Strange coloured film base

[Filmandfile]

Hi there can anyone tell me why I’m getting such different colour bases from Bellini and Adox c41 chemicals (Bellini left, Adox right) both hand developed in Paterson tank with all conditions exactly the same and chemicals around same age. Needless to say the Bellini scan a lot better.

 

[koraks]

It looks like the strip on the right suffers from excess cyan dye formation/fog.
Can you explain your development process in detail?
Was the ADOX chemistry fresh, or had it been used before?

 

[Filmandfile]

It looks like the strip on the right suffers from excess cyan dye formation/fog.
Can you explain your development process in detail?
Was the ADOX chemistry fresh, or had it been used before?

Hey thanks for the reply, the chemistry was new and I’ve stopped using it because of funny results over the last couple of kits.

With the adox:
Prewash film in de ionised water for 5 mins at same temp as dev

Dev: 3:15, invert for first 45 seconds and invert once every 15

Wash under running water 1:30

Blix 5 mins invert first 45 and once every 15

Wash under running water 6:00

Stab

Bellini:

Pre warm film in tank in water bath (dry tank)

Dev 3:15 invert first 45 then invert once every 15

Bleach 2 mins continuous inversion

Wash 1:30 under running water

Fix 3 mins continuous inversion

Wash 6 mins under running water

Stab

 

[koraks]

Dev: 3:15, invert for first 45 seconds and invert once every 15

Wash under running water 1:30

I would start by introducing a stop bath after development. It's OK to wash after the stop, but it's not a good idea to have a long water wash right after development. What will happen is that development continues as a result of developer remaining active esp. in the lower part of the emulsion (where the cyan dye is formed). If you introduce a stop bath, this prolonged developer action should stop immediately.

I notice that with the Bellini chemistry you go from development straight to bleach; the bleach is slightly acidic and strongly buffered, so it effectively also acts as a stop bath (it's deliberately engineered this way, too). So this may very well account for the difference you're seeing.

I have no experience myself with blixes for C41 film, and opinions are mixed. Some find it works just fine for them, others contend that they never get quite as good results with blix as with separate bleach and fix. However, I've never seen evidence of such major differences, so I don't think this in itself explains the issue you're seeing.

 

[Filmandfile]

I would start by introducing a stop bath after development. It's OK to wash after the stop, but it's not a good idea to have a long water wash right after development. What will happen is that development continues as a result of developer remaining active esp. in the lower part of the emulsion (where the cyan dye is formed). If you introduce a stop bath, this prolonged developer action should stop immediately.

I notice that with the Bellini chemistry you go from development straight to bleach; the bleach is slightly acidic and strongly buffered, so it effectively also acts as a stop bath (it's deliberately engineered this way, too). So this may very well account for the difference you're seeing.

I have no experience myself with blixes for C41 film, and opinions are mixed. Some find it works just fine for them, others contend that they never get quite as good results with blix as with separate bleach and fix. However, I've never seen evidence of such major differences, so I don't think this in itself explains the issue you're seeing.

Ah right I see, I was going by the Adox instructions, would you recommend an acetic acid stop bath?

 

[koraks]

Yes, that will generally work just fine. E.g. 1% acetic acid. The concentration isn't critical. Use it once, then discard.

 

[Filmandfile]

Yes, that will generally work just fine. E.g. 1% acetic acid. The concentration isn't critical. Use it once, then discard.

Thankyou, how long for an continuous inversion?

 

[koraks]

30 seconds would be OK. Technically, 10 should already be OK, so 30 seconds gives you a safety margin. There's not much benefit in a longer time, although up to a minute or so won't do harm either.

 

[Filmandfile]

Okay, thankyou for your help!

 

[koraks]

Sure thing, hope it helps!

 

[Lachlan Young]

Prewash film in de ionised water for 5 mins at same temp as dev

This is a strong contender for the cause of the problems.

Unless you are measuring temp in and temp out and they are within tolerance, you are potentially causing crossover issues from uneven temperature, and/ or are potentially diluting the developer from carryover.

 

[koraks]

@Lachlan Young through which mechanism would this explain the excess cyan dye formation in the unexposed areas that we're seeing?

 

[brbo]

I would be REALLY surprised if either prewash or absence of stop after development would have such a huge effect.

 

[koraks]

I would be REALLY surprised if either prewash or absence of stop after development would have such a huge effect.

Prewash, yes. Concerning the stop: if he would go from dev to blix, then I'd expect everything to be OK but with ramifications for the lifetime of the blix. But a 90 second water wash after development with carried-over developer is asking for problems.