Tasma Positive GOST6 BW, how to develop it?

[narigas2006]

Hi all,

I have some film called TASMA (From the former USSR) iso 5 I think and positive. in fact the emulsion is totally white. Can I develop it as a negative? Otherwise, could I use the normal bw reversal process? Many thanks.

richard

 

[PHOTOTONE]

I'll bet that is like the old Kodak Fine Grain Release Positive, which is a blue sensitive emulsion designed to make positive transparencies from b/w negatives. Not normally a reversal material. It would probably be developed similar to a b/w print. You would contact print a negative onto it.

 

[glennfromwy]

That's what it sounds like to me, too. I assume it's 35mm. The direct positive film has a crystal clear base and was used for high speed contact printing motion pictures for release. If that's what it is, it's almost grain free and very sharp. You can use it as a negative film. It was meant for rapid processing in an active developer similar to Dektol (about 3 min.). You will get a longer scale if you use something like D-76 !:3.
It could also be a medical imaging film, which is pretty similar. Try it and see.

 

[srs5694]

I bought some of what may be the same stuff a while back. It's called Tasma MZ-3L (this looks like "M3-3A", where the "A" lacks the cross-bar; it's a little like a Greek "pi" or an upside-down "U"). Mine came with an instruction sheet in Russian with a developer formula:

phenidone: 0.1g
hydroquinone: 2.2g
sodium sulfite (anhydrous?): 16g
sodium carbonate (monohydrate?): 22g
potassium bromide: 4g
water to make: 1l
Dilution ratio: 1+0
Development time: 2-4 minutes @20C

I tried using this formula, except that I substituted the appropriate amount of sodium ascorbate for the hydroquinone because I didn't happen to have any hydroquinone at the time. I also tried using Rodinal 1+25 for 4:15. Both developers worked, but I can't say how well because my sample rolls were badly out of date and, I suspect, were poorly stored. The resulting negatives had huge amounts of base fog, as well as splotchy marks that I suspect might have been caused by the emulsion peeling away from the film in sections. I'd be lucky to get one decent negative out of a roll of the lot that I got. Still, those development times were about right. (I used 3:00 for my tests of the ascorbate variant of the MZ-3L developer.)

FWIW, this film isn't really a positive film per se; my understanding is that it was meant to create positives by contact-printing negatives, say of microfilm negatives or the like. I suppose you could always try it in a reversal process, if that's what you want. My understanding is that it's an orthochromatic film, and my negatives looked that way (the red parts on a box of Rodinal I shot as a test looked nearly black).

In any event, I hope yours is in better condition than mine!