Ilfochrome Color Saturation
I'm still having this problem since they started making the P3.5 kit that replaced the P30 kit.
With all the paper types that I was using before the switch, with the correct exposure/development times, the color is about 30-40 percent weaker, and the contrast is 20-30 percent softer.
Does anyone know how dev and bleach dilution strength affects the color saturation/contrast?
IDK about the developer, but the bleach is a process that goes to completion. If it does not work properly, the dmin values go up and become gray. Therefore, if the whites are white, silver is gone, bleaching worked as desired and something else is probably wrong. Of course, the catalyst in the bleach has some effect on dye contrast and intensity, but if it is at the wrong level, then all of the silver is not properly bleached.
It is probably either the paper or developer based on what I know of the chemistry of the process.
The developer must get good silver contrast and must produce some degree of interlayer effects to enhance color. The paper must have enough contrast in the emulsions and enough iodide in them to enforce this effect. If either one of these fail, then the process fails.
Too much silver, or overdevelopment for example will lower contrast, dmax and color saturation. A developer with low activity would do the same, but would leave a somewhat elevated dmin behind. So it looks like a low silver coating, or an overactive developer.
Of course, they may be using new dyes with lower purity. This would decrease the cost. They also might have reduced the level of the old dyes to reduce cost. Both moves would give a more muted color, but the latter method would also reduce the depth of blacks.
Just a bunch of guesses. I'm about to do some dye bleach experiments on my first steps to making a multilayer color print material as a test. So, I've been studying the chemistry again.
The current chems, P3.5, work perfect with only one of the original paper types. It's called CPS1K, the most expensive of course...
But with the other types, there's my problem.
With tests on those types all of the grey tonal scale is 10-20 % weaker, but the color sat is reduced 30-40 %.
So as an experiment, I will dilute the dev strength with h2o by the 30 % and see what happens.
The paper is still fresh and was working fine with the original P30 formula.
If it's the acid in the dev, what can I do about it?
Diluting the developer is a good start. If it works, but highlights are muddy, then increase development times in increments until they clear up. That will suggest that it is the developer. But, in a real sense, it is that all of the papers are not a good match for the new process due to some change and variation among the papers.
It might be that you need an entirely different developer though for the misbehaving papers, and dilution might not work. It could even make the problem worse. You might need a high contrast developer like D-19 or something akin to that to increase silver contrast.
Can you tell me where you get your Ilfochrome chemistry?
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Thanks again PE!, I'll keep trying and post what happens.
Dan, the last order was from Rainer Photographic, but they went OOB.
Soon I will start searching for a new supplier.
I'll post who they are.
Originally Posted by davetravis
I have some 4x5 Velvia that I'm dying to print, but the only Ilfochrome chemistry I can find is at B&H and they won't ship it. I've heard that Freestyle photo will be carrying it soon, but I'm still waiting.
As I mentioned, I am working on making my first color coating. Along with that I will be recreating the dye bleach bath that I used to use.
I'm willing to post the formula here, and you can try it to see if (how) it works. I cannot guarantee anything but if I can come up with a hand mix, then all you need is a fix and developer. For all I know, D19 can work. I've heard that people use it.
PE is THE MAN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Back to the original problem: Same new chemistry formula behaving differently on different paper types, that used to all behave the same with the original formula.
I did a controlled experiment, using a perfect print made with new formula as the standard.
Used the same sized print, same filtration, same processor time/temp.
Diluted the Dev by 30%, the Blx by 40%.
Left the fixer the same.
Adjusted the paper exposure accordingly.
Eureka! Normal contrast and ultra rich color!
I can now use up the over $1k of other paper in inventory.
(ok, I'm easily excitable)
Last edited by davetravis; 11-13-2007 at 05:06 PM. Click to view previous post history.
I am so glad it worked. Sometimes things pan out just the way you predict.
I would guess that in the long run you won't have to dilute the bleach as it goes to completion. It was probably the developer. But, I cannot guarantee that is the case.