Strange green streaks on C41 8x10 negatives

[Dhuiting]

Hi all, I have some strange green streaks on a negative that look to be something to do with something running down the negative during development. (I use a Jobo CPA-2., and the motor only goes one way, but that has not negatively affected anything and even after this negative I continue to make great-looking negs in the machine.) I did 4 negatives in this batch and the other 3 turned out just fine and with no problems at all.

I've had streaks before, but they were pink, and after posting on the forum and tons of other folks saying it was just "light leaks," I had a hunch that wasn't it. I had a hunch that the fixer hadn't fully done its job removing the silver halide, and sure enough I threw the negs back in the blix and the pink streaks went right away. Problem solved, I thought.

Now, I have streaks that are green. I threw this neg back in the blix today (which is days later, and after stabilizing it initially when I developed it last week) and the streaks are still there. So I'm wondering if anyone has any idea what the deal is. The pink streaks I had before were excess silver halide, but these green streaks I have no idea. The chemicals I used were the Arista c41 kit, with an added stop bath in between developer and blix (on the advice of forum member PE to make it easier for the blix to do its job).

Here is a detail of the problem:

Any ideas why?

[Steven Ruttenberg]

Your positive the film holder was completely seated? I had multi colored and angled streakks on some negatives and after racking my brain, i realized I had put the gg holder in 180 degrees out. The idiot proof Toyo (I am being facetious here) let me put the film holder in with no indication it was not seated properly. So I ended up wih streaked negatives. Anyhow just a thought to make sure it is fully seated.

Does it do it on only one film type or different film types?

[stefan dinu]

try extending the stop bath. I use two plain water baths first 45 sec and second over 2 min. It seems to be a problem of contamination between colour dev and blix if it is based on potassium bichromate. I had the same problem before and fixed after extending the wash between baths.

[Dhuiting]

try extending the stop bath. I use two plain water baths first 45 sec and second over 2 min. It seems to be a problem of contamination between colour dev and blix if it is based on potassium bichromate. I had the same problem before and fixed after extending the wash between baths.

Thanks Stefan, a lot of my research online also points to the possibility of contamination from carryover of the developer into the blix stage, so I will try to increase my stop baths.

I also am wondering if I decide to order the Fuji Hunt c41 kits, which have bleach and fixture as separate steps, if that will help. I'm told that only home kits utilize the blix concept, and "proper labs" usually have a separate bleach and separate fixer step. But I'm not entirely sure why. I know that the bleach and fixer sort of work against each other, because the bleach is trying to convert the silver into silver halide while the fixer is trying to remove the silver halide, but I don't yet know the full scope of why a separate bleach and fixer is so much more "professional" than using blix. Any idea why? Are there bleach and fixer very different in terms of alkalinity or acidity and that's why they work against each other?

...As for the light leak idea, it's not that. I've seen a lot of light leaks in my day and none would be that specific of a shape on the negative. Thanks for the suggestion though!

[stefan dinu]

It is true, I never had this problem with Fuji Hunt chemicals and having separate baths for bleach and fix also increase the life of the chemicals. Also, if you need true push and pull techniques on C41 you need separate baths. That being said I still work mostly with blix kit but the extended wash resolved the problem. Also, take your time pouring out everything from the tank between baths. Drain it good between washes.

[Dhuiting]

Sounds good, thanks Stefan! I guess I've always tried to get the developer poured out as fast as possible so as to keep the dev time as close to the 3.5 mins (at 104 f) as possible, because if I drain the 3005 drum really good it seems to add an extra 30 seconds to the dev time (which I'm afraid will be tantamount to pushing the neg). But I suppose I can start dumping it out sooner? Up until now, I have been starting to drain it around 20 seconds before the cycle is done.

[domaz]

try extending the stop bath. I use two plain water baths first 45 sec and second over 2 min. It seems to be a problem of contamination between colour dev and blix if it is based on potassium bichromate. I had the same problem before and fixed after extending the wash between baths.

Hmm I would hope modern C-41 blix kits wouldn't contain Dichromates, a cursory check of some common kits on Freestyle doesn't indicate any do.

[Dhuiting]

Thanks all.

I ordered the Fuji Hunt kit.

I have another question though with regard to using the fuji hunt kit. I usually (when using blix-based kits) do half the Blix time in the 3005 drum, and then take the negs out and in the light do the rest of the time in a tray with the blix (and of course, a water jacket in a larger tray underneath to keep it at a similar temp). I started doing this when I would get the opposite color blotches (navy blue on the negs which would look pink on the scanned image) from places on the backside of the neg that touched the drum and the fixer couldn't clear. I then took one of these blotchy negs and re-blix it and it cleared the blotches instantly. So I started doing the half drum/half tray blix method and never had that problem again.

But I could expose the negs to light because they had been fixed for a couple minutes first, right?

Because if i want to use the half drum/half tray method with the bleach, and then with the fix (or maybe just go all tray with blix at that point since the negs are out of the drum at that point), I'll have to make sure the negs are light safe first. Does a couple minutes in the bleach in the drum make them light safe?

Or is the bleach really only for the emulsion side of the neg and I can just do the ENTIRE bleach step in the drum and then keep doing my half drum/half tray method with the fix after that?