How specifically do I need to measure CI for alternative processes?

MatthewDunn · May 26, 2021

I am interested in doing some work in Cyanotope and Kallitype using 4x5 from-camera negatives. I don't own a densitometer and was wondering, for those of you doing alt process printing, is a densitometer necessary, or, like in traditional wet printing, you get a sense (after using a particular film stock/developer combination) of what times work to get a contrast level that prints as desired?

I am trying to do things "correctly" (whatever that means in this context) without being overly technical and letting specs get in the way of creativity and art.

ced · May 26, 2021

I think you can get by without & there are lots of articles on the web to help calibration of exposure times.
Visit this site & browse for articles that may be relevant.
http://picto.info/Etech.html

Bill Burk · May 26, 2021

Do you have a Stouffer scale? A common one is the half inch by six inch T2115 with “half stop” intervals.

If you contact print it on film - that’s the basis for finding the contrast of your negatives. A whole can of worms, a densitometer is very helpful here.

If you contact the scale on paper with a picture you immediately see what you got. Compare to the picture you printed. It’s a matter of liking what you see. If the part of the picture is too light or dark and you see a step in the Stouffer scale that you like. Then you know which direction and how much more or less exposure is needed for the next print. Every two steps is a stop. Simple as that.

koraks · May 28, 2021

MatthewDunn said:
you get a sense (after using a particular film stock/developer combination) of what times work to get a contrast level that prints as desired?

This. Just print. It worked in the 19th century, it still works today.

Nicholas Lindan · May 28, 2021

You certainly don't need a densitometer. As suggested - just print. There are too many uncontrolled/uncontrollable variables to take an analytical approach.

Overdevelop the film by 30% or so -- you do want a contrasty negative. Strangely enough pictorial cyanotypes seem to work best with low contrast subjects.

ic-racer · May 28, 2021

How specifically do I need to measure CI for alternative processes?

Traditionally Contrast Index is measured with a transparent overlay.
What I do, is take the first 10 or 11 points after 0.1 and do a linear regression. I started doing this on my Atari computer in the early 1980s and still use that same method in a spreadsheet.

MatthewDunn · May 29, 2021

koraks said:
This. Just print. It worked in the 19th century, it still works today.

Ok, makes sense. My natural inclination is to avoid the technical stuff where I can (while still being safety-conscious and clean/precise about chemistry), so the "just print" route (while understanding I need a denser-than-normal) negative works well for me. Without trying to start a holy war that has been fought 1000x in the past, is there any advantage to a staining developer if I am exclusively printing under UV (i.e no standard silver-printing and no scanning)? I have always been a Tri-X/HP-5 D-76/ID-11, normal agitation kind of guy because it always just looked like the way I wanted so I never needed to wander far. My intuitive sense is to stay the course as the few Pyro HD negs I have developed look perfectly fine, but not demonstrably better than my D-76 negs. Now, having said the above, I am not a caveman and am more than happy to listen to any reasons why I should still consider the Pyro.

Thoughts there?

MatthewDunn · May 29, 2021

Nicholas Lindan said:
You certainly don't need a densitometer. As suggested - just print. There are too many uncontrolled/uncontrollable variables to take an analytical approach.

Overdevelop the film by 30% or so -- you do want a contrasty negative. Strangely enough pictorial cyanotypes seem to work best with low contrast subjects.

Awesome. Thanks much.

koraks · May 29, 2021

MatthewDunn said:
is there any advantage to a staining developer if I am exclusively printing under UV

I've made great negatives for alt prints with both staining and non-staining developers. To be perfectly honest, I don't see much magic in staining developers. Lately I've been using instant mytol (xtol clone) for anything b&w and it also works just fine for making bullet proof negatives for salt prints. I'd suggest simply starting with what you have on hand and moving on only if you experience problems.

MatthewDunn · May 29, 2021

koraks said:
I've made great negatives for alt prints with both staining and non-staining developers. To be perfectly honest, I don't see much magic in staining developers.

Yeah, to be clear, I've used Pyrocat HD in glycol (I think that is probably the safest way to use it), it just never seemed like the results were so different to my eye that it merited a change from plain old D-76. That other people use it and see the effects they are talking about, I don't doubt. Just have never much seen it in the (admittedly very) limited amount of time I have been using it.

koraks · May 29, 2021

Well, if I look at them side by side, it's easy to see the stain in pyro developed negatives. But if that necessarily makes a better image, especially for contact printing, is a different matter.

Vaughn · May 29, 2021

I use PryocatHD (not in glycol). It is relatively inexpensive, easy to store and use -- tho I buy the kit from B&S to keep things simple for me. And I have also used Dektol and Ilford's Universal PQ developer with excellent results to get the contrast up to where my processes like it (carbon printing and pt/pd). With the pt/pd I print without contrast agents, and my negatives for carbon printing are about a DR of 3, give or take (I sent a few negs off to someone to read, out of curiosity). My pyro negs are among some of my best.

But I have always just worked with my film and processing to match the process visually. I have done a little work with step wedges in workshops, but do not use them regularily. I have 'wasted' a bunch of time along the way trying to figure things out, but I have enjoyed it and have discovered things that I might have missed otherwise.

Until one has worked with a process long enough to discover its secrets (good and bad), subtle changes such as staining vs non-staining developers may be difficult to see.

MatthewDunn · May 29, 2021

Vaughn said:
Until one has worked with a process long enough to discover its secrets (good and bad), subtle changes such as staining vs non-staining developers may be difficult to see.

This is the essence of my point - as someone beginning with alt-processes (kallitype with an intent to move on to pt/pd), I know that I do not know enough about the materials or the process to start randomly switching out variables. Maybe just a case of seeking out confirmation for me previously-held beliefs, but was just hoping to hear what it seems most people are saying, which is "pick one set of materials and print a LOT with that one set of materials."

Vaughn · May 29, 2021

The biggest issue I find with such water-color based processes is finding a good paper, then buying enough of it to insure a few years printing before the paper disappears or changes. COT320 and HPR solved that, except for the expense part.

MatthewDunn · May 29, 2021

Vaughn said:
The biggest issue I find with such water-color based processes is finding a good paper, then buying enough of it to insure a few years printing before the paper disappears or changes. COT320 and HPR solved that, except for the expense part.

Ok, as I am really just starting, I bought some Arches Platine. I know enough watercolorists to know that Arches has a decent reputation in that community and the team at Bostick & Sullivan indicated it was fine for Kallitype. Not inexpensive, but I've learned (somewhat) to stop hassling over dollars and cents when it comes to this kind of thing.

MatthewDunn · May 29, 2021

Vaughn said:
COT320 and HPR..

with those being the two other obvious choices...

Craig75 · May 29, 2021

Just take the same scene twice. Develop one normally. Give other one an extra 30% (or whatever). Print them. Compare side by side. Done.

DMJ · May 29, 2021

Suggested development adjustments for Pt/Pd (should be the same for kallitypes but might be different for cyanotypes?) in Pradip Malde's "Platinotype"

Subject Brightness Range | Development time | Zone system Notation
2 to 5 stops | P + 30% | N+
6 to 7 stops | P | N
8 to 10 stops | P - 25% | N-

P = N + 70%

Vaughn · May 29, 2021

MatthewDunn said:
Ok, as I am really just starting, I bought some Arches Platine...

I have a some. The various surfaces of the papers come into play as well as the texture or feel of the paper, and how easy it is too work with. The thin translucent papers can be beautifully used. Its a trap!!!!!!!

MatthewDunn · May 29, 2021

Vaughn said:
The thin translucent papers can be beautifully used.

I would love to see an actual pt/pd print on Tosha Washi paper, for instance. Until then, things like this will have to suffice:

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