salvaging under processed images

[Doremus Scudder]

I'm going to chime in and suggest bleach/redevelop as well. The trick is to use a staining developer like PMK or Pyrocat, etc. (any pyrogallol or catechol staining developer will work). Selenium intensification works, but will only get you 1/2 to maybe 1 paper grade difference if you're lucky. Then the other methods won't work...

I've had very good luck salvaging underdeveloped negs with bleach/redevelop. The process seems to add quite a bit of shadow detail that I though would go lost as well.

Here's my method, adapted from my personal darkroom guidebook:

"This method adds contrast to negatives that need more density, whether developed in a staining developer or not to begin with. This is a two-step process: first, bleach the negative to completion in a rehalogenating bleach, then redevelop it in a staining developer. All the steps can be carried out with lights on.

1. Presoak the neg for about 3 minutes.

2. Bleach the neg in a rehalogenating bleach until the image is completely gone and then a bit to be safe (formulae below). If you've used a staining developer to start with, a very faint residual stain image will remain.

3. Rinse the bleach off (I use the water-soak tray) then redevelop in the staining developer of your choice (I use PMK). Time is not critical, but it is important to develop the negative to completion, so leave it in the developer a few minutes longer than the recommended normal to be safe."

This process increases contrast by the amount of stain deposited in addition to the original, redeveloped silver image. As mentioned above, it can be repeated, although I have never had to.

There seems to be a number of ferricyanide/bromide formulas that range from 15-50 grams/l of the two bleaching ingredients with or without other ingredients. Some use the Bleach A from a sepia toner. Strength of the bleach just affects bleaching speed. I had good results with:

Potassium ferricyanide 20g (200ml 10% solution)
Potassium bromide 7g (200ml 3.5% solution)
Water to make 1 liter

If I'm just doing one or two 4x5 negs, I usually divide this recipe by four and just make 250ml.

I keep 10% ferri and 3.5% bromide solutions handy for this and other uses (SLIMT, etc.), but you can make up what you need from scratch easily enough. Don't toss the bleach after use; save it and use it for the next time you need bleach/redevelop. If not contaminated, it keeps a long time.

Best,

Doremus

[Jim Jones]

I haven't tried making a diapositive on high contrast film, but would consider it as a last resort. A copy camera would be preferable to contact printing to reduce artifacts induced by a contact printing frame.

[esearing]

Doremus Scudder (and others)- Thanks for the detailed instructions. Do I fix again after redevelopment?

I found a similar bleach formula at PF Reducer IV kit and ordered it. The bulk chemicals were a bit much for my needs.
This also gives me an excuse to try Pyrocat which I have wanted to do for a long time being a fan of Sandy King's writings and work.

[Doremus Scudder]

Doremus Scudder (and others)- Thanks for the detailed instructions. Do I fix again after redevelopment?

My pleasure.

There's no need to re-fix after redevelopment, but a good wash is still needed.

Doremus

[Gary Beasley]

I would definitely skip the fix if you ever plan on redoing the redevelopment cycle.

[esearing]

OMG & WOW!!! - I salvaged 4 negatives so far using bleach and Pyrocat HD and they have gone from so thin you could barely see the rebate to having deep rich detail. Only one lacks real contrast and it maybe that there was not enough contrast in the image to begin with. (shot at top of cling mans dome with weak clouds). I will post some before/after shots later in the week.

Anyone who has thin negatives should try this. It is easy and fun to watch the image disappear and reform before your eyes. The most nerve racking part for me was mixing the raw chemicals with all the warnings. Of course the final proof will be to see how they hold up when printing but that is true for all my images.

EDIT:
Used PF Reducer IV for the bleach, and PF Pyrocat HD. about 2-3 minutes in the bleach, rinse 2-3 minutes, PyroHD 11 minutes.

[Gary Beasley]

Good! Love to see what you get, so post a few when you get them done.

[Pierre 2]

Also looking forward to the results.

As a side note, I believe that I read recently on the forum that one used to collect old (constantly replenished) developer for some kind of silver plating of negative thin negatives. Anyway, that is what I maybe mistakenly understood as this scenario was not presented in this discussion. If that is indeed possible, would be interested in hearing of that process as well. Thanks !

[Bruce Watson]

Yes, I hate to admit it, but I used TableSpoon measure instead of Ounce measure. So I had about 1/2 the HC-110 needed. Some of the sheets did get a minute longer of devlopment and they seem the most salvagable. Contact prints don't have much detail though.

Use metric and you won't be making silly mistakes like this. No, I'm not kidding. The rest of the world went metric decades ago. This only happens in the USA any more. The other non-metric countries (there's two others still?) don't have much of an LF population.

[Bruce Watson]

would scanning them reveal whether it is worth the effort to try something like toning the negatives?

Probably not. But drum scanning them might well exceed what you can get from chemical reprocessing after you've flushed the latent image -- you did fix it, yes?

Most people think that drum scanning is only good for reading through high density. People who think that don't know drum scanning. Drum scanners shine with thin negatives. Ask Lenny Eiger. He's a LFPI member, a regular contributor, and an excellent drum scanner operator.