c41 marks

EcZc

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• Jun 8, 2011

• #1

Hi

Could anyone tell me what they think is the most likely cause of the marks in the sky on the attached negative? The negatives were developed with a Jobo, fresh chemicals, pre-wash, washes between bleach/fix and fix/stabalizer, correct temperature and great care not to cross contaminate chemicals. Could it be anything to do with having more than one film on a reel at a time? It only seems to affect 120 and 5x4 - 35mm come out great.

Thoughts appreciated!

 

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epatsellis

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• Jun 8, 2011

• #2

While I realize that many advocate a prewash and rinse, I have followed the Z131 reccomendations for rotary processing and get nothing but perfect negatives every time.

 

timparkin

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• Jun 8, 2011

• #3

How long pre-wash are you doing? I've had this happen a lot until I started doing a two minute pre-wash (I actually do longer than this out of paranoia) ..

Could be the warm up too - 35mm probably warms up very quickly.. Just a thought... (I think not but worth mentioning)

 

Sirius Glass

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• Jun 8, 2011

• #4

I used a five minute prewash per the Jobo and Unicolor kit.

Steve

 

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EcZc

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• Jun 8, 2011

• #5

Good point on pre-wash length / film size. I'm using a pre-wash of 3 to 5 mins. I'm not checking the exact temp of the pre-wash water though, I just mixing it reasonably warm - not hot.

I always rinse reels under clean water, I read recently they should be scrubbed to get rid of stabalizer. Any chance this could be the cause?

 

Sirius Glass

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• Jun 8, 2011

• #6

Part of the reason to prewash is to get the film to the proper temperature.

 

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EcZc

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• Jun 8, 2011

• #7

So what temperature should the pre-wash water be? I had consistent good results for over a year and never checked pre-wash temperature, just gave it 3 mins with 8x10, 5x4 and 120. I thought pre-wash got to roughly correct temp but more importantly allowed even absorbsion of the dev.

 

timparkin

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• Jun 8, 2011

• #8

Should be the same temp as the processing...

 

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EcZc

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• Jun 8, 2011

• #9

Well yes, obviously I guess, but it still doesnt add up for me as it has never caused issues before.

 

Sirius Glass

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• Jun 8, 2011

• #10

EcZc said:

Well yes, obviously I guess, but it still doesn't add up for me as it has never caused issues before.

Click to expand...

Large differences in temperature can cause reticulation. You may have been lucky.

 

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EcZc

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• Jun 8, 2011

• #11

But lucky in over 250 sheets of 5x4 and 100 rolls of 120?