Odd stains/streaks on underexposed film

NewDarkroom

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Hello! I have had an issue with streaks appearing on underexposed films recently and was wondering if anyone had any ideas as to what could be happening.

My process is this:
Develop with Fuji Hunt Chems in Patterson tanks, bleach, wash with tap water, fix, wash with tap water, then final rinse with flexicolor final rinse and a bit of photo-flo.

It seems to happen mostly near the end of the roll, and is especially bad in thin areas of the negative.

Any ideas?
 

koraks

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The first thing that comes to mind is insufficient agitation. Keep in mind that the C41 process was engineered with constant agitation in mind; you'll have to try to approach that as closely as you can with the Paterson tank.
 
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OP

NewDarkroom

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koraks said:
The first thing that comes to mind is insufficient agitation. Keep in mind that the C41 process was engineered with constant agitation in mind; you'll have to try to approach that as closely as you can with the Paterson tank.
Click to expand...

That is a real possibility, it doesn't happen all the time. But especially on thin negatives or in thin spots of a negative.
I agitate for 10 seconds every thirty seconds with inversions.
 

koraks

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Do you start with 30 seconds continuous agitation?
Don't invert too cautiously; keep in mind that the purpose is to replace developer at the surface of the film with fresh material, so it is OK if it's a little fierce (without splashing liquids all over the place).
 
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NewDarkroom

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Yea, I do the first 30 seconds with the twizzle stick so that I can do it right away before fumbling with the lid.
I also thought that this might be caused by over agitation? Like the chemicals surging through the reels might streak it.
Or potentially a weak bleach not stopping the developer quickly enough?
 

koraks

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The twizzle stick may not be effective unless you're rather violent with it; if you're rotating it carefully, you're probably not doing it right.
NewDarkroom said:
I also thought that this might be caused by over agitation?
Click to expand...

No, I don't think so.

NewDarkroom said:
Or potentially a weak bleach not stopping the developer quickly enough?
Click to expand...

Perhaps, but again, I don't think so. If you wonder about this, try a stop bath (which I'd recommend anyway) of 0.5% to 2% acetic acid.
 
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