Thursday, January 28, 2010

Interesting tidbit about 55 emulsion

Scanning through the discussion groups, I ran across this post about type 55 being Panatomic X emulsion.  The Post is from Tim Summa and I would like to contact him once I figure out how (not easy with these forums - anybody? hmmm nice images! wow)

Old Panatomic X image shown above, as I recall.  Hard to remember decades back.

Anyway, I was just comparing some 55 today to that very sheet film, which I have in an old moldy expired stack, and it is not the same overall thickness (Kodak is thicker) but maybe the emulsion is the same.  From the Monobath Manual I learned that it is possible to make a very good monobath for Pan X, but the remaining problem was getting the silver out.  That's easy because of the discovery of Rott.  I see.

Very interesting.  It is all clicking today.

Now, on to studying pods. Actually I want to avoid pods altogether and have been thinking along the lines of a water-activated hydrogel monobath. The result would be the same (so I imagine, possibly naively) as spreading the layer of goo. Still, all those rollers are out there, most in perfect shape. I counted about a dozen Land patents focusing on the rollers - it seems to me that making the chemicals spread evenly and consistently was the single most important enabling technology in early Polaroid, and maybe everything later too.  There are lots of details about spreading viscous liquid mixtures in thin layers at various speeds - something that modern rheology might well revisit.

There are a lot more options available today - micro encapsulated solutions are all over the industrial landscape, for instance.  OK I have to get over my Pod/Goo phobia, and start reading.


gerald said...

hard to say if it was the same exactly. it probably was in the beginning, and later was at least based on it. thing is: the haptics are very close, and this is an, if not the most, important point of 55. it's not only about 'one' negative. it's about 'the' negative.
as panatomic-x was discontinued long ago, photographers used 55 even just for the neg. they were not interested in the pos or the instant at all.
it's the greys, the unbelievable sharpness (no way a 'neg' of a bleached fuji can reach that just a tiny bit. it's just a transparent paper-negative, not a real negative!), the unique way the material can solarize.

to save you some time clicking:
(at the bottom and around)
(at the bottom, by 'wirehead'
(at the buttom, 'bite the dust')

Anonymous said...

There is a paper somewhere on the Web, written by a woman interning at Polaroid, about the problems of getting even developer spread in 500 materials, which bend the picture unit through 180 degrees during development.

Bob Crowley said...

Thanks, I'll search for it - let me know if you find it first!

Bob Crowley said...

I think I found it, Diana Garcia, MIT, about captiva integral film and roller kinetics. Does that sound right?

Anonymous said...

There ya go. Tell Timmers King Anthony gave you his email.