N74 (35mm) and will use this to land my ISO and developing time in a fraction of what it used to take me. Thanks!

Luis-F-S
4-Oct-2016, 19:00
Newbie question. Getting ready to shoot my first LF 8x10. Using HP5 film. Most likely using Ilford Ilfotec HC developer. Reading about calibrating film and and using a Densitometer...... I don't have a densitometer and my head exploded when I tried to understand the process.

Well, you've sort of answered your own question, if you don't own or have access to a densitometer. You'll probably get 100 responses to this question, with at least 40 "methods" that may or not be correct. There have been several shortcuts offered, ie use a speed, half of the film box speed, etc. While these approximations may be perfectly adequate in most situations, it won't exactly replace the long and exacting methodology in Adams' (and others') books. I would suggest getting a copy of Fred Picker's Zone VI workshop that has many simpler procedures that will get you in the ball park, so your head won't explode. Have fun! L

Neal Chaves
4-Oct-2016, 19:20
If you ever see the Ansel Adams Autobiography, check out the photo made of Adams by his disciples. He is dressed in a white robe and like Moses is holding this big tablet engraved with "All light is divided into ten zones." However, whoever made the photo was not even in the exposure and development ballpark, harsh contrast with all the highlights, including St. Ansel's robe completely blown out (must have been TMax).

Leigh
4-Oct-2016, 19:35
...with all the highlights, including St. Ansel's robe completely blown out (must have been TMax).
They neglected to account for additional exposure due to St. Ansel's radiance.

- Leigh

neil poulsen
4-Oct-2016, 20:29
Neil-
I think your recollection may be a bit fuzzy. ZS film speed is base on 0.10 density above fb+fog (not 0.01). Just a typo maybe?

That's true; I wrote this in the wee house and was off a decimal point. Thanks.

Making that change, I believe the points are still valid.

Bill Burk
4-Oct-2016, 20:54
I don't think anyone answered the why's about 0.10

When ASA was being worked on, there was a contingent that wanted a fixed density reference (and 0.10 is as good an arbitrary threshold as any), and a team that specified 0.3 times the average gradient (that point in the toe which really mattered according to the statistics taken from focus groups who looked at tons of prints).

They settled the argument by locking in the development at the amount that fits the average subject luminance range to grade 2 paper including flare (works out backwards to be 0.62 gradient).

At that gradient, 0.3 times the average gradient is at 0.10 net density. This made everyone happy.

Pere Casals
5-Oct-2016, 03:21
No argument there, Drew. Really just pointing out AA's recommendation in The Negative that Zn I net density is .10 above fb+f. In Way Beyond Monochrome, p.213, the recommendation is to set the speed point at net density 0.17 and refers to that as Zn I.5 and provides the reasoning for this.


I'm speaking from the point of view I've as the learner I'm... repeating a bit what I've learnt here these days...


I think that at the end this makes little difference. From 0.10 to 0.17 there is 0.07. In exporure log terms (ISO standard...) this is E = 0.07 * 1.3/0.8 = 0.11, converting to stops (divide by 0.3) this is 0,47 stops.

So we are talking about if we use 0,47 stops more of dynamic range at the shadows side or not for the reference. So we are talking about how the reference is placed, not about how we use a particular film, and how we metter.

If we place reference 1/2 step up or down we'll end shooting 1/2 step down or up...


Those 0.47 stops of useful (or not) dynamic range are in the toe, so if that area is to be used or not it depends on the toe character of the film (long, short...), developer and perhaps agitation... But specially it will depend on if the aesthetics of those shadows likes to the photographer and if we want a versatile neg or not.



Perhaps, as allways, testing is important. What may clarify it is to bracket exposure for deep shadows, and then see how it looks to us after processing particularities. Another concern is how easy it prints...

Pere Casals
5-Oct-2016, 05:26
I don't think anyone answered the why's about 0.10

When ASA was being worked on, there was a contingent that wanted a fixed density reference (and 0.10 is as good an arbitrary threshold as any), and a team that specified 0.3 times the average gradient (that point in the toe which really mattered according to the statistics taken from focus groups who looked at tons of prints).

They settled the argument by locking in the development at the amount that fits the average subject luminance range to grade 2 paper including flare (works out backwards to be 0.62 gradient).

At that gradient, 0.3 times the average gradient is at 0.10 net density. This made everyone happy.



At the end the ISO standard (last is ISO 2240:2003 norm) it's an industrial standarization norm. This tells user that scene areas underexposed by some 4 stops still will be in the straight line. The norm considered than the stright line starts at +0.1. This is a bare convention, a reference, as we say 0șC for ice melting temp, or the meter definition.


ISO rating is a very good industrial norm. A norm has to be clear, consistent and repeatable. And ISO rating worked very well industrially for consumer market, an F5 or an F65 always got perfect automatic exposures (well, 95% of chances).

The problem happens when we want to use an industrial norm as an artistic tool: it do not works, what is beauty or what is artisctic expression it is beyond what ISO guys can deal with ...without becoming crazy :)

LF guys do not work with their 0,62 ISO gradient... they use all sorts of tricks to do the counter. They do N+/- , compress here, burn there... And first they try to do with a film is to shot it at a different speed than box states :)

So perhaps fine print imaging culture (or subculture) is a bit allergic to the ISO norms, that knowledge is in books like the one you pointed... "way beyond monochome" !

Michael R
5-Oct-2016, 06:44
That's interesting . . . of which paper?

How do we know that the film being purchased by a given photographer will ever be used on that paper? (Or papers?) In this case, does the film speed not become dependent on the paper (or papers) selected for the print studies? I may be over simplifying a bit, especially since I'm not familiar with the methodology involved in the standard. But personally, I would prefer that film speed determination be independent of a given, or a group of papers. There are so many different papers (and different behaving papers) that are available, even now.

The original print studies were done using lots and lots of different materials. One of the nice things about the speed method underlying ISO is it controls for different film curve shapes.

Obviously once you begin using a film and paper combination, you have to find an EI meter setting that consistently works best for you. You begin somewhere, and then through your own printing you decide whether or not you consistently need more or less negative exposure. There will always be some trial and error involved, because an EI has mostly to do with how you meter a scene, and how you print. A Zone System EI is as good a place to begin as any (including ISO), but no better, no more precise (due to flare etc).


To address a possible hanging question, how did the value "0.01" above film base plus fog originally get chosen? I suspect that it was the minimum value that would actually work in practice. Of course, to determine what "works in practice", would need to, in some measure, be based on print studies.:)


I know you mean 0.1. It was easy to measure. Before and after the print judgement studies and resulting speed methods leading to the fractional gradient method, there was a desire to determine speed using a fixed density, because it was easier to measure. DIN used 0.1. The British standard later moved to 0.1 as well (again, due to ease of measurement). There were other standards such as 0.2. While 0.1 did not correlate as well with print judgement speeds as the fractional gradient method, it did correlate better than other methods. Subsequent work was done to find a way of bridging the 0.1 fixed density method to the fractional gradient method. This led to the Delta-X method, which uses 0.1 combined with contrast criteria, to give close estimates of fractional gradient speeds. Delta-X is hidden within the ISO standard, which finds the speed point at 0.1 when certain contrast criteria are satisfied, and therefore effectively finds the hidden fractional gradient speed (which is about a stop below 0.1). As noted in my earlier post, the fractional gradient speed (ie the speed underlying ISO) does not move around as much when film is developed to different contrasts.

To summarize, the ISO method is a "shorthand" way of satisfying the fractional gradient (which correlates well with print judgement study speeds) criteria, using the handy 0.1 measurement reference point. When developing N, the Zone System finds the same speed minus 2/3 stop since it uses the older, larger safety factor.

You always have to start somewhere. If we know a little about ISO and Zone System speeds, we realize two things (or more) about personal EIs: 1) ISO is as good a starting point as the Zone System, and/or 2) Barring the use of special purpose processes/materials, subtracting 2/3 stop from ISO gives you the Zone System EI, which obviates the need for the test. So if in (1) you decide you want to start with a Zone System EI instead of ISO, just subtract 2/3 stop. Then evaluate over time using prints.

Drew Wiley
5-Oct-2016, 09:06
Just be aware that if you use the same type of film in roll version for the sake of economy and bracketing convenience, and then try to equate the results to sheet film, you've not only got a potentially different flare factor, but even worse, a much greater fbf due to the significantly greater antihalation layer density. Not all
densitometers have a small enough aperture to read just the undexposed edges of film, so in these cases, you might need a wholly unexposed frame for reference.

Pere Casals
5-Oct-2016, 13:17
Just be aware that if you use the same type of film in roll version for the sake of economy and bracketing convenience, and then try to equate the results to sheet film, you've not only got a potentially different flare factor, but even worse, a much greater fbf due to the significantly greater antihalation layer density. Not all
densitometers have a small enough aperture to read just the undexposed edges of film, so in these cases, you might need a wholly unexposed frame for reference.

Also sheets usually come from different master rolls, with different base, and perhaphs from different emulsion batches. Also film freshness can be different.

Randy Moe
5-Oct-2016, 13:47
This thread is starting resemble any alt print digital negative thread.

Custom curves...

Pere Casals
5-Oct-2016, 15:28
This thread is starting resemble any alt print digital negative thread.

Custom curves...

Yes...

Peter De Smidt
5-Oct-2016, 16:01
Expose enough to get tonal separation in the negative values that relate to darker scene values, and develop enough to get the tonal separation you desire in the rest of the range, keeping in mind the ideal density range of your end use. All the different methods are simply ways of getting to that result.

Drew Wiley
5-Oct-2016, 16:14
Hasn't that been stated a few thousand times before? "Expose for the shadows, develop for the highlights."

Peter De Smidt
5-Oct-2016, 16:19
Sure. Even Mortensen's advice to "Expose for the highlights and develop for the shadows" gets you to the same thing.

Randy Moe
5-Oct-2016, 17:14
The only 'rule' I can remember is overexpose film and underexpose digital.

But don't quote me on that...:)

Pere Casals
6-Oct-2016, 02:44
The only 'rule' I can remember is overexpose film and underexpose digital.

But don't quote me on that...:)

...adding that slide film, a bit like digital...

Leigh
6-Oct-2016, 03:51
Hasn't that been stated a few thousand times before? "Expose for the shadows, develop for the highlights."Even Mortensen's advice to "Expose for the highlights and develop for the shadows" gets you to the same thing.
Sorry, but those are two VERY different approaches. Only the first one works.

If you expect detail in the shadows you MUST expose for it.
If it's not in the latent image it won't be in the final negative. Development has very little effect on shadow detail.

- Leigh

Bill Burk
6-Oct-2016, 06:22
Keep in mind that a densitometer, used with a sensitometer and a few development time tests can provide you with a family of characteristic curves for the film.

The characteristic curves tell you how film responds to light and development in terms of density... so this is just stating the obvious (that those tools and tests can get you this).

I like to think of exposure index as an "overlay" to the family of characteristic curves, drawn in pencil and erased and drawn again if you change your mind... You can move exposure index around. Even the speed points and Delta-X are discussions about the curves and how they are interpreted.

But the curves are just there, they are what they are and can be drawn in ink.

Drew Wiley
6-Oct-2016, 09:11
Plotting families of curves for various developers, developing times, etc, is quite a bit of work. I don't personally do that except for truly fussy applications like
matched color separation negatives, associated control masks, and so forth. But going through this kind of exercise at least once in depth does have one significant advantage: it teaches you how to read published film curves. One you realize how minor differences in curve shape are actually logarithmic and can often translate into truly different looking images, you can select your appropriate films with a lot less intervening headaches. Some people stick with a single film and developer for as long as its own the market. Others of us tailor any number of films and developers to different specific situations. In either event, the data only takes youso far. You gotta shoot/print, shoot/print, shoot/print until it becomes second-nature, spontaneous, just like a well-broken-in pair of gloves.

macandal
21-Jan-2017, 11:54
Suffice it to say if you plan on finding an EI using a Zone System-type test, you can skip that part and simply reduce film speed by 2/3 stop (or round it to either 1/2 stop of 1 stop).So, ASA 100 = EI 64 (as would be in my case since I'm shooting Delta 100)?

macandal
21-Jan-2017, 12:20
Here are the results in my system for other films: Acros (80), Delta 100 (64), HP5+ (200), Tri-x (250).Nice photograph, nice contrast, Peter. What developers use for the films you mention? Especially for Delta 100 (64) [that's what I use]?

Peter De Smidt
21-Jan-2017, 13:36
For the Rialto Beach picture, I used Xtol. For Delta 100, I've used DS-10. I've moved away from Xtol mainly because I don't like to store it for a long time. There are so many terrific developers, such as the Pyrocat formulas, Ryuji Suzuki's developers, Crawley's recipes.... Since I develop film sporadically, I've switched to easy to make developer that I mix up shortly before use. Currently, I'm using DS-2. I recently purchased a flash spot meter and ran a few tests in the studio. If I would've taken the advice of many, I'd have shot Acros at EI 50. In my case that would've underexposed the film by 2/3 of a stop. A few quick tests are all that's needed to hone in on a good exposure and development system for your particular use and requirements.

macandal
21-Jan-2017, 18:45
For Delta 100, I've used DS-10.For Delta 100, I've used DS-10.[/QUOTE]Who makes that or is that one of those home brews?

Thanks.

Peter De Smidt
21-Jan-2017, 20:11
It's a homebrew, but there are a lot of good choices.

macandal
12-Mar-2017, 11:59
So I have another question. Could this method be applied to color films? That is, if I'm shooting Ektar 100, for example, I would shoot it at EI 64 and process according to the developer you're using? What about slide film? Would I do the same?

Thanks.

MultiFormat Shooter
12-Mar-2017, 18:13
So I have another question. Could this method be applied to color films? That is...process according to the developer you're using? What about slide film?

No, color film (both E-6 and C-41) only has one set of developing chemicals, so you cannot pick from several different developers and adjust. In the case of C-41, you can shoot an 18% gray card at several different EIs (with the standardized development time and temperature) and evaluate the negatives on a densitometer. The manufacturer's technical information should give the proper density for a correctly exposed negative shot on a gray card. Then, find the negative that matches this density and set your meter the corresponding EI.

Pere Casals
13-Mar-2017, 03:25
So I have another question. Could this method be applied to color films? That is, if I'm shooting Ektar 100, for example, I would shoot it at EI 64 and process according to the developer you're using? What about slide film? Would I do the same?

Thanks.

Here

http://www.freestylephoto.biz/pdf/product_pdfs/tetenal/TetenalE6_Instructions.pdf

You have instructions for Tetenal E-6.

There are clear instructions for push pull. I see it useful for the case I made a known mistake in the exposure and I want to correct it in the development.

One advice, datasheets should be read with a loupe. Don't miss a single word.

Datasheets are made by skilled technicians and contain very important knowledge. Later you can do it in a different way or even detect mistakes in a datasheet (not common). But always use the loupe. :)

Andy Eads
14-Mar-2017, 11:15
I'm late to this party but a good spot meter makes a passable densitometer. See page 77 here: http://www.largeformatphotography.info/articles/VIDEC.pdf