c41 uneven development?

[Dave Langendonk]

If you plan on trying it at home again, use two water pre-soaks...

Can you elaborate? how long for each? How are you processing? What size film? I'm having a tough time with 8x10 in Jobo 3005 expert tanks. The developing time at 100 degrees is short and very prone to uneven developing. I don't have this problem with 4x5, only 8x10. I believe it takes too long for the solution to get to the far end of each tube in the 3005. As a result there may be a rotation or two before the negative gets fully immersed in developer. Since development is so rapid at 100 degrees, you can see these rotation marks especially in sky areas. I'm doing one water pre soak now. Not much different than with no pre soak.

[Daniel Stone]

Dave,
I use (2) 1min pre-soaks before the developer.
Used to do it on 8x10(with a 3005), now do it on 5x7. Haven't had a problem yet.

Same for rollfilm and the few occasional 4x5 sheets.

B/W film gets (2) 1min soaks as well.
Dan

[LF_rookie_to_be]

As others stated, constant agitation during entire developing is the key. I do 4x5s in a 3010 with a home-modified (cupped) lid and drift-through temperature technique and every sheet turned out perfect so far. Do presoak.

[koh303]

This seems more like scanner banding then anything else.
Can you see the issue with the naked eye?
If you move the negative on the scanner bed from vertical to horizontal, do the marks remain in the same place?

[Ari]

Can you elaborate? how long for each? How are you processing? What size film? I'm having a tough time with 8x10 in Jobo 3005 expert tanks. The developing time at 100 degrees is short and very prone to uneven developing. I don't have this problem with 4x5, only 8x10. I believe it takes too long for the solution to get to the far end of each tube in the 3005. As a result there may be a rotation or two before the negative gets fully immersed in developer. Since development is so rapid at 100 degrees, you can see these rotation marks especially in sky areas. I'm doing one water pre soak now. Not much different than with no pre soak.

Dave, the pre-soak procedure is exactly as Dan describes.
I originally got the advice from him

[Dave Langendonk]

Thanks Dan & Ari. I'll give it a try.

Sorry Zaitz for the slight thread jack. You're kind of between a rock and a hard place. If you don't do enough C-41 it's probably not worth doing at home. But if you can't find a pro lab that meets your requirements you're kind of stuck. Despite my problems with 8x10 negs, my 4x5's in a 3010 expert drum come out perfect. Just shoot more and then do them at home. We'll help you get it right. I do wonder about the lines you see however and agree with the suggestion for scanning in another direction and see if the lines are still in the same place.

Dave,
I use (2) 1min pre-soaks before the developer.
Used to do it on 8x10(with a 3005), now do it on 5x7. Haven't had a problem yet.

Same for rollfilm and the few occasional 4x5 sheets.

B/W film gets (2) 1min soaks as well.
Dan

[Zaitz]

It's no problem! I enjoy the discussions here. Thanks for all the info. I didn't think of the scanner, will have to check that. Though, these marks are pretty much exactly the same as some I got on 8x10 Velvia slides from the same lab.

[Daniel Stone]

Find yourself a new lab altogether

[frotog]

Don't bother looking at the scanner. The artifacts are due to poor agitation in development and/or aerial oxidation between baths. If you're spending the coin to shoot 810, you owe it to yourself to check out LTI/lightside.

[LF_rookie_to_be]

I'm having a tough time with 8x10 in Jobo 3005 expert tanks. The developing time at 100 degrees is short and very prone to uneven developing. I don't have this problem with 4x5, only 8x10. I believe it takes too long for the solution to get to the far end of each tube in the 3005. As a result there may be a rotation or two before the negative gets fully immersed in developer. Since development is so rapid at 100 degrees, you can see these rotation marks especially in sky areas. I'm doing one water pre soak now. Not much different than with no pre soak.

Dave, last night I did my third run of 8x10 (Efke 50) in a Jobo drum. It's a 3004 drum, so it has inner compartments of a slightly larger diameter and requires more solution than 3005. Used 700ml of 1+25 R09 One Shot for three sheets, preceded by two short presoaks and stopped in a very weak dilution of common white vinegar. Did it all hand-rolled, but the lid I have is a home-modified with a 750-ml cup on the underneath, so the liquid reaches film only when the drum is turned to the horizontal position and rotated - exactly as in a Jobo processor. Absolutely no streaks of any kind. Could it be the developer you're using?