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peter brooks
11-Sep-2021, 12:30
Just wondering what went wrong here... Last batch of negs came out very thin.

Fomapan 100 - film holders left loaded for quite a while (but not kept in excessively hot conditions).

Rodinal - old as the hills (but has been fine).

Usual dilution, temperature and time, Jobo 3006 used many time before and processing is usually fine. Different lenses / shutters used so it's unlikely to be a shutter speed issue.

So the question is, what is the likely cause - can Fomapan 100 sensitivity 'fade' (once out of chilled conditions), or can Rodinal suddenly lose it's potency? Or maybe both? :)

Thanks!

Alan9940
11-Sep-2021, 14:27
I've used a lot of Foma 100 over the years, but I can't recall storing any for more than about 3-4 months at room temp. Never had any complaints after that length of storage. Whenever I've had unexpected thin negs, it's always been the developer has gone off; though I always thought Rodinal could be passed down to your great grandkids! ;)

Greg
11-Sep-2021, 14:47
Rodinal used at high dilutions can be easy to screw up... I had been using Rodinal at 1:50 with excellent repeatable results. Then started using a larger JOBO drum which took more chemistry. Did the math in my head and without realizing it was diluting Rodinal to either 1:100 or 1:200. Fortunately only underdeveloped a few sheets of 11x14 film. From then on I created a dilution chart which hangs on my darkroom wall instead of using my head or even a pencil.

peter brooks
12-Sep-2021, 02:27
Thanks both. I think the Rodinal was to blame, I've ordered a fresh bottle.

I like Fomapan for its cost-effectiveness (a marketing man once told me never to use the word 'cheap') but not at all for its defects - I'm on the second box of 5x7, I had to stop using the first because of random stuff / blebs on the film. Kind of russian (or czech, rather) roulette. Obviously a bad batch, not what you want.

(Yes, I have a spreadsheet printout of quantities at various dilutions pinned to the wall - I don't trust myself to work it out on the fly :) )

esearing
12-Sep-2021, 05:06
FYI you can bleach and redevelop the negatives and get a little more out of them, but it also tends to increase the contrast. Use a staining re-developer like pyrocat HD . You can do it in room light in a tray. Test with a less important negative.

Tin Can
12-Sep-2021, 05:31
Even very thin negs scan pretty good

Try it ON a real scanner

peter brooks
14-Sep-2021, 12:36
FYI you can bleach and redevelop the negatives and get a little more out of them, but it also tends to increase the contrast. Use a staining re-developer like pyrocat HD . You can do it in room light in a tray. Test with a less important negative.

That's good to know, luckily all the shots were not far away, so I can easily take them again. A pain, but not a disaster.


Even very thin negs scan pretty good

Try it ON a real scanner

They did scan - kind of - lots more garbage visible, and even the fogging on the underside of the V750's platen (out-gassing? I cleaned it years ago and will have to do it again), which I've never seen in a scan before.

Thanks both anyway!

Luis-F-S
14-Sep-2021, 13:24
There are usually two reasons why negatives may be thin: you under exposed or you under developed. The second includes using ancient developers and other stupidities. L

Richard Wasserman
14-Sep-2021, 15:40
You can also under expose AND under develop for the best of both worlds (ask me how I know). You might try selenium toning the negatives—you should gain about a stop of density and contrast. I suggest KRST 1:1 for 1 minute, although it will go to completion and stop working so your timing doesn't need to be too precise.

Jim Noel
15-Sep-2021, 06:06
Selenium will primarily increase the density of the highlights thus a slight increase in contrast. Bleach and redevelop in sepia toner will increase teh shadow denisty about 2x what happens with selenium.,

Richard Wasserman
15-Sep-2021, 06:35
Thanks Jim that's good to know. I've never tried the bleach and redevelopment technique—I've read about it, but never tried it. I'll keep it in mind.

jnantz
15-Sep-2021, 07:13
Peter

I am not a Rodinalite, but I follow trends ... I read recently that people had trouble with Rodinal and HC110 not lasting as long as they were used to. Don't ask me where I read it I can't exactly place the thread or site (terrible memory these days). Good luck figuring out the root of your problem. John

Jim Noel
15-Sep-2021, 10:56
I have no proof, but my belief is that modern "Rodinal" must have a slightly different formula than the original. Luckily I still have a few bottles of the original in Orange Agfa boxes and the botles labeled in a similar fashion. The formulae I have seen perpetrated as exact copies all differ n some manner.