Pyrocat Tests and Some Disappointment?

Hello all - Been lurking a few months now (very educational!) but wanted to share some recent film testing and get some opinions on the results, apologies for my lengthy blather:

I've just recently started processing my own film again after a 15 year hiatus, and instinctively reached for my old standby HC-110 to process 4x5 TMX. But to add interest and after reading many glowing reports on this forum I decided to give Pyrocat-HD a try. I've been really surprised (and a little disappointed?) by the results, and wanted some extra eyes to spot any issues in my process / results / expectations. Excuse the boring subject matter and somewhat flat scan, I scanned to retrieve all the information from the negative, putting the white and black points just beyond the end of the histogram:

HC-110 (Dilution B @ 68F 7.5m, TMX EI 100) : http://gottanukesomethin.com/photo/d...ei100-7-5m.jpg
PyrocatHD (1:1:100 @ 68F, 16m, TMX EI 50) : http://gottanukesomethin.com/photo/d...-1-100-16m.jpg
PyrocatHD (1:1:100 @ 68F, 16m, TMX EI 100) : http://gottanukesomethin.com/photo/d...-1-100-16m.jpg

Processing:
All done single-sheet in homemade PVC tubes with ball valves as light-traps. I can see no fogging / streaking / scratching from this process.
Agitate continuously for first minute, then 10 seconds / minute thereafter. Standard dilution indicator stop and kodafix.

So all three negatives look fairly reasonable, nothing blown out or terribly underdeveloped, the 50 EI is preferable of the two Pyrocat negs I think, but my concern is the highlights: the HC-110 negative shows good seperation and local contrast in the top of the binder pages (which I placed in the neighborhood of Zone VIII), but the Pyrocat negatives seem to have flattened out and gotten a bit murky and undetailed. I guess I can see how this would be a pleasing effect in many situations, but the loss of local contrast seems a bit dicey to me and makes me nervous about Pyrocat for general use. Maybe I'm falling for magic bullet syndrome, but I was surprised to be overall happier with the HC-110 (in this admittedly non-real-world test).

So, do these negatives look like I should expect for Pyrocat HD? Is there something flawed in my process or my testing, or should I accept my results and keep on with my nice cheap yellow cough syrup? Would another film show the PHD magic?

Is the goal to make prints traditionally or to scan?

A quick response would be to try developing for a longer time with the pyrocat.

You haven't mentioned how you metered the photos or printed/scanned them.

All things being equal, wouldn't we expect to see roughly 1 f/stop difference in the high values, when comparing two images identically developed but exposed 1 stop differently ?

For example: if they are all under-exposed and under-developed, and then corrected in scanning or in the image editor - then can we draw a reasonable conclusion ?

Peter: Scanning as a final product, at least for the foreseeable future. Develop for a longer time with the same agitation? My instinct is that I would end up blocking the highlights even further, but I'm willing to accept being wrong about that...

Ken: Metered the small gray square above the Ilford box as Zone V, Top of the binder fell around Zone VIII. EI 50 shot corrected back to reasonable values via the scanner. EI 100 shots were f11@1/2 sec, the EI 50 was f11@1 second. I am definitely willing to rescan later tonight to eliminate the correction as I'd love to feel definitive about these results... The EI 50 exposure was from my (perhaps mistaken?) impression that I would lose some film speed with the Pyro, so I decided to cover that base and over-expose one negative as a test. If that is a poor assumption (re: film speed loss) then we can compare just the two @ EI 100.

sgutterman, how does the stain look?

I'm no expert but I would want to make the comparison with the Grey Card adjusted to the same value in PS.

Andrew: Noticeable sepia color, does not appear to be any non-image stain but this is coming from a voice of zero experience. Other than highlight detail I *think* the negatives look healthy.

(And thanks to all replying I appreciate the input!)

sgutterman,

Since you gave the EI 100 sheets identical exposures, The differences in exposure can reasonably be attributed to the different developers, provided both sheets were developed to the same contrast, which It doesn't appear they were. The PCHD sheet looks a little more developed than the HC110 sheet. This small variation in development shouldn't have much effect on the film speed, but it does affect the rendition of the highlights. On my screen, the PCHD sheet looks better overall than the HC110 sheet, which seems to have a haze/fog over the image, but this could be attributed to the difference in contrast. If you want your PCHD developed film to look more like your HC110 film, try decreasing development of your PCHD film. On the other hand, if you like your HC110 film, why not stick with HC110?

Try what Tony suggests. Match your gray card to its proper value in photoshop. Adjust your black/white points. All three images are a bit dark. Also, as a side note, if you are just scanning and working digitally, a thin negative scans best. Really thin.

When judging film speed and development time:

In the world of the wet darkroom (enlarging or contact printing) we can decrease the number of variables by using a standard printing paper and standard developer. We expose and develop for a standard time: just enough to print through the film base. This approach is popular in the Zone System.

In the world of sensitometry, we further decrease the number of variables by getting rid of printing altogether: we use a transmission densitometer to measure film density directly. This is the method used by film manufacturers and experts in exposure and development. It's also the method used in BTZS. After all, film speed changes with development time. It's a moving target. Film doesn't have just 1 speed. That's why Minor White (Zone System) recommended that we increase or decrease exposure according to how we intend to contract or expand contrast via development.

On the other hand, complexity is increased as soon as we we add a scanner and an image editor to the equation - and a monitor, printer, paper, etc. :cool:

I suggest you have a look at this article on Pyrocat HD, paying particular attention to the way in which different films and development times are discussed. Don't read anything: just look at the charts. Page four is particularly revealing: it shows how the contrastiness of different films is affected by changes in development time, with just one developer. It's very easy to see how they differ.

A few graphs and numbers can save us a lot of time and materials, and rescue us from the tangle of speculation, hearsay, and anecdotal evidence.

Jay: Because I'm looking for magic bullets here! In seriousness I made this post basically to make sure I'm not missing something important about Pyrocat. E.g. if everyone responded "Um yeah that's what TMX in Pyrocat looks like" or conversely "Dear lord you've read the directions wrong the actual dilution is '...'!" then I didn't want to throw good materials after bad chasing down what would be an obvious problem to someone more experienced. Re: contrast, this is a totally appropriate question but I lack a densitometer and don't have a good way to quantify.

I'm definitely interested in continuing to experiment after all I think I have about 470ml remaining of both my pyrocat solutions and a few more exposures of this magnificently composed still-life. I agree that overdevelopment is a possibility, perhaps trimming back to 12 minutes and trying again? I generally have been (many years ago now) happy with results from HC-110, but always looking for some little improvement where I can get it!

Andrew: good suggestions, I'll muck with these a bit on the digital side.

Ken: Thanks for the link, reading up now. And agreed on complexity, I was nervous making this post since as I wrote it up I was forced to reckon with all the glaring holes in my scientific method. I should spring for a densitomoter but it's a tough thing to spend money on. Of course I'll probably end up spending the cost in film and chemistry testing this to death....Reading!

Intellectual curiosity is not a bad thing, in my book. learning about chemistry and sensitometry is fun, and sometimes it can even be put to practical use! Good luck, and have fun!

It's the best thing! :) Thanks for all the suggestions, gang, I'll update if I come up with something worthwhile.

Quote:

---

Originally Posted by sgutterman

I should spring for a densitomoter but it's a tough thing to spend money on. Of course I'll probably end up spending the cost in film and chemistry testing this to death....Reading!

---

You don't have to buy one, unless you plan to test a lot of film or digital negatives.

One thing I've learned by looking over the data which accompanies the purchase of the BTZS "Plotter" program (a number of films, in a number of developers, at various dilutions, for various times) is that they all look fairly similar. One gets the same impression looking through Ansel Adams' books, where it becomes evident that over the decades he used a wide variety of films.

Some film/developer combinations are better than others of course - they have more linear response to light and changes development time - or better effective film speed. Some are easier to mix, have longer shelf-life, or are cheaper, but those are secondary features. Where they really differ most (in my humble opinion) is in terms of grain, spectral response, apparent sharpness, acutance, reciprocity, etc. When it comes to Large Format, many of those are irrelevant, and we can often make good use of just about anything... once we've tested it.

You might find it very helpful to choose one film/developer combination and do a film test with Fred Newman at the View Camera Store. Then you'll know what you've got: independent of scanner, monitor, software, calibration tools, photo editors, Gamma settings, color spaces, ink sets, room color, etc. Hey, the digital world is supposed to make things easy :rolleyes:

I'd try to make the best prints from each and then compare. That is how Loyd Jones did it.

Just stick with what you know, you dont have to drink the cool aid.

Quote:

---

Originally Posted by mdm

Just stick with what you know, you dont have to drink the cool aid.

---

An absolutely meaningless statement, considering none of us is born "knowing" any developers, and not much of anything else, either. Those of us with some modicum of intellectual curiosity actively go about seeking that we don't know so we might. But the small minded are always suspicious of the more generously endowed, and I suppose it makes you feel better to equate inquisitiveness with an irrational surrender of free will, even if it's more like the exact opposite.

Quote:

---

Originally Posted by Dakotah Jackson

Pyrocat HD is known for being very good for highlight separation without blowing them out.

---

Yeah I suppose that's at the heart of why this has me so puzzled, I expected the exact opposite of my results. Everyone waxes on about PCHD's highlight rendering so seeing blocked highlights was a surprise. I'll consider finding a printer although it might be a tall order. If only I was still a teenager with a basement darkroom... In the meantime I'll try cutting back on development time and see what happens.

And re: sticking with what I know... I understand what you mean, but experimentation is fun and enriching! And besides which what I know is 15 years old and these days possibly up for cancellation. My favorite film used to be tech pan, after all.

Just stick with what you know, you dont have to drink the cool aid.

Quote:

---

Originally Posted by Jay DeFehr

... the small minded are always suspicious of the more generously endowed, and I suppose it makes you feel better to equate inquisitiveness with an irrational surrender of free will, even if it's more like the exact opposite.

---

Perhaps MDM meant that sometimes it's helpful to work within a set of limitations, that running off in too many directions at once can be counter-productive. By analogy, some people experiment by shooting with only one lens, or photographing only one subject.

Sticking with a single film/developer combination - and doing what it takes to get it to work - can amount to a form testing in its own right.

Tmax film is very sensitive to changes in development, so you may not have to cut back as far as you'd expect. I'd cut back till it started affecting shadow detail slightly, then increase agitation to 5s/30s. I'm not a zone system expert; I do use pyrocat-hd, pmk, and tmax 400.

Quote:

---

Originally Posted by Ken Lee

Just stick with what you know, you dont have to drink the cool aid.



Perhaps MDM meant that sometimes it's helpful to work within a set of limitations, that running off in too many directions at once can be counter-productive. By analogy, some people experiment by shooting with only one lens, or photographing only one subject.

Sticking with a single film/developer combination - and doing what it takes to get it to work - can amount to a form testing in its own right.

---

He might have meant a lot of things, but he wrote one thing. The OP made his own intentions very clear, and it's unreasonable to assume he doesn't realize he has the option of not experimenting with another developer. MDM's use of the cliche, "drink the cool aid" is difficult to interpret a anything but snide, and adds nothing of substance to the discussion, just as the increasing number of posts in response to his add nothing of substance, and to which I'm guilty of contributing. I should learn to ignore trolls.

What I meant was that you dont have to use pyrocat just because its supposed to be good, be your own judge of what is good. Many of the best pictures are made by people who just do what they do, eg Jim Kitchen, Maris, Austin who gets what the lab gives him, John Sexton. I use Pyrocat M, sometimes I wish I didnt but thats what I use and I am not changing because its cheap and I have plenty.

MDM, I don't think your in any position to be handing out any sort of advice negative or otherwise especially when the work you display on your web site is taken into consideration!

Quote:

---

Originally Posted by mdm

What I meant was that you dont have to use pyrocat just because its supposed to be good, be your own judge of what is good. Many of the best pictures are made by people who just do what they do, eg Jim Kitchen, Maris, Austin who gets what the lab gives him, John Sexton. I use Pyrocat M, sometimes I wish I didnt but thats what I use and I am not changing because its cheap and I have plenty.

---

Right - the goal here is not darkroom acrobatics for their own sake; and it's not to get down with a popular solution; it's developing a set of methods that give me results I'm pleased with and that I feel steeped in and comfortable with, so I can go and confidently take pictures out in the world with a good idea of what's going to happen over the kitchen sink later on. Given how many people use and love PCHD I felt it was worth the testing I'm currently doing.

If I don't get this sorted out satisfactorily I hereby promise I won't keep using Pyrocat. I'll switch to caffenol and post rambling diatribes about the inherent superiority of Folger's T-Crystal Structure as it affects transient...shadow...rendition...on the toe of the reciprocity...density transmission feedback frequency.

Quote:

---

Originally Posted by kev curry

MDM, I don't think your in any position to be handing out any sort of advice negative or otherwise especially when the work you display on your web site is taken into consideration!

---

Where's his website?

More Kool-Aid anyone?

It is great to experiment, but if one experiments aimlessly the results will likely be ambiguous at best, at worst useless and without meaning. Speaking here with considerable experience on the subject!!

Sandy

Quote:

---

Originally Posted by sanking

More Kool-Aid anyone?

---

Giggle

Quote:

---

Originally Posted by Wally

Where's his website?

---

...looks like he's gotten rid of it!

Going back to the original question...

1) The lighting may have been arbitrary: compared to the other objects in the scene, we don't know how dark that jacket was - or should look. Nor do we know how deep the shadows were. It's best to shoot a target with a known contrast range. Were there 7 stops difference between the deepest shadows and lightest paper ? Were there 10 stops ? Perhaps, if the lighting was soft, there were only 5 stops. Unless we know what we're trying to reproduce, we can't judge whether we've been successful.

2) Because with film we need to "expose for the shadow values and develop for the highlights", this test is, in some ways, backwards. If we want to evaluate the effect of an extra stop of exposure, we would look to the shadows, not the highlights. We can always adjust the highlights by adjusting developing time. What we really want to determine, is how much exposure is enough to give accurate low values.

3) The target image contains only a modest selection of subject values or zones. A gray card is a good start, but it would be better to have all the tones present if possible. An ideal way to do this, is shooting a step-wedge. Another is to meter some of the other items in the scene and identify them. At the very least, have some human flesh-tones in the scene, because the eye is very good at judging faces and flesh tones. Unless we know exactly how things should look, how can we tell how far off they are ? Placing the gray card on Zone V, where is the yellow sticky pad ? How many stops difference was there, at the scene, when you metered it ? That sort of thing.

The nice thing about BTZS testing is that you shoot a step wedge with 5 sheets of film, and develop each sheet for a different time. Based on that, you get all the information you need. (You can always make a sample shot as you did here, just to make sure that theory and practice are aligned, but unless your arithmetic is off, the results should be the same.) It's actually rather brilliant.

Going back to the article cited earlier, have a look at page 4. The charts on that page describe exactly how much contrast you get by developing those different films, for different times. For example, see Figure 24, which shows Kodak TMY developed in Pyrocat HD 2:2:100. The numbers on the bottom (X-axis) are developing time, and the numbers on the right (Y-axis) indicate Gradient, another name for contrast. The longer we develop the film, the higher the contrast. That makes sense.

I have taken the liberty of showing the graph here. I hope that's OK.

http://www.kenleegallery.com/images/forum/BTZSTMY.png

For Contrast Index, 0.5 is the "normal" value, which corresponds to N in the Zone System. So according to that chart, we get normal development at around 7 minutes. That test result alone, is worth its weight in gold. We get N+1 at around 10 minutes, N+2 at 12, etc... Ka-ching !

Another thing you see, is that compared to some of the other films, this one is very linear with respect to developing time: the line is very straight, which means that changes in developing time affect contrast quite evenly and predictably. While the T-grained films have a reputation for being "finicky", that's because people who are careless in their technique, get different results if they screw up - but that's highly desirable in a film/developer combination: it lets us precisely control things to get the most beauty out of our materials.

And Beauty is, as they say, its own reward :cool:

By comparison, here's part of a test that Fred Newman made for me a few weeks ago, of Ilford HP5+ developed in D-23 1:1 (not divided D-23).

http://www.kenleegallery.com/images/...TZSHP5D-23.png

Note that this is a more diluted developer - and D-23 has a reputation as being low-energy - so the contrast range is much lower - but how much lower ? There's no guess work here.

To get a normal Contrast Index of 0.5, we need to develop for 10 minutes. Also note that even after developing for 16 minutes, we still haven't reached N+2 expansion. This film/developer combination is probably great for a sunny day at the beach, but not for bland subject matter.

On the other hand, with this film/developer combination, N-2 development happens at around 5 min 15 seconds.

So not only do we know that this is a "lower contrast film/developer combination", we know exactly how low, and how long to develop it to get the contrast we want.

There's no guesswork involved. Instead of relying on someone's well-meaning but vague advice (Person A: "I've been souping Plus-X in X-Tol 1:8 for the last decade. I really like it." Person B: "You gotta try Tri-X in PMK-XYZ at 3:2:1000. Nothing beats it") we get unambiguous facts we can really use, and a common language with which we can easily compare and categorize film/developer combinations.

This isn't the whole story, though. We know that different film/developer combinations give different effective film speeds. But which one gives which speed ? Shall we rely on friendly advice ? ("Try pushing FP4+ to ISO 8000 and develop it in Nescafe - you gotta see it to believe it") :cool:

Quote:

---

Originally Posted by sgutterman

If I don't get this sorted out satisfactorily I hereby promise I won't keep using Pyrocat. I'll switch to caffenol and post rambling diatribes about the inherent superiority of Folger's T-Crystal Structure as it affects transient...shadow...rendition...on the toe of the reciprocity...density transmission feedback frequency.

---

That sounds awesome. Make sure you label the axies of your graphs in your report on this. And the US folgers might be different from the EU folgers.... And how the stain affects VC printing.

Quote:

---

Originally Posted by Ken Lee

You don't have to buy one, unless you plan to test a lot of film or digital negatives.

One thing I've learned by looking over the data which accompanies the purchase of the BTZS "Plotter" program (a number of films, in a number of developers, at various dilutions, for various times) is that they all look fairly similar. One gets the same impression looking through Ansel Adams' books, where it becomes evident that over the decades he used a wide variety of films.

Some film/developer combinations are better than others of course - they have more linear response to light and changes development time - or better effective film speed. Some are easier to mix, have longer shelf-life, or are cheaper, but those are secondary features. Where they really differ most (in my humble opinion) is in terms of grain, spectral response, apparent sharpness, acutance, reciprocity, etc. When it comes to Large Format, many of those are irrelevant, and we can often make good use of just about anything... once we've tested it.

You might find it very helpful to choose one film/developer combination and do a film test with Fred Newman at the View Camera Store. Then you'll know what you've got: independent of scanner, monitor, software, calibration tools, photo editors, Gamma settings, color spaces, ink sets, room color, etc. Hey, the digital world is supposed to make things easy :rolleyes:

---

The late Phil Davis used to do a demonstration at his workshops designed to show that choice of developer and developing methodology makes a much bigger difference in the look of the negative and ultimately the print than the brand or type of film used. Sorry I don't remember the details of exactly what he did but I think he did this in most of his workshops (I attended two and he did the same demo in both), maybe someone else does.

I second your suggestion of using The View Camera Store to do testing. I've made the same suggestion here many times. They do it faster, easier, and likely for less money while providing more information than one spends doing their own testing. That said, doing one's own testing is an excellent learning tool.

I'm not aware that "the digital world is supposed to make things easy." In my experience scanning and printing digitally makes things harder (but potentially better).

Quote:

---

Originally Posted by jp498

Make sure you label the axes of your graphs in your report on this.

---

And I thank Ken Lee for filling in that blank left in Sandy's article on the Unblinking Eye.

Particularly: The meaning of contrast index, in terms of normal values, for people who did not read the BTZS book before reading the article on Pyrocat.

Rick "who actually had to look at the Wikipedia article on sensitometry to understand the log-exposure axis--every 0.3 is a stop" Denney

To be clear, a contrast index of 0.5 is normal for printing with Silver Gelatin.

On the BTZS charts, the Contrast Index is listed as G with a bar over it, which means Average Gradient. It's the average slope of the contrast curve. In other words, given a certain amount of exposure, how dense the negative becomes. When contrast is low, even a lot of exposure gives little density, and the curve is rather flat: its slope or gradient is low. When contrast his high, even a little exposure results in a lot of density: the slope of the curve is rather steep, IE the gradient is high.

Actually, Sandy's article has a table - at the top of the same page to which I have referred - which shows the recommended Contrast Index for different media.

http://www.kenleegallery.com/images/...trastIndex.png

That table is another piece of information which is worth its weight in gold, as is the statement "Most processes have means to control contrast but it is good practice to always start with the best negative possible for the process."

Some feedback...
Visit pyrocat-hd.com for the suggested development times.
16 minutes could be too much, depending on agitation. The negative should look "thin".
TMX is a great film.
You should look at the pyro developers/negatives as a "variable contrast developer/negative". Scan them in color and pick the channel closest to the target contrast.

Quote:

---

Originally Posted by rdenney

And I thank Ken Lee for filling in that blank left in Sandy's article on the Unblinking Eye.

Particularly: The meaning of contrast index, in terms of normal values, for people who did not read the BTZS book before reading the article on Pyrocat.

---

The graphs on page 1 and 3 of the article, are different: they show Exposure on the X-axis (horizontal), and Density on the Y-axis (vertical). It's interesting to see that the stain density follows the visual density, only it's steeper - and given that UV-sensitive processes need steeper (contrastier) negatives than Silver, the prints we make on either media will have similar appearance, with no need for correction. As Dakotah rightly points out, it's all about the prints.

Quote:

---

Originally Posted by Ken Lee

The graphs on page 1 and 3 of the article, are different: they show Exposure on the Y-axis (horizontal), and Density on the X-axis (vertical). It's interesting to see that the stain density follows the visual density, only it's steeper - and given that UV-sensitive processes need steeper (contrastier) negatives than Silver, the prints we make on either media will have similar appearance, with no need for correction. As Dakotah rightly points out, it's all about the prints.

---

Yes, the dual purpose character of pyro stained developers is a real plus for photographers who print with their in-camera negatives in both silver and pt/pd (and other UV sensitive processes). This has been known for a long time. Edward Weston comments on it in one of his day books, as I recall with reference to a negative he made while in Mexico.

Sandy

Quote:

---

Originally Posted by onnect17

Some feedback...
Visit pyrocat-hd.com for the suggested development times.
16 minutes could be too much, depending on agitation. The negative should look "thin".
TMX is a great film.
You should look at the pyro developers/negatives as a "variable contrast developer/negative". Scan them in color and pick the channel closest to the target contrast.

---

I think this is probably related to my issue. I'm too used to looking for 'thick' negatives, which especially given that I am restricted to scanning for the time being, is a habit worth breaking, as is eye-balling it. I haven't any time for more testing since I posted, but I have been reading and glad this sparked an informative (for me) discussion. Particularly thankful to Ken for the very thorough posts, thanks for taking the time. And Sandy thank you for chiming in, hope you don't take any of this as a slight on your work... Hopefully I'll have some new negatives in the next day or four to at least comment on in lieu of doing some more rigorous testing.