What is causing these streaks during development?

Sjixxxy · Apr 5, 2020

This was processed in a Jobo CPE-2 in a 2500 tank using Kodak Flexicolor chemistry. This frame was midroll on the roll of film. A few other frames also have these streaks, but not all of them. Also have noticed it, albeit more faintly on some 120 film I've processed as well.

The tank was tempered in the water bath without a presoak. 3:15 dev. 30-second rinse. 6:30 Bleach. 3-minute wash. 6:30 fixer: 5-minute wash. 1 min final rinse.

Two rolls of film were in the tank, this one would have been occupying the top area closest to the lid. Since it runs across the frame it seems like it is something that would be happening during chemical changes then the tank is set upright.

Any advice on how to deal with this going forward?

alanieon · Apr 13, 2020

i hv similar issue, which solve the problem by introducing a prewet and a stopbath step before and after the dev step.

Sirius Glass · Apr 13, 2020

alanieon said:
i hv similar issue, which solve the problem by introducing a prewet and a stopbath step before and after the dev step.

Those tow are the solution to these problems almost always.

KenS · Apr 13, 2020

Sjixxxy said:
This was processed in a Jobo CPE-2 in a 2500 tank using Kodak Flexicolor chemistry. This frame was midroll on the roll of film. A few other frames also have these streaks, but not all of them. Also have noticed it, albeit more faintly on some 120 film I've processed as well.

The tank was tempered in the water bath without a presoak. 3:15 dev. 30-second rinse. 6:30 Bleach. 3-minute wash. 6:30 fixer: 5-minute wash. 1 min final rinse.

Two rolls of film were in the tank, this one would have been occupying the top area closest to the lid. Since it runs across the frame it seems like it is something that would be happening during chemical changes then the tank is set upright.

Any advice on how to deal with this going forward?

If my ageing memory serves me.. I've seen similar problems others have had.
I believe it is caused by having a "kink' in the film while loading it onto (into?) the reel.

Ken

koraks · Apr 14, 2020

This looks like a problem associated with fluid dynamics in the tank.
* When filling the tank, make sure to be as quick as possible in filling it and mounting the tank to the rotary processor (if used) or start agitation immediately upon filling the tank.
* Use an acetic acid stop bath (0.5-2% concentration) after development and before the 30 second rinse
* Use absolutely no less than the minimum amount of chemistry indicated on the tank.

alanieon said:
i hv similar issue, which solve the problem by introducing a prewet and a stopbath step before and after the dev step.

A prewet is never required in my experience, regardless of film format, development tank used, etc. YMMV.

foc · Apr 14, 2020

I have no experience od processing C41 as described by the OP but I have done for many years commercially using automated processing machines.

koraks said:
A prewet is never required in my experience, regardless of film format, development tank used, etc. YMMV.

I have never know the need for a prewash with C41 and it is my understanding that it is designed not to use it.
A stopbath after the dev can be used when processing manually but it's not used commercially (as the timing and chemical circulation is carefully controlled).

Anon Ymous · Apr 14, 2020

A water rinse between C41 developer and bleach is a bad idea and probably the cause of this problem. Use an acetic acid stop bath as koraks said if you don't want to go straight from developer to bleach. Bleach by the way is plenty acidic and will stop development just as well. There's also no need to rinse between stop bath and bleach if you use one. C41 bleach will likely contain quite a lot of acetic acid anyway. The only rinses that you definitely have to do are after bleach and fixer.

Adrian Bacon · Apr 21, 2020

Sjixxxy said:
This was processed in a Jobo CPE-2 in a 2500 tank using Kodak Flexicolor chemistry. This frame was midroll on the roll of film. A few other frames also have these streaks, but not all of them. Also have noticed it, albeit more faintly on some 120 film I've processed as well.

The tank was tempered in the water bath without a presoak. 3:15 dev. 30-second rinse. 6:30 Bleach. 3-minute wash. 6:30 fixer: 5-minute wash. 1 min final rinse.

Two rolls of film were in the tank, this one would have been occupying the top area closest to the lid. Since it runs across the frame it seems like it is something that would be happening during chemical changes then the tank is set upright.

Any advice on how to deal with this going forward?

how much chemistry are you using? Are you doing an acid stop bath or plain water between the developer and bleach? It should be an acid stop bath as you want to stop development as quickly as possible after the developer leaves the tank.

Lachlan Young · Apr 21, 2020

Get rid of the rinse between developer and bleach. It's that simple.

What is causing these streaks during development?

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What is causing these streaks during development?

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