c41 uneven development?

[Zaitz]

My own attempts at developing c41 weren't going very well so I decided to send the last batch out again. Am I expecting too much or is there some other issue here? Looks like some form of uneven development to me. I applied a very heavy curves adjustment layer to make the marks more visible. But I do feel it can be subtly spotted in blue skies. The marks also show up more the more I edit the photo. I can even see the marks on the straight conversion with no editing.

http://imageshack.us/a/img163/210/09jn.jpg

http://imageshack.us/a/img822/4355/8fv9.jpg
On Portra 400 scanned in with an Epson 4990 and converted from raw positive with colorperfect.

I am guessing I am expecting too much. But on another photo with just some smooth blue sky I could see a hint of the same marks and I felt I needed to cover it up with a gradient overlay masked in. I am not editing to the point of the second image but, to me, once the marks are visible, on any level, it's no good.

[Daniel Stone]

looks like there is insufficient agitation. probably during the bleach step.

agitation w/ c-41 is IMPERATIVE, seeing that the development time is very short compared to most b/w or the standard E-6 process.

I'd look at using a different lab, a place that gets LOTS of use. Labs don't stay in business if they continually screw up peoples orders.
Edgar Praus ( http://www.4photolab.com/ ) does great C-41, and he stays very busy with mail-order clientele.

best of luck

-Dan

[Zaitz]

Yeah that is probably where I'll go next. Thanks for the info.

[Ari]

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

I had very bad unevenness in my initial C-41 attempts, until it was suggested to me to use two pre-soak water baths, instead of one.

The difference was immediately obvious and the unevenness disappeared.

[Daniel Stone]

DIY c-41 is extremely simple, and the cost savings can really add up if you shoot a good bit. You also get free pushes + pulls :)

Like Ari, I use (2) separate pre-soak baths BEFORE development.

[Zaitz]

I thought it was simple but my last batch looked quite poor as you can see from my previous thread. Though, these were lab processed and aren't 100% perfect either. Really unfortunate to shoot 4x5 (expensive c41 at that) and not see the quality you desire, for whatever reason. Will probably just send to Praus with my next batch.

[frotog]

Praus is good but LTI lightside is better. They have a proprietary "special process" c-41 line that really works. I used to send my film to Praus labs but now LTI gets all my business. I don't mind paying a bit extra if it means no more mottled skies.

[Corran]

Zaitz - I got mottled skies from my preferred lab too, which was the last straw that got me really interested in doing it myself. I agitate with a dip 'n' dunk type processing every 15 seconds with C-41. I haven't had any problems.

Your original thread with the totally destroyed negatives is a different problem and I'm not sure what happened there - looks like chemical contamination or something.

I use a Calumet water heater/pump to maintain a water bath at 101F, and 3 metal tanks with 2L of chemistry each for development.

[Zaitz]

I was using constant agitation because that is what Kodak's procedure calls for so that shouldn't be an issue for me. I usually don't have many photos at once so the BTZS tubes small volume seemed to work well but perhaps it's just not enough developer. I don't like saving up film over time to do a run so doing it myself probably isn't worth it if BTZS tubes don't work well. Will probably just send to Praus or LTI.

[Corran]

I did it in BTZS tubes for a little while but I got frustrated with the amount of time each individual sheet took.

Honestly using a 6-sheet holder alleviates my fear of shooting color film and it taking forever to develop or cost a ton. I'll shoot 6 sheets of E6 in an afternoon no problem now, rather than hording it and shooting sparingly.

[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?

[Dave Langendonk]

Dave, last night I did my third run of 8x10 (Efke 50) in a Jobo drum...

I'm referring to C-41 processing, not B&W. I have no problems with B&W. They come out perfect. Development time for C-41 at 100 degrees is only 3 minutes 15 seconds. Very short for rotary processing and for 8x10 it's very prone to uneven development. Thanks for the comment though.

[koh303]

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.

Looking at the scanner cannot hurt, especially since it will take all of 20 seconds to rule it out. Until that is ruled out all the MANY pots on this thread are theoretical ASSumptions.

[frotog]

Wrong. I know what bad rotary artifacts look like just as I know what scanner banning looks like. This is experiential, not theoretical. The OP's problem is uneven development. Stick to slinging processors.

[Daniel Stone]

Wrong. I know what bad rotary artifacts look like just as I know what scanner banning looks like. This is experiential, not theoretical. The OP's problem is uneven development. Stick to slinging processors.

While I agree with you on the uneven development issue. However, depending on the scanner used and its age(potentially), that could play a part in the equation as well.

Case in point:
A local photo center where I do the majority of my darkroom-related work at the moment has 2 Imacon flextight scanners, an 848 and a 646. Unfortunately they do not get serviced as frequently as I would like, so they occasionally have banding issues. I've mentioned this to them before, but it seems to fall on deaf ears most of the time. The line of "we have experienced budget cuts, so we'll attend to it when we have the funds" can only go on for so long. But they have a few Epson flatbeds which occasionally band as well.
sorry to ramble.
But there CAN be issues(at least in my experience) with banding, and it not looking like a hard line. Occasionally the banding can look like a light leak, aka it "fades" away from the point of origin in terms of density. Similar to what the OP has shown in his shots(towards the left edge on the 1st shot in particular).

-Dan

[LF_rookie_to_be]

My Scanmate drum scanner from 1995 also has banding issues at times, and they're 100% related to memory and SCSI. A simple procedure of reinstalling SCSI card drivers, restarting and doing several full-drum previews in ColorQuartet (OS X 10.4 system) solves the problem. The lines vary in appearance - hard, one-pixel wide, soft, entire/partial drum circumference, "fading", etc.
Dave, I'm yet to develop 8x10" colour negatives, but I wouldn't do it with less than 750ml for 4 sheets in my lid/3004 setup. This week I'll be developing ten 4x5" C41 sheets with 400ml in a 3010 drum. It's my standard volume for 4x5" C41 (and E6) and so far, no streaking issues. I agitate and roll the drum as much as possible and very fast.

[koh303]

As a matter of experience, imacon machines (and many epson units) often get dust particles to rest on the light bulbs, resulting in lines across the direction of the scan. As the negative is curved, or the scanning head moves the lines vary in width, sharpness and density. This is just one of many other causes of "banding" or "unevenness" in scanning negatives. If the issue on these negatives is not visible to the naked eye there is no way to tell where the issue is. Since checking the scanner takes only a few seconds, why would anyone be against ruling it out? The worst that can happen is to find that it is after all a good scanner, and bad negative development...?

[Dave Langendonk]

...Dave, I'm yet to develop 8x10" colour negatives, but I wouldn't do it with less than 750ml for 4 sheets in my lid/3004 setup. This week I'll be developing ten 4x5" C41 sheets with 400ml in a 3010 drum. It's my standard volume for 4x5" C41 (and E6) and so far, no streaking issues. I agitate and roll the drum as much as possible and very fast.

Sorry for the VERY late reply. I haven't been on the forum lately. I use 1000ml when I do 8x10 in the 3005. I don't believe that is the problem. As I mentioned, I only see this issue with 8x10 C-41. 8x10 B&W are fine since the development time is much longer. 4x5 C-41 also come out fine in a 3010 drum. I have more testing to do but at $12/sheet, testing gets expensive quickly. I process on a Jobo 2300 automated processor and will do some rotation speed changes to see what that does. I use 50 rpm currently as recommended by Jobo for the Expert drums.

BTW, 400ml seems a bit light for 10 4x5's. It may be enough volume to cover the sheets but wonder if it's enough developer to develop them fully. Kodak recommends 3 8x10 equivalents per liter or 10 per gallon for Flexicolor. YMMV.

I wonder if the OP solved the unevenness problem? Zaitz?