Re-bleach/fix colour negatives?

FujiLove · Feb 14, 2018

Last night I printed a few contact sheets from Ektar 100 negatives processed about 18 months ago (they have sat untouched due to a house move). The images are very unsaturated and not 'Ektar' like at all. I scanned a couple and they look rather 'muddy' and desaturated. Deep blue skies are lighter than expected and tending towards cyan. My guess is the bleach wasn't run to completion for some reason.

FYI the film, C41 chemicals, RA4 chemicals and colour paper were/are all fresh. The C41 development was standard Kodak routine at 100F in a Jobo. The Fuji Crystal Archive paper was processed with Kodak RA4 chemicals at 35C in a Nova tank.

To give a sense of what the sheet looks like in real life, I'd estimate the attached photo has 50% more saturation than the print.

So, my questions:

1. Could there be any other explanation?

2. Is it worth running the bleach and fix again, even though the negatives are 18+ months old?

3. Can I run the bleach and fix in trays in daylight? (they are cut strips, so awkward to load back onto reels). If not, how about a combined blix?

Thanks

FujiLove · Feb 14, 2018

Here's a better image. I've desaturated my iPhone snap to closely match the print:

Young He · Feb 14, 2018

Looks normal to me; but I’m not very good at judging pictures. It might be worth a try to re- bleach and fix the negatives, but I think the desaturation is because of the Fuji paper. Some people have said that Ektar prints pretty badly on Fuji ca, and the paper isn’t very saturated.

FujiLove · Feb 14, 2018

Young He said:
Looks normal to me; but I’m not very good at judging pictures. It might be worth a try to re- bleach and fix the negatives, but I think the desaturation is because of the Fuji paper. Some people have said that Ektar prints pretty badly on Fuji ca, and the paper isn’t very saturated.

Thanks for the input, but these are definitely not 'normal' for Ektar printed on Crystal Archive. I've also read a few comments about Kodak film + Fuji paper, but I've printed a fair few using this combination before and the saturation is always much higher than this.

Any idea about question 3?

FujiLove · Feb 14, 2018

Here's what the linear scans look like (first two), compared to a roll of Portra 400 that look normal to me.

pentaxuser · Feb 14, 2018

When were negatives 3 and 4 processed and were they processed in the same make of chemicals as the first two? I had always thought that Kodak C41 chemicals had separate bleach and fix. Is this the case here? RA4 has blix as standard anyhow but there are those who believe that blix in C41 has risks unless it is very fresh but if you stuff was C41 blix then even PE, our Kodak engineer, admits if I recall correctly that blix is OK if completely fresh. I am not sure how many times C41 blix can be used before he believes that its efficacy may be compromised. If of course it was separate C41 bleach and fix and was fresh then it would seem that further "dunking " will not achieve any improvement.

Have you prints from Kodak RA4 chemicals taken on Ektar but processed on Kodak paper to compare? The scenes are not the same but have you got contact prints from negs 3 and 4 processed in the same RA4 chemicals as your contact you have shown us?

There is a lot of variables here and we will all come up with solutions but until we can narrow down causes we may not get anywhere

pentaxuser

FujiLove · Feb 14, 2018

I processed the dodgy negatives myself using Rollei/digibase C41 chemicals with separate bleach and fix. The other negatives shown above were processed by a commercial shop. Having said that, I’ve not had this issue before using the Rollei chemicals. I think I may just have forgotten to aerate the bleach and not run it long enough.

Unfortunately I only have Ektar negatives printed on Fuji paper...but they look fine regarding saturation and contrast.

pentaxuser · Feb 14, 2018

I think your second para in #7 rules out Fuji paper as the cause. The same type of film processed by you in one instance and commercial lab in the other suggests to me that either the Digibase chemicals were faulty or as you have said the bleach stage was too short and/or not aerated enough

I will rely on others to say if fresh bleach now can do anything once the negs have been fixed. For what it is worth there was a long thread on Digibase some years ago and the conclusions was that the Digibase instructions on the bleach time was way too short. I wrote down what the consensus was on bleach time and it was 6 mins 30 secs with a 4x 30 secs wash followed by a 6mins 30 secs fix.

The whole process was almost 24 mins which does seem a long time but presumably results in a real "belt and braces" process.

I have what I think was the best practice consensus in my note book and will repeat it here if anyone wants me to

pentaxuser

belichten · Feb 14, 2018

pentaxuser said:
I have what I think was the best practice consensus in my note book and will repeat it here if anyone wants me to

pentaxuser

i am interested in the practice, does it work only for digibase or all c41 chemiclas

pentaxuser · Feb 14, 2018

belichten said:
i am interested in the practice, does it work only for digibase or all c41 chemiclas

Not sure about all C41 chemicals and for instance in certain C41 chemicals packs, there is no separate bleach and fix steps so not all the steps below will apply. The reason why I have noted all the contributions to the Digibase process is that a number of people pointed out that the Digibase instructions did not seem to be complete or times were short. Hopefully this is the complete list and represents, for Digibase at least a complete and hopefully foolproof way of processing C41 colour negative film.

Step 1 Pre-wash 2x 30 secs( ideally the water should be at or slightly above development temperature to get film to the right temperature)
Step2 Develop(100F or 38C ) 3 mins 15 secs
Step 3 Stop 30 secs( if processing on a rotary processor, hand inversion is advisable here due to a gas build up and tank cap blow off)
Step 4 Bleach 6 mins 30 secs
Step 5 Wash 4 x 30 secs
Step 6 Fix 6 mins 30 secs
Step 7 Wash 4 x 30 secs plus 2 x 1 min
Step 8 Stabiliser 1 min

I hope this helps

pentaxuser

Rudeofus · Feb 14, 2018

I can't comment on the images, but there is a simple way to determine whether rebleach/refix is necessary: most film scanners also support an IR channel, and if your scanner software allows extraction of that channel, you know right away what's going on. Remember, that film dyes have density only in visible wavelengths, whereas silver is also opaque in IR wavelength range. If you IR channel reports more less than 80-90% translucency, there's a good chance you have silver or silver sulfide in your film, and at least the first can be treated by rebleach&fix.

FujiLove · Feb 14, 2018

Rudeofus said:
I can't comment on the images, but there is a simple way to determine whether rebleach/refix is necessary: most film scanners also support an IR channel, and if your scanner software allows extraction of that channel, you know right away what's going on. Remember, that film dyes have density only in visible wavelengths, whereas silver is also opaque in IR wavelength range. If you IR channel reports more less than 80-90% translucency, there's a good chance you have silver or silver sulfide in your film, and at least the first can be treated by rebleach&fix.

That’s a great tip. I’ll give that a go in the morning. I assume you meant less than 80-90% translucent?

Also, any idea whether I can run the bleach and fix in a tray? (Or blix if that makes a difference).

FujiLove · Feb 15, 2018

pentaxuser said:
Not sure about all C41 chemicals and for instance in certain C41 chemicals packs, there is no separate bleach and fix steps so not all the steps below will apply. The reason why I have noted all the contributions to the Digibase process is that a number of people pointed out that the Digibase instructions did not seem to be complete or times were short. Hopefully this is the complete list and represents, for Digibase at least a complete and hopefully foolproof way of processing C41 colour negative film.

Step 1 Pre-wash 2x 30 secs( ideally the water should be at or slightly above development temperature to get film to the right temperature)
Step2 Develop(100F or 38C ) 3 mins 15 secs
Step 3 Stop 30 secs( if processing on a rotary processor, hand inversion is advisable here due to a gas build up and tank cap blow off)
Step 4 Bleach 6 mins 30 secs
Step 5 Wash 4 x 30 secs
Step 6 Fix 6 mins 30 secs
Step 7 Wash 4 x 30 secs plus 2 x 1 min
Step 8 Stabiliser 1 min

I hope this helps

pentaxuser

Slightly off-topic, but Jobo recommend dry heating the tank and film for 5 minutes, rather than introducing water at the beginning. I.e. rotate the tank with film loaded in the water bath. I'm sure I read somewhere on here that pre-wetting colour film can lead to uneven development and streaking, so I've always avoided it.

Rudeofus · Feb 15, 2018

FujiLove said:
That’s a great tip. I’ll give that a go in the morning. I assume you meant less than 80-90% translucent?

Yes, that's what I meant. Sorry for the confusion.

FujiLove said:
Also, any idea whether I can run the bleach and fix in a tray? (Or blix if that makes a difference).

This should work. Make sure you don't shine too much blue or UV light on your negs between bleaching and fixing, or you may end up with printout silver. Maybe switch to red dark room light just from the last minute in bleach, all the way through wash until first minute in fixer, everything else can be done in broad daylight.

FujiLove · Feb 15, 2018

Rudeofus said:
Yes, that's what I meant. Sorry for the confusion.

This should work. Make sure you don't shine too much blue or UV light on your negs between bleaching and fixing, or you may end up with printout silver. Maybe switch to red dark room light just from the last minute in bleach, all the way through wash until first minute in fixer, everything else can be done in broad daylight.

The IR channel is showing 15%-20% density, so it looks like I have retained silver. Time to buy some C41 chemicals and run the bleach fix again I think.

Thanks for the information about the light. Would that be the same if I used blix instead of separate bleach and fix?

Rudeofus · Feb 15, 2018

FujiLove said:
The IR channel is showing 15%-20% density, so it looks like I have retained silver. Time to buy some C41 chemicals and run the bleach fix again I think.

Even if it doesn't help it won't hurt. Maybe rebleach/fix one test strip first, wait for it to completely dry, then measure again whether you see a difference. It could well be that 15-20% is already perfect and your scanner reports slightly different numbers than mine (Epson V700), or that the retained silver has already formed Silver Sulfide which won't go away with rebleach/fix.

FujiLove said:
Thanks for the information about the light. Would that be the same if I used blix instead of separate bleach and fix?

With BLIX there is no stage with Silver Bromide, therefore light should be less of an issue.

FujiLove · Feb 15, 2018

Rudeofus said:
Even if it doesn't help it won't hurt. Maybe rebleach/fix one test strip first, wait for it to completely dry, then measure again whether you see a difference. It could well be that 15-20% is already perfect and your scanner reports slightly different numbers than mine (Epson V700), or that the retained silver has already formed Silver Sulfide which won't go away with rebleach/fix.

With BLIX there is no stage with Silver Bromide, therefore light should be less of an issue.

Think I'll give it a go with blix. And yes, I'll try one strip and see how it looks.

BTW, the reason I'm asking about blix is I don't have any C41 chemicals right now, and no need to develop many colour films for a few months. But I can pick up a cheap 1 litre C41 kit with blix just to carry out this job and run the one film I do have queued up. I generally much prefer a two part bleach fix.

Thanks again for the help with these. They are negatives from a memorable trip to Iceland, from which I'd planned to print my own photo books. They are totally printable, but I want to make sure they are as good as they can possibly be for this little project.

pentaxuser · Feb 15, 2018

Good point about the "dry heat", FujiLove. Let us know what improvement the re-blix makes. Thanks

pentaxuser

FujiLove · Feb 15, 2018

My C41 chemicals are on their way. I'll update this thread when I've had a chance to re-bleach/fix a test strip.

Re-bleach/fix colour negatives?

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