That comparison suggests that the two films react differently to different developers. I'm surprised at the contrast To be sure, there should be 4 comparisons. You should have another Xtol cmparison, 166.
Good news: A second roll of TMY2 batch 0167 worked great! I changed two things:
* All non-developer liquids (presoak, stop, fix, wash) were at the higher temperature of 22-24C (instead of 18-19C).
* I mixed fresh TF-4 fixer.
Unlike the last try, the following occurred as expected:
* Fixer poured out magenta (instead of clear).
* Wash-water poured out magenta.
* Film had no residual magenta colouration.
* Density-curve is perfect, as shown below:
The first symptom that changed is the colouration of the fixer, so perhaps old TF-4 fixer fixes not only the image but also the magenta dye? The old fixer was clear (not yellow) and had a clearing-time of 60 seconds, so I thought it was fine. But it had 51 rolls run thru it, and the instructions said it is good for 28. Oops. Could old fixer partly bleach the silver image? It's hard to imagine why densities would be low.
'ello mate. You are using British or Canadian spelling of COLOR Mark.
So, there is an unknown variable in these tests that cause a problem! Before you go on, you must identify that variable. Find out if it affects all films or just this one batch etc....
I would keep everything at the same temp. Look into getting a Jobo processor or Jobo tempering bath. They make it really easy to getting temps all the same.
Originally Posted by albada
I'd suggest using a two-bath fixing scheme. The oldest fixer bath gets used first and then the freshest fixer bath second. That way you do all the heavy fixing with the first bath, and then the second bath can clean up the last bits of unfixed silver.
I think a two bath fixer scheme would even out variations in fixer life-cycle.
First, Kirk: Thanks for the suggestion about a two-bath method of fixing. For me, fixer costs almost nothing compared to rolls of film, so I'll probably simply replace my fixer much more often.
Originally Posted by Photo Engineer
@PE: Does my personality have color or colour? The apug spell-checker red-marks American spellings as wrong, and since British English is the international standard, I figured I should spell things that way.
There's another variable I neglected to mention: The plastic lid for the SS tanks had a orange-brownish residue on them which I noticed after the bad TMY rolls, and which I cleaned off. My beaker dedicated solely to fixer also has a slight orange colour-cast, so the TF-4 fixer leaves a bit of insoluble residue. But the amount is so small, and the prewash removed some magenta dye (unlike later steps) that I doubt this residue was the cause of failures. Note that I wash film with the lid on, so this residue survived all that washing.
I discarded the old fixer, so I can't reverse that change.
Today, I tried a roll of TMY2 with cool liquids for everything but developer. It made no difference (everything worked fine).
Listing the changes:
* Insoluble residue - exceedingly unlikely to affect anything.
* Temperature - had no effect.
* Old TF-4 fixer - that must be the cause!
I suspect that well-used TF-4 accumulates a chemical that prevents dissolution of the magenta dye. In addition, it seems to do some bleaching. "Well-used" meant 51 rolls in 1.5 litres, including about 20 test-strips which would dilute it a little.
Your opinions about this? I wish I'd kept the old fixer.
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At this time, I have no clue. Sorry.
D316 works fine with all films made by Ilford, Kodak and Fuji.
I've crunched all the data and am finishing some retesting. The only real surprise is that Delta 3200 takes 25 minutes to develop. I'll post all the dev-times in not too long.
Fuji Acros has an interesting density-curve. Here are curves from two rolls with different dev-times:
When most films start shouldering off in extreme highlights, Acros shifts into overdrive and ramps back up after X=0.3. As a result, the curve has a small swale from X=-0.3 to X=0.6. The upward slope of the swale won't affect photos unless they're badly overexposed, but I thought I'd point out this odd behaviour. BTW, these two curves are shifted horizontally a little because I've been tweaking my methods.
Your Acros curves are consistent with the repeated testing I've done with that film in a variety of developers. Finally someone has confirmed my results!!!
It is something that differentiates it (in addition to reciprocity behaviour) significantly from TMX and Delta. I have consistently found contrast to be highest in the extreme highlight area of the curve. In ZS parlance, contrast typically increases slightly around Zone IX, and stays that way until it shoulders rather abruptly - as opposed to the far more gradual shouldering exhibited by nearly every other current general purpose medium or high speed film. As a result with normal development the highlights develop to much higher densities than its TMX and Delta counterparts.
I posted comparative curves for Acros, TMX and Delta a few years back to point this out and at the time I recall PE saying it was indeed an odd behaviour for a general purpose film (and would make it an interesting dupe film). My view is neither positive or negative. A curve like this can have its uses - particularly if one wants to use extreme contraction procedures without obliterating highlight detail.
Looks like Fuji is having trouble blending emulsions too. That is the usual result from a minor mismatch in either speed or contrast.
You did your tests "a few years back", so surely Fuji would have discovered this by now. Perhaps it has a small enough effect on most people that they haven't bothered to fix it.
Originally Posted by Michael R 1974
Interesting. In my ignorance of film-design, I'll speculate that Fuji's low speed emulsion in Acros needs to be a little faster and less contrasty. Am I close?
Originally Posted by Photo Engineer
Kodak's TMY2 is more worrisome. Here are curves from batches 0166 and 0167:
All were developed in D316 for 12 minutes. The green line is batch 0166 -- it's so straight that it's almost ideal. The red line is batch 0167 with old fixer, which has an obvious break. What bothers me is the black line, which is batch 0167 with new fixer: It is sagging with its inflection at the same point as the red line. That tells me the emulsion issue is still there.
That would mean there are *two* problems:
- Poor blending of emulsions.
- Old fixer that messed up the magenta dye and made the neg thin for some reason. It occurred to me that each time I fix, the fixer pours out magenta, and I'm therefore putting magenta chemicals into the fixer for each roll. So I'm not surprised that after a while, chemical-buildup in the fixer affected the film.
BTW, my tests of batch 0167 shows that a pre-wash increases density, as was true of batch 0166. I have no clue why.