Reversal processing for black and white films

LucisPictor · Expire: 2013-12-03

http://www.leicapages.com/techniques01.html

Pretty interesting...

marty · Joined: 09 Apr 2009 Posts: 767 Location: Italy

Seele · Joined: 17 Apr 2009 Posts: 741 Location: Sydney Australia

This is pretty standard procedure, it is best to use a medium speed film such as TMX, Delta 100 etc; faster films tend to give very flat transparencies.

alex · Joined: 18 Apr 2009 Posts: 561 Location: UK

I used this technique many years ago, when I worked in a medical research laboratory. We used it when preparing slides showing graphs and charts, or illustrations taken through microscopes. I remember that the second exposure was not too critical, and we tended to use the Paterson-type plastic reels rather than the steel spirals, as you didn't needed to unreel the film from the plastic reels, since enough light got through to do the necessary, whereas the steel spirals could still offer sufficient block to ambient light. It's not a difficult technique to master, it's just a question of learning how to be methodical, and once you master than, the results are reliable.

As it was mostly charts and things, the film used was generally either Pan F, or the now long-discontinued Micro Neg Pan, an Ilford film with a nominal speed of 4 ASA (yes, that's 4).

Seele · Joined: 17 Apr 2009 Posts: 741 Location: Sydney Australia

Alex,

The second "fogging" exposure is only for rendering the residual silver halides to be able to get developed out to form densities, certainly you can use a chemical fogging agent for that purpose if so desired.

After processing the transparencies can be further treated, such as stabilised by using something like Sistan, or toned for stability and/or creative purposes; a slight treatment in selenium gives rather pleasant results.

alex · Joined: 18 Apr 2009 Posts: 561 Location: UK

Interesting, I hadn't thought of toning treatment ; largely I suppose because my use of monochrome reversal was entirely for scientific rather than aesthetic purposes. Nevertheless, I'm inspired to perhaps have another go at it for photographic pleasure purposes. When I did do it, I did it so often I didn't have to go to the recipe, but years later, I'd almost completely forgotten how to do it, so never did it again. The links given are so close to what I remember, that I'm going to see about getting the odds and ends of chemicals I don't already have.

Once a year, my family (brothers and sisters, that is) gets together for the weekend, and usually I bring a bunch of slides from my four decades long collection. One of the great things about slides, quite apart from their fabulous effect for projection, is how social they are as a way of looking at photographs. It's much easier to get 'oohs' and 'aahs' and 'I remember thats' from slides on a screen than it is from an album passed round.

Seele · Joined: 17 Apr 2009 Posts: 741 Location: Sydney Australia

Alex,]

The method on that webpage is pretty standard, you can also use PQ Universal as first developer, 1:6, for 8 minutes, try rating FP4 at ISO160.

For structured-grain films such as Delta 100 and TMX I tend to mix the solutions from scratch following Hans F Dietrich's method which proves to be very consistant and reliable. Worth investigating!