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Thread: Chemical age -- metol

  1. #11

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    Re: Chemical age -- metol

    Hi, Doremus. I'm still a bit stumped, after another couple of tests, but still working on it. I just mixed a fresh batch of developer, in case I did make a mistake in the last batch. Not sure how I could have miscounted 4 teaspoons of Metol but I've done more foolish things before.

    I think I will pull an old neg for which I have printing data recorded and see how that fares; I probably have a proof print of as well as contact sheet. I just processed another neg in the fresh developer, using my same test set-up illuminated and exposed to give me Zones 0-VIII with most included. Development time was 11 min 1:1 @ 68, 25% more than my previous 9-minute N, and I also increased the agitation to every 30 seconds. That's already more than should be necessary; I'm quietly fending off feelings of utter incompetence. My meter seems to be on target , as tested in sunlight this morning, and I haven't been throwing my thermometer at cement walls or baking it in a hot oven... The latest neg may have gotten me a good Zone VIII. I'll know as soon as it dries. I'm using my spot meter as a densitometer.

    The new LED color is certainly less blue. I had to replace the first LED panel after getting some wires in the "prototype" caught in the enlarger superstructure. The new one requires closer balance of green and blue, although I tested the last one with a borrowed Stouffer and this one with my own, new one, just arrived. But I doubt the old one was faded, for various reasons. I feel as if I have been swimming in a sea of changing variables since I returned to photography.

    Stay tuned.
    Philip Ulanowsky

    Sine scientia ars nihil est. (Without science/knowledge, art is nothing.)
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  2. #12
    Tin Can's Avatar
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    Re: Chemical age -- metol

    Your OLD head had a channel out?

    and you compensated...

    good luck




    I mean that
    Tin Can

  3. #13

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    Re: Chemical age -- metol

    Quote Originally Posted by mdarnton View Post
    I have metol from about 35 years ago that I still use and it's fine. It's even picked up a light brown cast through time, but doesn't seem to matter. D23 is generally a flat developer anyway, which is why I use it.
    Same here. I got a 5 pound jar way back when. Still as good as new.
    Last edited by xkaes; 27-Nov-2022 at 10:12.

  4. #14

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    Re: Chemical age -- metol

    I’m betting on something with the DIY blue/green LED head as they are not necessarily that simple to design/make. That would seem to be the most likely place to look, but that’s just a guess really as I had a hard time following the end-to-end procedure/test methodology which led to the unexpected contrast results. I really doubt it’s the D-23, which can stand a fair bit of slop (amounts, metol quality, sulfite quality) before failing materially. If Philip has access to a pH meter, just to “cross the Ts and dot the Is”, D-23 should be around pH 8.

  5. #15

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    Re: Chemical age -- metol

    Well, I have found part of the issue, but not all. By projecting the Stouffer scale, rather than contact printing it, my green-blue balance has changed significantly, even though I have been using diffusion enlarging for many years and my Componon glass is immaculate. I dialed back the green to near where it was with the previous panel, to get 7 steps of gray (not including the two closest to black and white, respectively) in a ~5x7. print. The balance is now 150G, 255B, with R150. I suspect the imbalance of G-B is due to the green tendency of LEDs generally and the less-than-ideal blue from the cheap 16x16 LED panel -- I have noted that those using single green and blue LEDs specify Royal Blue as opposed to other blue LEDs as necessary to achieve a true Gr. 5.

    Exactly how much of the problem my previous setting represented, I have not measured precisely. Another bizarre anomaly popped up last night, in which the 12 minute neg had less density than the one developed just before it for 11 -- same dev batch, same temp, same agitation. The only variable I can think of was slight temp loss during the course of development, but that would not account for the difference. Sometimes I wonder if I've gone senile. Anyway, I have another 12-min neg, carefully temp-controlled, drying now, so I'll soon see what that yields. I'm agitating every 30 sec now, something I have never done since I started developing film in 1968; always on the minute when not using my rotating tank (small batch 4x5 is now in my Stearman tank). I'll be so glad when this episode is over!
    Philip Ulanowsky

    Sine scientia ars nihil est. (Without science/knowledge, art is nothing.)
    www.imagesinsilver.art
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  6. #16

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    Re: Chemical age -- metol

    I breathe a public sigh of relief, that the latest neg is right on target, though I'm still surprised that I needed 33% more development plus additional agitation to get it. Now I'll have to adjust and confirm the rest of my times, at least a "spot check" to indicate that the new times are in line with this. With luck, I'll get that done today and be done with all this testing, for now at least.

    As always, thanks to the valuable contributions of others in this thread. Just to know that someone else is ready to assist, helps to get through such confusing moments.
    Philip Ulanowsky

    Sine scientia ars nihil est. (Without science/knowledge, art is nothing.)
    www.imagesinsilver.art
    https://www.flickr.com/photos/156933346@N07/

  7. #17

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    Re: Chemical age -- metol

    Just a note to say that I'll sleep better tonight: N+1 and N-1 followed suit with the N adjustment, so, besides a tweak to be made here or there, I'm feel myself back on solid ground. Phew! I told that to my wife tonight, and she replied, "It's an illusion." (Forty-five years of marriage, for that?)

    Now I can get back to figuring out times with DD23, which is how this all got started to begin with, when my N development looked like N-2. Perhaps this will go a bit more easily. I won't repeat my reasons for trying it, given in my OP. I'll post when I have some useful results.
    Philip Ulanowsky

    Sine scientia ars nihil est. (Without science/knowledge, art is nothing.)
    www.imagesinsilver.art
    https://www.flickr.com/photos/156933346@N07/

  8. #18

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    Re: Chemical age -- metol

    Ulophot in not sure when you talk about balancing blue and green, you expect to be able to somehow copy ratios from e.g. old-style cold light sources over to LED or that a 1:1 ratio in your particular LED setup means the same as a 1:1 ratio in any other kind of light source. If so, forget about it, because it doesnt work that way. Unless you are measuring intensities on an absolute scale like uW/cm2, color ratios are completely idiosyncratic to the light source used. For instance, you use LED and so do I, but I can guarantee you that my 1:1 blue:green ratio prints totally different from yours and that's not only due to differences in peak wavelength of the LEDs used.
    So I'm not sure if you're trying to use your blue/green ratio in your LED head as some kind of benchmark for your film development, but if so, keep in mind you're chasing ghosts (and irrelevant ones at that!)

  9. #19

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    Re: Chemical age -- metol

    Hi, koraks. Thanks for your comments. Allow me clarify my thinking and procedures here.

    If one uses a 211 or 212 bulb in a condenser enlarger, as I did for years, the unfiltered light gives the same, or virtually the same, contrast print as yielded by the same source with a #2 filter. At least, that was my experience, with both Kodak and Ilford filters years ago. When I got a coldlight, I took the advice to put 40Y in the path to get back to Grade 2 from the bluer, more contrasty light. However, after 13 years away from enlarging, I returned about 5 years ago, and, after some experimentation and consideration, decided to use the cold head without the 40Y, just the Ilford filters. My tests at the time indicated it was about Gr. 2 1/2 unfiltered, and I tended toward gentle negs anyway.

    As indicated above, the LED head, which uses a cheap 16x16 RGB panel, was an open question when I began using it. I eventually borrowed a friend's Stouffer 21-step scale and used it for contact prints so that I could dial in an unfiiltered Gr 2. It end up at around 150G, 240 B. Through various "adventures" between then and recently, including replacing the LED panel -- long story short -- I got my own Stouffer and made projection prints this time, retesting to get the same contrast whether I used no filter or a Gr. 2 Ilford one (this time, 160G, 255B), and found that with a Gr. 2 coming from the head, my Normal film development was yielding a neg with grossly inadequate density. My exposure was just slightly less than it should have been for the test (bellows comp), but the 9 min development was landing Zone X on Zone VIII. A new set of tests has brought my N development to 11 1/2 or 12 minutes, with appropriate additions to my N-1 and N+1, which is as far as I have gotten.

    Thus, all I have been doing with the balance adjustment is striving for a resulting Gr. 2 proximate to a densitometric standard. That gives me an anchor for my film development as well as for making contrast adjustments in printing.
    Philip Ulanowsky

    Sine scientia ars nihil est. (Without science/knowledge, art is nothing.)
    www.imagesinsilver.art
    https://www.flickr.com/photos/156933346@N07/

  10. #20

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    Re: Chemical age -- metol

    Quote Originally Posted by Ulophot View Post
    As indicated above, the LED head, which uses a cheap 16x16 RGB panel, was an open question when I began using it. I eventually borrowed a friend's Stouffer 21-step scale and used it for contact prints so that I could dial in an unfiiltered Gr 2. It end up at around 150G, 240 B. Through various "adventures" between then and recently, including replacing the LED panel -- long story short -- I got my own Stouffer and made projection prints this time, retesting to get the same contrast whether I used no filter or a Gr. 2 Ilford one (this time, 160G, 255B), and found that with a Gr. 2 coming from the head, my Normal film development was yielding a neg with grossly inadequate density. My exposure was just slightly less than it should have been for the test (bellows comp), but the 9 min development was landing Zone X on Zone VIII. A new set of tests has brought my N development to 11 1/2 or 12 minutes, with appropriate additions to my N-1 and N+1, which is as far as I have gotten.
    Alright, thanks for explaining, although I'm not sure I can follow. I don't mind if you want to keep it at this without answering my questions, which are more out of curiosity - although also some concern if your LED source is doing what you think it may be doing.


    >retesting to get the same contrast whether I used no filter or a Gr. 2 Ilford one (this time, 160G, 255B)
    Does this mean you need a different blue/green ratio since replacing the led panel?
    Is it correct you're using a grade 2 filter in combination with your led panel? If so, why?

    > with a Gr. 2 coming from the head, my Normal film development was yielding a neg with grossly inadequate density
    Inadequate density, or insufficient gamma?

    If your light is 'grade 2', then it will be so regardless of the negative used. If your negatives that printed with the desired tonal scale on grade 2 don't print the same with a new light source, it means the new light source isn't "putting out grade 2" so to speak.
    If you mean that your negatives have insufficient overall density, i.e. your Zone X ends up VIII but your zones I through III all drop into dmax, then you don't have a problem with your negative, but you're just overexposing the print. Dial back light output, stop down etc.

    I have a feeling you're trying to fix a misunderstanding about how a LED light source works by changing negative development, which would be tricky proposition to say the least. But perhaps it's just my misunderstanding your explanation that needs fixing

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