View Full Version : Help Identifying Problem in C-41 Process Run

24-Nov-2016, 14:38
Hi all,
I experienced some strangeness in a C-41 development run, and hope that someone might be able to help me nail down the error in my process.

I shot four sheets of Portra 400 in my camera, using both sides of two separate film holders.

I loaded the sheets into a Jobo 2520 drum on 2509 reels, and processed the run in a leveled Jobo CPE-2 processor using an Arista C-41 liquid kit. The chemistry was fresh, and processed at the appropriate temperature.

Of the four sheets in the drum, two exhibited the strange patterns shown below. The other two processed perfectly.

The two that processed well were on the same side of the 2509 reel, and the two that had problems were on the other side. The two that processed perfectly were from a single film holder, and the two that had problems were from a separate film holder.

Because the two problematic sheets were both from a single holder, and both processed on the same side of the Jobo drum, I think that the problem is either with the holder or drum.

The problems on the images don't look that the "normal" light leaks I'm used to with bad film holders.

I would think that the drum's rotation would negate any "good side" or "bad side" of the tank/reels.

It's possible that I somehow misloaded the two "bad" sheets into the drum.

Thank in advance for any help troubleshooting this issue.

Good sheets:

http://i.imgur.com/8djy0rgm.jpg (http://imgur.com/8djy0rg)

Bad sheets:

http://i.imgur.com/8t7kzfVm.jpg (http://imgur.com/8t7kzfV)

25-Nov-2016, 13:18
Not experienced with C-41 chem yet, but wanted to share I had the same experience (2 sheets bad, 2 sheets good) in B&W batch recently. The bad sheets looked just like yours.

Found out a small amount of light was sneaking in through an outlet in my darkroom! Just so happened that I had my back turned that way when I opened the good ones.

Is it possibly a bad darkslide or other light leak in your process?

25-Nov-2016, 16:02
Unlikely, but possible. Hmm.

Jim Michael
25-Nov-2016, 16:10
Might the bellows extension for your closeup be permitting light leaks you don't have with other images?

25-Nov-2016, 16:50
Jim, no. Zero issues on some black and white shots of same scene. The bellows are sound. Great idea though.

The problems are "diffuse" not like point like leaks.

This film had sat, loaded, in a brand new Toyo holder for like six months. I'm wondering if there was some outgassing or something.

25-Nov-2016, 16:55
Holy smokes, this is it: Toyo darkslide problems.


25-Nov-2016, 17:26
I just bought 8 "new" Toyo holders and found that thread too. Thought for sure that was the cause. However, I shot again on the problem holders and they were fine. So I think the problem slides were fixed in my batch, but maybe not for you?

Puzzled, I began hyper-attentively triple checking everything in my process when I stumbled upon the outlet in my darkroom. Not sure why it was never a problem before. No issues since all that.

Hopefully you've found the source. A couple test shots will probably tell you. Cheers!