Bleaching Lippmanns?

Tom B. · Post by **Tom B.** » Sat Jan 14, 2006 6:21 am

Is it usual to bleach Lippmann photos after development? I can see that on the one hand it should reduce obscuration of deeper fringes to produce more saturated colors and maybe (with rehalogenation) increase diffraction efficiency, but on the other hand there would be lower contrast due to added noise and the fringes are unlikely to be very deep anyway. What do contemporary Lippmannographers do?

Martin · Post by **Martin** » Sat Jan 14, 2006 9:05 am

Tom B. wrote:Is it usual to bleach Lippmann photos after development? I can see that on the one hand it should reduce obscuration of deeper fringes to produce more saturated colors and maybe (with rehalogenation) increase diffraction efficiency, but on the other hand there would be lower contrast due to added noise and the fringes are unlikely to be very deep anyway. What do contemporary Lippmannographers do?

I'd also like to know more about what contemporary LIPPMANNOGRAPHERS (I like the name!) do. Hopefully this forum will make them participate here.

I do know that certain former Lippmannographers used to bleach their photos with mercury chloride. I gathered this kind of bleach might considerably alter the form and shape of the grains. Cajal seemed to have pointed out it played an important role in the creation of whites. But frankly, I don't know. And I definitely decided to keep my hands off mercuric stuff.

Given the extremely thin fringe structure I assume great care had to be given to the bleach formula. There's always a risk the bleach will attack the image.

Very likely, the “Russian” method, that's to say using solution-physical development, might be easier.

Tom B. · Post by **Tom B.** » Sun Jan 15, 2006 6:38 am

Martin wrote:Very likely, the “Russian” method, that's to say using solution-physical development, might be easier.

I still have some GP-2 in the fridge to try... I experimented with it a year or two ago with PFG-03C for Lippmanns and don't remember it working any better than other developers but I was fascinated by the beautiful silvery edges it produced in some of my test plates from metallic silver plating out...

Martin · Post by **Martin** » Sun Jan 15, 2006 9:40 am

Tom B. wrote:
Martin wrote:Very likely, the “Russian” method, that's to say using solution-physical development, might be easier.
I still have some GP-2 in the fridge to try... I experimented with it a year or two ago with PFG-03C for Lippmanns and don't remember it working any better than other developers but I was fascinated by the beautiful silvery edges it produced in some of my test plates from metallic silver plating out...

It may turn out that hydroquinone based developers are not the best way of developing Lippmann emulsions. Maybe the issue is in-depth-development vs. surface-development.

I don't know for sure if the “orthodox” developers based on either pyrogallol or amidol really behave differently in that respect though.