Dark patches on negatives; SP 445

[smeylan]

Hi all, I am trying to debug some issues with my setup (started large format about a month ago)

I am finding that I am getting unexpected, splotchy variations in density in my negatives that vary from negative to negative. In the first picture, the top right has a splotch, there's a vertical gradation at the second pine tree, and the left edge is too light. In the 2nd, there are 4-5 vertical light splotches in the right side of the sky. It's not in the same place in the two, so I don't think it's a light leak in the camera or the tank, and the splotches make me think it has to do with my dev process.

206717

206718

Both are Delta 100, 1/8s, f/45 processed from the same batch with an SP-445, no pre-wash, 1+4 DD-X for 10:30 (agitated by rocking, but not inverting, every 10s for the first 2 minutes, then once a minute), stop bath (ilfostop 1+19) for 1:00, fixed for 5:00 (Ilford rapid fixer, 1+4), and washed for 20 minutes.

Is this the result of insufficient or excessive agitation? Insufficiently mixed chemicals? I am spending lockdown at my partner's house in CA so I don't have a darkroom to compare to tray processing.

[ethanfg]

I would say that it’s insufficient agitation. I would try inverting the tank. I normally do a couple of inversions once per minute, but you can vary this to taste. To avoid leaks, squeeze the tank body as you tighten the cap. This will create negative pressure in the tank helping keep the liquid in. It may help to shoot some frames of a blank wall, then you’ll have no problem seeing if the issue is still there.

Ethan

[Alan9940]

I agree that it looks like insufficient agitation. I invert my SP-445 and have never seen anything like this on my negs. If inversion doesn't totally resolve the issue, I'd suggest a pre-rinse, too. Yeah, I know Ilford doesn't recommend it for their films, but I've done one with all films for 40+ years and never found a good reason not to.

[Mick Fagan]

I had a call from a friend last year about processing in an SP 445 tank, she was having an issue or two and I seem to remember one of her negatives looked slightly like yours do.

She came over to my place and we developed some film in my SP 445 and hers. Her technique was similar to yours, she didn't invert; I do.

After the first run of two sheets in each tank, mine and hers, we compared films. Hers were a little bit like yours, whereas mine had very even development.

My technique is to fill the tank with approximately 465ml, ensuring there is enough room for some air to allow for the chemistry to flow. Close the tops, bang the tank a couple of times to help remove any air bubbles attached to the film, then do four inversions over the first minute. From then on I do 3 inversions every 30 seconds, timing the last inversion at the end of a 10 second cycle. Meaning that at 30 seconds I invert three times, with the last inversion completed at 40 seconds.

The lady in question then did another run using my technique, the same chemistry was used. Her negatives were certainly slightly more contrasty than her first run, but there was definitely evenness of development compared to her first run. I am of the understanding she now pretty much uses my technique, probably with a minor difference or two and is quite satisfied with her negatives.

We did not use a pre-soak. In fact, I cannot remember ever doing a pre-soak of films in over 60 years of developing film.

Mick.

[Tobias Key]

I had similar problems when I first started developing with a combi tank. I worked out you have to give adequate agitation but ensure that each individual agitation is not too violent. What you are aiming to do is change the part of the developer in contact with the emulsion, without causing the developer to surge around any fittings in the developing tank. I had problems with uneven development so I added inversions to 'cure' it. The extra agitations actually made things worse which went against what I thought was accepted wisdom. I ruined a few too many sheets going down this rabbit hole. In the end I settled upon giving 3 inversions that lasted about 3 seconds each every 60 seconds. So invert, wait for the developer to settle, then invert again. The problem with most developer recipes is that they express agitation in time. If you are told to give 10 seconds agitation does that mean three inversions or five? I have settled on counting inversions which I perform in a consistent manner and found that works better for me.

Although you are not inverting the tank be open to the idea that you might be rocking the tank too suddenly and the developer is surging around the negative holder. It could save you some grief!

[Bob Salomon]

I had similar problems when I first started developing with a combi tank. I worked out you have to give adequate agitation but ensure that each individual agitation is not too violent. What you are aiming to do is change the part of the developer in contact with the emulsion, without causing the developer to surge around any fittings in the developing tank. I had problems with uneven development so I added inversions to 'cure' it. The extra agitations actually made things worse which went against what I thought was accepted wisdom. I ruined a few too many sheets going down this rabbit hole. In the end I settled upon giving 3 inversions that lasted about 3 seconds each every 60 seconds. So invert, wait for the developer to settle, then invert again. The problem with most developer recipes is that they express agitation in time. If you are told to give 10 seconds agitation does that mean three inversions or five? I have settled on counting inversions which I perform in a consistent manner and found that works better for me.

Although you are not inverting the tank be open to the idea that you might be rocking the tank too suddenly and the developer is surging around the negative holder. It could save you some grief!

The instructions that I wrote for the CombiPlan T was to use the chemistry called for on the inside of the lid. Rap tank on hard surface to dislodge any air bells and invert the tank till the chemistry stops running, then invert back till it again stops running and repeat for the recommended inversion time from the developer manufacturer.

[smeylan]

Thanks everyone for the suggestions and comments!

I tried increasing agitation to 4 1s inversion cycles every 30s per the SP-445 instructions. The results were odd -- generally better for 3 of the 4 sheets (no artifacts; better contrast) but very strong artifacts of the tank holder on the 4th sheet (below)

Next I will try Mick Fagan's advice of gentler inversion with the protocol of "invert three times, with the last inversion completed at 40 seconds." I would be appreciative if anyone has thought on whether it is agitation during development or stop that is messing me up.

206749

[Kiwi7475]

Thanks everyone for the suggestions and comments!

I tried increasing agitation to 4 1s inversion cycles every 30s per the SP-445 instructions. The results were odd -- generally better for 3 of the 4 sheets (no artifacts; better contrast) but very strong artifacts of the tank holder on the 4th sheet (below)

Next I will try Mick Fagan's advice of gentler inversion with the protocol of "invert three times, with the last inversion completed at 40 seconds." I would be appreciative if anyone has thought on whether it is agitation during development or stop that is messing me up.

206749

Is it possible you put that 4th one emulsion side looking into the holder? That’s the only way I can think of to cause that issue.

[smeylan]

@Kiwi7475, yes it's possible, and I found another example on the board here with the same error. First time in 32 sheets!

One question re: the SP 445 -- it is still leaking all over when I try to invert. I am wetting the O-ring, using 450 ml solution, squeezing / raising the water level to get a vacuum, but every time I hear it suck air back in as soon as I stop squeezing. Any other tricks?

[Kiwi7475]

@Kiwi7475, yes it's possible, and I found another example on the board here with the same error. First time in 32 sheets!

One question re: the SP 445 -- it is still leaking all over when I try to invert. I am wetting the O-ring, using 450 ml solution, squeezing / raising the water level to get a vacuum, but every time I hear it suck air back in as soon as I stop squeezing. Any other tricks?

Did it started doing that now or was it always leaking? I don’t wet the ring and for me the squeeze is enough... most times don’t even need to squeeze and it never leaks. Something looks defective or worn out such that it can’t keep internal “vacuum”. Have you tried reaching out to the Stearman guys? They’re usually very helpful and if you explain it to them or send them a video showing the leak maybe they can troubleshoot it with you or send you a new lid or something....