PDA

View Full Version : Film Test Results



Tony Flora
3-Sep-2008, 08:31
I need some helping interpreting my film speed test. I have attached 3 images from the N (normal) development roll of 120 film (Delta 100). The first image is Zone V, the second Zone IV, and the third Zone III. I think I made a couple mistakes and I may need to reshoot this. Mainly because the light was not even and I should have probably kept everything in focus. Anyway perhaps the more experienced here can help me decipher this. I metered from the grey card that is in the image and developed normally. I also developed the same exposures on 2 separate rolls at N-1 and N+1. Did I make a mistake by metering off of the grey card? Should I have metered for zone III or some other zone? The one thing I have learned from this so far is the affect of N-1 and N+1.... that is good stuff. Thanks.

Ron Marshall
3-Sep-2008, 09:01
For a film speed test you should shoot a blank wall or grey card. Don't consider plus or minus development until you have established your personal EI for your equipment and process.

See the following link:

http://www.jerryo.com/formula/z_speedtest.html

Tony Flora
3-Sep-2008, 09:24
Ron,
are you saying I should have filled the lens with the grey card? There is one in the scene I shot as a reference. Also, this is the normal development, I also did N+1 and N-1, but that is not included here and was just done to get a feel for what can be done. Thanks for link.

John Cahill
3-Sep-2008, 10:14
Ron,
are you saying I should have filled the lens with the grey card? There is one in the scene I shot as a reference. Also, this is the normal development, I also did N+1 and N-1, but that is not included here and was just done to get a feel for what can be done. Thanks for link.

Yes. Fill the frame, and make sure the grey card is completely out of focus as well.

Wade D
3-Sep-2008, 15:57
For a film speed test you should shoot a blank wall or grey card. Don't consider plus or minus development until you have established your personal EI for your equipment and process.

See the following link:

http://www.jerryo.com/formula/z_speedtest.html
Good info. I'm just getting ready to jump back into 4x5 after many years.

Anupam
3-Sep-2008, 16:23
For a film test speed there is no reason the gray card has to be out of focus, so long as there wasn't enough bellows draw for that to be a factor.

willwilson
4-Sep-2008, 12:14
Basically what you are trying to do is find out how much developing time it takes to build a certain density level at a certain metered zone. This will vary depending on what zone you are testing as the higher zones (V thru XV+) build density for a longer period of time during development than the lower zones (I, II, III, IV). You definitely need even lighting and you would be better off just shooting the gray card, but do not shoot it with an extension longer than the focal length of your lens that would put you into macro compensation.

Steve Simmons has a good article on this:
http://www.viewcamera.com/pdf/2006/VC_Getting%20Started.pdf

Also I have a few good links on my links page:
http://willwilson.com/articles.html

Ken Lee
4-Sep-2008, 14:29
Another way, is to shoot a real scene, in daylight, with people in it, and with real subjects that are in light and shadow.

If you can't find a "real" person, you can always use... yourself. Here's a test shot (http://www.kenleegallery.com/images/tech/tmypc200.jpg) I did when trying TMAX at ISO 200, in PyroCat HD. I tripped the shutter with a long bulb release.

As you can see, its easy to figure out which film speed/developer combination to use, when you know right away how things are going to work in "real-world" situations. You can tell right away, whether the result will "feel like light", which to me is a tangible and worthy goal. It's what I was taught a long while back, and I still like the approach.

Tossing in some black and grey fabrics in sun and shade, as well as a dark cloth, film holder slide, pumpkin, porcelain pot, green leaves, black socks, and a plastic bottle, help lend credence to the final result.

Like so many others, I found that TMY works best for me at 1/2 the stated film speed - just as Tri-X was, back in 1971 when I first tested it in HC-110, getting the same results as Fred and Ansel. One would certainly hope so.

It is reassuring to discover that my agitation is normal, my thermometer is calibrated, and my water is... not too contaminated. :rolleyes:

ic-racer
4-Sep-2008, 14:31
The simplest way to determine your EI is to meter a uniform target and expose it to Zone I at varying exposure indexes.

Process the film at any guess at what your development time for "N" might be (your Zone I density won't change that much if your development time is not 'correct.').

Look at the resulting negatives and choose the one that shows the target to be 0.1 log denser than the clear film base. (That's 1/3 of a stop).

How to you make the determination of 0.1??

1) Use a densitometer (best)
2) Use your exposure meter and meter through the negatives and pick the one that blocks light 1/3 of a stop more than a clear frame
3) Send your negative strips to someone who has a densitometer and have them e-mail you the results.
4) Guess. Sandwich two pieces of clear film base together and match that to the target negatives.

Peter De Smidt
4-Sep-2008, 16:18
Ic-racer gives good advice, with the caveat that your Zone I density be at least .1 above film base plus fog. Personally, I prefer the shadow separation of Zone I being .15 to .2 above fb+f. After you determine your film speed, i.e. how much exposure to get a proper zone I density, you then need to determine your development times. An easy way to do this is to set your meter for the speed your first test achieved. You then exposure a gray card and place it on zone VIII. Use the same development that you used for the film speed test, and read the density. If you have a condensor enlarger, a good target is 1.2 above fb+f. With a diffusion enlarger, zone VIII at 1.3 above fb+f is a better measure. If you're densities aren't close to what I listed, you can then adjust development time to get them in the ball park. Btw., I'd be happy to read negative densities for you. PM me if you want me to do so.

ic-racer
4-Sep-2008, 16:46
Ic-racer gives good advice, with the caveat that your Zone I density be at least .1 above film base plus fog.

Good point! The 0.1 test (and the ISO and ASA tests) gives you the thinnest negative of optimum quality with, unfortunately, very little underexposure latitude.

Tony Flora
13-Sep-2008, 18:47
So I finally got in my order for more Delta 100 and did a film test as suggested in the link Ron put up. I don't have a densimeter so I am kind of eye-balling it. Is it just me or does minus 5 (zone 0) look too light? it's definitely not pure black. I am thinking I will experiment some at an ISO of 200 and see how I like the results and adjust as necessary. That would bring zone 0 up to zone 1. Am I on the right track?

venchka
13-Sep-2008, 19:42
I followed the link. I read most of it. My problem with that test is he says to to make 1 stop increments in exposure. That seems too coarse to me.

Hard to say on a monitor. They are all different. How did you conduct the test? I would assume that you used ISO ratings from about 50 to 160 or maybe 200. What developer-time-temperature did you use? How much time for each exposure of the print?

From reading Steve Simmons various articles and book, the grey scale you posted should be the one where you find the time, f-stop and development to produce black with your enlarger. The next step is to make 5-6 negatives at 1/3 stop increments. The negative that produces one shade lighter than black at the same time in your enlarger is your film speed.

Read this article and try Steve's method.

http://www.viewcamera.com/pdf/2006/VC_Getting%20Started.pdf (http://www.viewcamera.com/pdf/2006/VC_Getting%20Started.pdf)

Tony Flora
13-Sep-2008, 20:11
I followed the shooting directions exactly as described. I stopped down the aperture to adjust exposure and developed in DD-X for 12 min at 68 degrees. Agitation was done for 10 seconds, once every minute in a Paterson Tank. The grey scale I posted is all of the scans from the negatives I shot for the test. I just combined them in Photoshop to make it easier to compare the results. They start at FB+F and go up to a Zone V meter reading. At this point I think I just need to determine where Zone 1 is. I don't haver a densimeter so I am trying to determine visually, what my EI will be going forward.

Tony Flora
13-Sep-2008, 20:22
I don't know if it matters but I took the meter reading with a Pentax digital spot and confirmed the reading with my Nikon D200. My true concern is that Zone 0 (minus 5) is not black. I am thinking that it should be closer to FB+F but I am still trying to figure out if that is a correct assumption.

ic-racer
13-Sep-2008, 21:39
I don't know if it matters but I took the meter reading with a Pentax digital spot and confirmed the reading with my Nikon D200. My true concern is that Zone 0 (minus 5) is not black. I am thinking that it should be closer to FB+F but I am still trying to figure out if that is a correct assumption.

Depending on the toe characteristics of the film, the zone 0 may have some slight density in the print above black. I wouldn't worry about it.

Honestly I can't judge that zone I exposure on the computer monitor. Did you try putting that zone I negative over your meter? If it drops 1/3 of a stop from film base (0.1log) I'd go with that.

venchka
13-Sep-2008, 21:51
What ic-racer said. I would work in 1/3 stop increments to find Zone I. The rest will take care of itself. Then you need to do a similar developing time test to find Zone VII, Viii or IX.

But that's just me.

ic-racer, Thanks for the negative over the meter tip.

ic-racer
13-Sep-2008, 22:14
ic-racer, Thanks for the negative over the meter tip.

Years ago when I was in graduate school, I did all my film tests with a home-made rig. I had a spot meter held with a clamp, and a desk lamp suspended over it. I ran my film strips over the meter aperture and converted the EV to log for graphing.
I did not have a sensitometer and a step-wedge, so I did 21 in-camera exposures to get the complete curve. The most difficult part was keeping track of the exposures. The bulk loaded film did not have frame numbers that matched the frame numbers of the camera. With all those zone 0 and below exposures, it was always very easy to get lost as to which frame matched the exposure notes.

What a hassle. Now I have 2 sensitometers and 2 densitometers...

Tony Flora
14-Sep-2008, 03:36
Did you try putting that zone I negative over your meter? If it drops 1/3 of a stop from film base (0.1log) I'd go with that.


Yes I did. Minus 5 was 1/3 over FB+F. So that means Minus 5 is Zone 1 and the ISO should be 200. Is that correct?

Thanks for the help.

Tony

John Bowen
14-Sep-2008, 03:53
Tony,

Pehaps it is mentioned somewhere in this thread and I missed it....you are trying to eliminate as many variables as possible. One of those factors with a LF camera is bellows extension. You should focus your camera on infinity first, then point the camera at the single toned card (preferably a black card in open shade for Zone I) and fill the frame with the card. DO NOT REFOCUS THE CAMERA.

You are trying to come up with a Zone I exposure that would mimmick real life. If your Zone I exposure is 1/400 @ f90, you probably need a darker card and less light :-) How do you get a Zone I Exposure of 1/400 @ f90??? By shooting a white card in bright sunlight then stopping down until a Zone VIII object is a Zone I exposure.

Good luck and welcome back to LF photography

ic-racer
14-Sep-2008, 07:56
Yes I did. Minus 5 was 1/3 over FB+F. So that means Minus 5 is Zone 1 and the ISO should be 200. Is that correct?

Thanks for the help.

Tony

That all seems correct.

Most people think of ISO as a fixed property of the film, so your 'exposure index' would be 200, but everyone knows what you mean.

Now that you have your EI, one way to get your development is to shoot a Zone VIII at EI 200. Then print that (at your min exposure for max black) with part of the paper covered. If it is just off-white your film development should be good for printing most scenes on multigrade paper.

Tony Flora
14-Sep-2008, 09:06
IC and others thanks for all the help. I don't have an enlarger just yet, I am undecided about wether or not to wet print or get an inkjet. I really want to sell off all of the digital stuff and go full analog but that is another subject for another day.

venchka
6-Oct-2008, 11:24
2) Use your exposure meter and meter through the negatives and pick the one that blocks light 1/3 of a stop more than a clear frame



OK, I did that. My reading for ISO 250 is 1/3 stop on my Gossen Luna-Pro. With a digital meter (Minolta Auto Meter IV), I get 0.3 for the ISO 250 negative and 0.4 for the ISO 200 negative. I guess my speed for HP5+ in Xtol is ISO 250.

Can I do the same/similar thing reading negatives with an exposure meter to find my developing time relative to Zone VIII? How many stops above fb+f or the Zone I exposure on the exposure meter should I be looking for?

Thanks for all your help.