Film intensification issue

[Terrence Brennan]

I am trying to intensify four rolls of film I recently processed. In total there were eight 35mm, 36 exposure rolls of Eastman Double-X 5222 film exposed in a single shoot. All of the rolls were exposed under identical conditions, that is to say, on a typical "sunny-16" day in Ottawa last week. The exposure was checked regularly, using my trusty Gossen Lunasix-3 meter.

They were exposed at an EI of 100, with an effective film speed (EFS) of 32, as I had #11 filters over all of the lenses, and the time in the developer was what I had calculated for an EI of 125, or an EFS of 40.

All of the rolls were processed four at a time in a Kinderman tank. I had a problem with the second batch of four rolls; they were thinner, and looked about a stop underexposed. Moreover, the fogged portion of the leader of the second batch was not as dense as the first four rolls, which made me suspect underdevelopment, rather than underexposure.

The Kodak publication, "Chemicals and Formulas," Publication J-1, has a section on intensifying negatives. The formula I looked at was KODAK Chromium Intensifier In-4, which I didn't want to use, as it requires potassium dichromate, a really nasty and bad for the environment chemical.

I had a look at the Ilford publication about reversal processing, and found another choice, which used 2g/500ml of potassium permanganate plus 10ml/500ml of sufuric acid, when mixed together make 1 litre of bleach. I have the potassium permanganate, and after poking around a bit on the web, I found that the sulfuric acid can be substituted with 50g/500ml of sodium bisulfate, which I also have. I have seen a number of references to this formula on the web, which seems to be in use a a bleach for reversal processing of film.

I followed the instructions in the Kodak publication, except for the step where they recommend hardening the emulsion, as none of the references on the web make mention of this step when the above formula is used for reversal processing.

It bleaches the film in less than a minute, but after washing the film, and immersing it in fresh developer (Ilford 2000RT, at 2x the concentration recommended by the manufacturer), all I have for my efforts is a big nothing burger.

So where did I go wrong? Can any of the APUGers enlighten me on the error of my ways?

 

[Sirius Glass]

Would you please post photographs, not scans of the negatives?

 

[gone]

I would just do a test w/ a piece of the film. Develop it a little longer than normally, see what you get. Due to the nature of your problem, I would ONLY go by empirical evidence (what you see w/ your own 2 eyes after trying this or that w/ small samples).

 

[MattKing]

I trust that after bleaching you exposed the film to light before re-developing it.
When you describe the results, are you saying that you see no change, or are you saying that there is no image remaining?

 

[Patrick Robert James]

I believe you used a reversal bleach not a rehalogenating bleach. Permagnate removes exposed/developed silver from the film leaving the unexposed silver intact. When doing a reversal that is what you want, but for intensifying a negative you just want a "bleach" that rehalogenates the silver so it can be redeveloped. The fact that they are both called a "bleach" is confusing.

You won't be able to recover those negs.

 

[Terrence Brennan]

I trust that after bleaching you exposed the film to light before re-developing it.
When you describe the results, are you saying that you see no change, or are you saying that there is no image remaining?

There is a faint ghost of an image.

I wonderd, after the post, if I should have used a clearing bath after the bleach and a wash, as the film might have been a bit too acedic, which might have caused the develper to fail. I know that thw developer is good, as I put a small piece of scrap film in it before starting the test, and it was black after about a minute.

 

[Patrick Robert James]

I should add that in the future if you want to intensify a neg there are simpler ways. Selenium toning a neg will give you a boost in contrast. Bleaching with a Ferricyanide/Bromide bleach and redeveloping in a staining developer like Pyrocat or PMK will also give you a boost.

 

[Terrence Brennan]

I believe you used a reversal bleach not a rehalogenating bleach. Permagnate removes exposed/developed silver from the film leaving the unexposed silver intact. When doing a reversal that is what you want, but for intensifying a negative you just want a "bleach" that rehalogenates the silver so it can be redeveloped. The fact that they are both called a "bleach" is confusing.

You won't be able to recover those negs.

Arghh! I was trying out my tests on a few clips of film, not the whole roll, so the rest of the four rolls are intact.

I guess that I may have to mix the potassium dichromate/hydrochloric acid bleach and give it a try. VMT for the info on the difference between the two bleaches!!

 

[MattKing]

The bleach used for two part sepia toning is a re-halogenating bleach.

 

[Sirius Glass]

I should add that in the future if you want to intensify a neg there are simpler ways. Selenium toning a neg will give you a boost in contrast. Bleaching with a Ferricyanide/Bromide bleach and redeveloping in a staining developer like Pyrocat or PMK will also give you a boost.

I have used Selenium toning. It can help some negative, but a badly underexposed negative cannot be saved.

 

[Bill Burk]

Arghh! I was trying out my tests on a few clips of film, not the whole roll, so the rest of the four rolls are intact.

I guess that I may have to mix the potassium dichromate/hydrochloric acid bleach and give it a try. VMT for the info on the difference between the two bleaches!!

Yessss smart move. Another approach could be to try it all… not on what’s left of your rolls, but on new rolls ruined the same way ( e.g., work out the steps on fresh film).

 

[Raghu Kuvempunagar]

I believe you used a reversal bleach not a rehalogenating bleach. Permagnate removes exposed/developed silver from the film leaving the unexposed silver intact. When doing a reversal that is what you want, but for intensifying a negative you just want a "bleach" that rehalogenates the silver so it can be redeveloped. The fact that they are both called a "bleach" is confusing.

You won't be able to recover those negs.

There is a rehalogenating variant of permanganate bleach as well. It uses hydrochloric acid instead of sulphuric acid. When a negative or a print is treated with this rehalogenating permanganate bleach, silver is converted to insoluble silver chloride which can be redeveloped. Here is a formula from Haist:

Water: 750ml
Potassium permanganate: 0.625g
Hydrochloric acid: 10ml
Water to make: 1l

Test it on a scrap negative first if you intend to try this bleach. However, for the purposes of intensification, a rehalogenating permanganate bleach is not really a substitute for dichromate bleach as intensification critically depends on the image-wise deposition of a chromium compound in the bleached negative. A permanganate bleach won't be able to supply the chromium compound.

 

[revdoc]

You can probably replace the hydrochloric acid with acetic acid and table salt, which is what I do with dichromate intensifier. What matters is (1) low pH, to enable the bleaching, and (2) chlorine ions, so the silver bleaches to silver chloride, which can be redeveloped.

These intensifiers work by adding metal from the bleach to the redeveloped image. With dichromate bleach, they add chromium, and I assume that permanganate adds manganese.