"rescuing" grossly underdeveloped negatives - intensifier advice requested (UK)

[pdeeh]

In a moment of brain-fade last night, I over-diluted a batch of developer by a factor of 3 for a roll of 135.
Had I recognised what I'd done before it was fixed, I expect I could have extended the development time and perhaps rescued the situation, but I didn't.

Consequently I have ended up with a roll of negatives bordering on transparent. The edge markings and frame spaces are barely discernible.

I have scanned the roll and managed to extract something, and normally I would write this off to experience and move on, but there are two shots on this roll which I would particularly like to salvage further if at all possible.

I have "read up" what I can on the use of intensifiers, and realise that I can't expect much in the way of increased density with this particular situation, and that I can expect increased grain. The latter is no great concern.

I know I can make my own intensifier, and have found several formulae here at APUG from Ian Grant ... but don't have all the chemicals or a staining developer to hand (plus I would rather not have to buy rather expensive and toxic materials which I will likely use only once in a blue moon)

The choices of commercially easily available intensifiers in the UK seem to be Fotospeed Cl10, and the Speedibrews Chrome Intense and Speedintense. I can't seem to find much information about these, except that the Fotospeed product requires Dektol for the redevelopment step. Speedibrews website refers to the use of Speedintense for "grossly underdeveloped negatives" which is exactly what I have.

Is there anything others can add from experience of these products?

 

[Chamaeleo]

I used a chromium intensifier in the 1950s. I had no success at all with really thin negatives like yours. I never tried uranium, and the only reason for suggesting it is that the BJ Almanac (1956 edition) states: For 'ghost' neatives, uranium is admirable. The formula given is (in metric units):
Solution A: Uranium nitrate (23 g made up to 1 litre with water)
Solution B: Potassium ferricyanide 23 g made up to 1 litre with water)
For use, take 4 parts of A, 4 parts of B plus 1 part of acetic acid (presumaly glacial acetic acid). After intensification, wash in several changes of still water until the yellow stain is gone. A 2 per cent solution of ammonium thiocyanate will remove any yellow stain.
I do not know if any of the commercial intensifiers available in UK are of the uranium type or of similar effect.
Even if you go down this route, I would not hold your hopes of success high.

Uranium nitrate (uranyl nitrate) is available from chemical suppliers. It is a nasty as are many photographic chemicals but not radioactive, as any 1950s schoolboy would know. The minimum order I have found is £66 plus vat and carriage. Concentrated acetic acid (even if not the old 'glacial') and uranyl nitrate are available from chemical suppliers like Sigma-Aldrich. The other chemicals are in the Silverprint list.

Johnson's of Hendon made uranium intensifier see: http://bit.ly/VEywAW

You will see there that it was recommended for thin negatives. Somebody out there may have an old pack they would be willing to part with.

 

[pdeeh]

Thank you for this interesting information.
I had read references to uranium intensification but not that level of detail, so it's good to see it recorded. The Johnson's information site is a gem!

 

[funkydog]

Have them scanned with a good film scanner before going down the chemical intensifier route. You'll be surprised by what the scanner can dig out from underexposed negs.

 

[pdeeh]

yep, see my OP

I have scanned the roll and managed to extract something,

 

[MartinP]

The obvious sensible precaution for testing your eventual plan is to shoot and develop another roll, or half a roll etc, in the same way and then to do the test on the non-important roll - before applying the results to the original. The only thing I tried was Selenium, for a roll with accidental two stops under exposure and 'tired' developer. There was a slight increase in density which made it a little easier to print, but if there is almost no silver on the neg (in the shadows in my case) then not much can help. Good luck!

 

[Jim Noel]

The method I use is scary for those who don't have several years of experience. I have used it for more than 60 years and won't use any other. No increase in grain. It all can be done with the lights on.

Bleach and re-develop. You may bleach in what comes with sepia toner or make your own with ferricyanide and sodium thiosulfate.
Bleach until there is no image, or a very faint one.
Rinse well
Re-develop in your favorite developer. My choices are usually one of several pyrocatechin developers, but they are not necessary. Continue development until complete - in other words nothing more is happening.
Rinse, fix and wash as usual.

You can practice this with an underdeveloped print.

 

[Steve Smith]

Have them scanned with a good film scanner before going down the chemical intensifier route. You'll be surprised by what the scanner can dig out from underexposed negs.

You might also be surprised at what you can get out of them printing optically.


Steve.

 

[bdial]

....or make your own with ferricyanide and sodium thiosulfate.

Is't that farmer's reducer?

 

[henry finley]

Is't that farmer's reducer?

To my recollection, Farmer's Reducer WAS a feroicyanide based chemical, but in Kodak's miraculous chemical genius, was able to reduce disproportionately, the darkest first. Plain ferrocyanide reduced everything, especially the lightest first.

 

[Gerald C Koch]

Some people say that they have had success with repeated bleaching and redevelopment in a staining developer.

For intensification by redevelopment you want a rehalogenizing bleach. You certainly don't want to use any bleach that contains thiosullfate since this would destroy any image.

Chromium intensifier is not considered to be archival.

 

[henry finley]

I never had much come of the intensifier either.

 

[pdeeh]

All very interesting stuff.

As I have plenty of frames to "play with" from this roll, and as I coincidentally had some Ferricyanide arrive this morning (as I'm going to try some lith printing and wanted to be armed for two-stage), I thought I'd try a bleach and redevelop.

So I've just made a rehalogenating bleach stock of 7.5g/100ml each of Potassium Ferricyanide and Potassium Bromide, diluted some 1+9 and clipped three frames from the dead roll. I bleached this clip in a shallow tray with continuous agitation for about 5 minutes. There remained some image apparent, but mostly gone, including all edge markings. I chose these three frames as they had three sisters originally exposed within a few moments of each other, so I have a before- and after- comparison.

I then gave it a thorough wash.

Then I knocked up some print developer (this is Fotospeed's recommendation for redevelopment after using their Cl10, what the rationale might be I don't know but I thought I'd try it) and redeveloped the clip in that, again with continuous agitation in a shallow tray. Within 3 or 4 minutes there was noticeable redevelopment and a significant increase in density.

They are washing at the moment, and I'll check tomorrow to see how they look.

I wondered whether I'd get much more improvement from a commercial product?

 

[RalphLambrecht]

i'm sure if you buy these ingredients anywhere you'll end up on a list from several government agencies.plus, the stuff is right out dangerous in the wrong hands. i would write this off to fate and experience and move on.all the best.

 

[pdeeh]

With all due respect, only the uranium nitrate is not readily available from UK from photographic suppliers, as Chamaeleo pointed out in the first reply to my OP.

Many of the others mentioned in this thread are in the formulae for commercial photographic products, and Ferricyanide is often named in APUG threads as a component of bleaches.

In the process of not writing it off the experience, on this occasion, I am actually gaining experience and knowledge.

Consider - How did you gain your (considerable, judging by your work and publications) knowledge and experience?

 

[Gerald C Koch]

The funny thing (and government types miss this point) is that when you purchase uranium salts they are made from depleted uranium. What you get is only mildly radioactive and you cannot make a bomb from it. In this respect uranium nitrate is no more dangerous than lead nitrate unless you want to poison someone. Your local hardware store has many things which are just as dangerous and readily available.

 

[Rudeofus]

The trick about chromium intensification is that the chromium bleach builds up density while it bleaches, the development step afterwards recreates silver density while (hopefully) not removing chromium density. If you bleach with ferricyanide instead, then redevelop, you will not gain much.

Which brings up Ralph Lambrecht's point: Ferricyanide is mostly harmless, but Dichromate is quite toxic and overall nasty. Yet Fotospeed is apparently able to sell it without repercussions. I have read a lot about photographers being harassed by British/US police (or rent-a-cops) for taking pictures, but never for possession or use of photo chemistry.

 

[pdeeh]

ah thank you Rudeofus, that's a bit of information (about the chromium bleach) that I hadn't properly understood.

Reviewing the negatives this morning, there is a marginal improvement. Worth the effort to understand the process, but not significant enough to make much difference to a scan or print.

I think next time I need to order some bits and pieces I'll include some chromium intensifier and have another go. I'd still be interested to know more about the Speedibrews intensifiers.

It's not just Fotospeed by the way who are able to supply Bichromate. You can buy by the pound on eBay.