Please tell me what I'm doing wrong here

[nephilim]

Hi!

After approx a year of developing film I've encountered a nasty issue for the first time. Tonight I developed three rolls of 120 film (2x Trix 400 and after that TMax 100) in Rodinal. The workflow was the same for all rolls:

- film on dry plastic spool of A&P tank
- developing in Rodinal 1:50, 60sec of const. agitation, two-three hard "touch downs" to get rid of bubbles, then one inversion each 45sec
- stop bath
- fixer
- rinsing
- wetting agent
- drying

When I looked at the drying film, I noticed some nasty spots:

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DSC_7500 von Torsten Wolf auf Flickr

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DSC_7498 von Torsten Wolf auf Flickr

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DSC_7497 von Torsten Wolf auf Flickr

The spots are along one side of the film only. I've used a fresh bottle of fixer and changed to new stop concentrate for the last roll. The only thing I noticed was, that there seem to be quite a few crystals in the Rodinal bottle.

What do you think went wrong here?

Cheers,
Torsten

 

[shadowkon]

It doesn't look like underfixing.
Looks more like stain on the film base itself.

Did you try dipping the spots in fixer? just in case?

 

[nephilim]

I just soaked a q-tip with fixer and tried to rub off one of those spots... no success.

 

[Chris101]

Looks like the film has been splashed with chemicals prior to processing or maybe air bubbles during . Perhaps grains of undissolved developer? If it persists try giving the film a pre-soak and filtering your chemicals before use. How hard is your water? Very hard water will inhibit dissolution, if you have 600 mg/L or more (as CaCO3) then try heating the developer and fixer to about 50 C or so prior to use, but be sure to cool them before using!

edit: Are they all on the edge? If so, then you are not using enough solution in the tank - fill it all the way up!

 

[nephilim]

Thanks Chris! I'm still scratching my head:

Looks like the film has been splashed with chemicals prior to processing or maybe air bubbles during .

Two of the rolls were mine, the third came from a friend. All of them were rolled onto a dry spool and put in the tank, which was then filled with the Rodinal dilution. For rolls #2 and #3, the tank was still wet inside, but there are also spots on the first film. I also tried to prevent bubbles by giving the tank a few stronger thuds, especially after the initial agitation, and softer ones later.

Perhaps grains of undissolved developer? If it persists try giving the film a pre-soak and filtering your chemicals before use.

While pouring the pure Rodinal into the measuring cylinder, I heard that the number of crystals has increased quite a bit. But then I'd guess that they don't come out of the bottle very easily as long as you pour slowly. Ok, instead of guessing, I'll pour some Rodinal through a filter and see if there is any solid stuff in it.

How hard is your water? Very hard water will inhibit dissolution, if you have 600 mg/L or more (as CaCO3) then try heating the developer and fixer to about 50 C or so prior to use, but be sure to cool them before using!

I don't know the water parameters here in Berlin, but at least I've done all developments in the same place. If the water company hasn't changed something I'd expect similar results as from previous rolls.

edit: Are they all on the edge? If so, then you are not using enough solution in the tank - fill it all the way up!

According to the tank, at least 590ccm are needed for 120 film. For easier calculations, I'm starting with 650ccm water and add the chemistry. Rodinal at 1:50 results in 663ccm dilution, which fully cover the reel (just checked)

I wish I could find out if the spots are on the edge at the bottom or top of the tank!! This would probably help a lot. I somewhat suspect undissolved developer...

 

[Chris101]

...

I wish I could find out if the spots are on the edge at the bottom or top of the tank!! This would probably help a lot. I somewhat suspect undissolved developer...

Yes, this would be a big clue! On the top would indicate insufficient coverage (fixer? stop? probably not developer from your description.) The bottom would almost certainly point to undissolved solids. When I have seen problems from solid contaminants, it has not been roundish blobs though. Usually an irregularly shaped mark with a halo of affected area around the mark. Completely unlike your blobs, which look similar to bubbles to me. Any chance of oil or solvents in the water?

You can check the hardness of your water (ours changes a lot here in Arizona, but then we are famous for hard water) by putting a drop of detergent in a bowl of water, wisking it up until foam appears and then timing how long it takes for the foam to disappear. The faster it does, the harder the water. At about 600ppm (mg/L) the foam disappears right away.

The issue with hard water is that chemistry will dissolve very slowly, hence my recommendation t gently heat the solutions prior to mixing.

Another possibility is any contact with the film after processing. Do you use a squeegee? Or anything that contacts the film when it is wet? And if so, is there any chance of contamination there?

 

[nephilim]

Yes, this would be a big clue! On the top would indicate insufficient coverage (fixer? stop? probably not developer from your description.)

Forgot to say, that for stop bath and fixer the amount of dilution is even higher (680ccm & 720ccm).

The bottom would almost certainly point to undissolved solids. When I have seen problems from solid contaminants, it has not been roundish blobs though. Usually an irregularly shaped mark with a halo of affected area around the mark. Completely unlike your blobs, which look similar to bubbles to me.

:frown: I hoped that was the reason (easy to solve) but apparently it's unlikely, too.

Any chance of oil or solvents in the water?

Hopefully not! It's water from the tap (which I'm drinking btw), so I hope it's clean. In addition, everything has been rinsed multiple time during that evening, so I'd assume that any residue in the measuring jugs would have been gone by then.

You can check the hardness of your water (ours changes a lot here in Arizona, but then we are famous for hard water) by putting a drop of detergent in a bowl of water, wisking it up until foam appears and then timing how long it takes for the foam to disappear. The faster it does, the harder the water. At about 600ppm (mg/L) the foam disappears right away.

The issue with hard water is that chemistry will dissolve very slowly, hence my recommendation t gently heat the solutions prior to mixing.

We have relatively hard water here, but it's not brutal yet Heating would be my last try, as it would slow the process down quite a bit.

Another possibility is any contact with the film after processing. Do you use a squeegee? Or anything that contacts the film when it is wet? And if so, is there any chance of contamination there?

I saw the spots as soon as I opened the reel after washing and resting in the wetting agent for a few minutes. I'm thinking about shooting a test roll and repeating the process more carefully (Rodinal crystals, longer mixing time, check before adding wetting agent) and see what comes out of the tank.