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- Nov 16, 2004
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(1)The density with D316 was very slightly higher than Xtol 1+1.You did a great job in formulating this concentrate,the pH was near enough spot on and you managed to dissolve a lot of AA by using the metaborate first.I appreciate your doing this, as it's always good to have reviewers check one's work. Some questions:
* How do the densities of the two negatives compare? My goal was twice XTOL's dev-time, and I'm wondering how close I got for a conventional grain film.
* Could you compare grain by viewing the neg's directly with a loupe? I've found that even a dedicated film-scanner as good as my Nikon Coolscan IV ED does not reliably show grain due to focus-variation, so I trust direct viewing in a loupe or microscope more. Hmm, I guess a couple of carefully-focused extreme enlargements (projecting onto the floor?) would also clearly show the grain-difference.
* I notice that the area under the bumper is darker in the Xtol-scan, indicating a difference in black-point and/or gamma in the scans. How did you set these in your scanning software?
My goal is to get XTOL's grain in a concentrate, and I'll keep hammering at it. Feedback like this is good.
Mark Overton
(...) and you managed to dissolve a lot of AA by using the metaborate first.
(3)Good spot. But I might get cast into the outer darkness for answering that on APUG.
(4)I did wonder if you could make a very strong concentrate that would give a working solution closer in composition to Xtol ,which working solution could be re-useable by throwing out and replenishing 70ml each time. But already the solubility limits are approached.
Mark, It's been a long time and I can't find my recipe (...)
Does it make it worse because the iron bound by it is still or even more chemically active (like it is supposed to be in Ammonium-Ferric-EDTA) ? Or are there other effects I have not thought/learned about?
Would Dequest 2010 be better? I have a possible source for it here in Europe (Tronds knows about this).
That said, there is an excellent book written in Japanese language, more updated than Haist and James combined, and written by mostly Fuji, Konica, and University of Chiba people. It's probably still the latest single book that is comprehensive.
You are not by any chance talking about this book?
Mark;
K2SO3 should equal Na2SO3 in solvent effects. It should also buffer pretty much the same so have you checked the pH of the working solution?
As for Potassium salts, the problem is that they exhaust the fixer more rapidly if one has a sloppy work flow. Too much K ion in a fix will poison it! Bill and I have discussed it and with a good running water rinse or a good fresh stop after the developer or using a one shot fix, there should be no problem.
Of course, K salts are more expensive in the US.
PE
after developing a 1.5 frame-long strip in 100 ml of that formula, the developer was a little yellow. Its pH was 8.04 afterwards (8.02 before). Might this indicate a capacity-problem? I'm concerned that 250 ml might not have enough capacity for a 36-shot roll.
- It works unusually cleanly when combined with TEA. Potassium sulfite + TEA appears to act as a mild restrainer, giving low fog even when overdeveloped. The toe seems to be flatter, so there's a slight loss of darkest shadow-detail (and probably speed). I did not get this restraining effect when these alkalis were used separately.
- As I mentioned before, PS accelerates development of phenidone+ascorbic and dimezoneS+ascorbic. After some fine-tuning, I find I need about a third less developer to get the same activity.
Theres not much of a cost-difference between potassium sulfite and sodium sulfite. I took PhotoFormulary's prices for 1 liter and 1 pound, and got 20 cents versus 16 cents per roll. PS is more convenient, since it comes in a concentrate, but don't forget PE's warning about washing it out in the stop-bath to avoid killing the fixer.
Ryuji: I tried developing again using the light yellow developer, and it worked fine, keeping most (all?) of its activity. But after the 2nd strip, the developer was a light orange! I hold the film-strip in the graduate using a non-stainless steel clip; might iron from that be upsetting the chemistry?
Incidentally, in the past, it was said that potassium thiosulfate is a poor fixing agent compared to sodium, and this is probably why a rumor of potassium salt in fix ruins the bath. In reality, theres no reason to go beyond ammonium or sodium salt anyway, and I could not detect change in clearing time by adding a reasonable amount of potassium sulfite to an ammonium thiosulfate fixing bath. Im not going to say the rumor was incorrect, but I might say irrelevant.
I finally got finer grain than XTOL! By a small margin, but finer when carefully compared in a pair of 22X loupes. I only tested it with TMY-2, and this one-liter formula is merely a baseline for further work:
On TMY-2, the grain is slightly less clumpy and less stringy than XTOL's, and thus appears more like fine sand in my 22X loupes. Grain also appears slightly finer than XTOL in monotone areas. As mentioned earlier, the toe is slightly lower than XTOL, but the difference is small enough that most people probably wouldn't notice. I'll use this formula as a baseline for more experiments, including (1) using sodium sulfite instead because that's what most people have, (2) reducing sulfite and boosting TEA to reduce chemistry, (3) making a PG-based concentrate out of it, (4) general fine tuning and testing, and (5) other films.
Potassium Sulfite, 45% solution ... 80 ml
Ascorbic acid ........................... 4.5 g
TEA ....................................... 2.7 g (yes, grams; = 2.4 ml)
Dimezone S ............................. 0.067 g
Target pH=8.0. Starting dev-time is twice undiluted-XTOL's time.
Here are full-resolution crops of neg-scans of TMY-2 in XTOL (left) and this test-developer (right):
-
In both cases, the scanner was manually focused on the "V". Although the scanner can't pick up individual grains, you can see there's less noise in the second scan due to finer grain. Also, I want to take some grain-photos through a microscope and post them, but it'll take some time to get a microscope-setup working.
Mark Overton
Nice work.
How are you using Xtol? Stock? 1:1, or even more dilute? Replenished?
Do you print these to see what they do when projected?
Thomas,
I'm using Xtol stock (1+0) one-shot, so that's 6.5 minutes at 20C. I wanted XTOL to show off the finest grain it could. Everything is done at 20C with identically exposed strips.
No printing yet. I have a list of changes to that formula I want to try -- substituting chemicals, changing quantities, dropping pH more, etc. I'd like to see if I can do better, or perhaps do just as well and use less chemistry. In addition, the experiments provide a "feel for the environment" -- an intuition of what effects changes will have. But it takes patience: Once cycle of mix developer/temper bath/dev strip/fix/clean up takes me about an hour. I'm careful and accurate, which is good for repeatability, but such care eats time.
I want to get a densitometer. I'm tired of matching densities by eye, and a densitometer will let me create absolute and relative density-curves, which will clearly reveal loss/gain of speed, contrast/CI, highlight-compression, and anything else relating to tone-levels.
As an aside, I notice that the test-developer image (2nd image) is a bit darker than XTOL's image. Dense areas of the neg's had matching densities, judging by eye through two pieces of paper with a hole punched in each. The difference might be due to auto-exposure in the scanner, which I can't control.
Mark Overton
Just FYI, the Formulary in MT have excellent densitometers for sale. They are unlisted. You can get them with a special order. I have one and it works for both reflection and transmission. PE
Not sure where you're located, but I'd be glad to read the densities for you if you need help with this. If you want to buy one, used models can sometimes be had for relatively low prices on eBay etc. I bought my Heiland from Versalab (it does both transmission and reflection) and have found it to be both reliable and easy to use. It was expensive though. I was going through a phase where I did massive amounts of film/developer/ZS testing so I felt it was worth the investment at the time. Now, not so sure!Regarding step wedges, I bought mine directly from Stouffer some years ago. Not sure who else you can buy them from.
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