Rollei RPX 25 and Perceptol

tho60

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I would like to develop Rollei RPX 25 film in Perceptol to gain the finest grain possibile. Have you tried it? How about my idea? I fear that I will get underdeveloped negatives, because RPX 25 is quite slow film and Perceptol even reduces film speed.:(
 
I would like to develop Rollei RPX 25 film in Perceptol to gain the finest grain possibile. Have you tried it? How about my idea? I fear that I will get underdeveloped negatives, because RPX 25 is quite slow film and Perceptol even reduces film speed.:(

How fine grained are you after? I've only ever developed it in Rodinal, and I couldn't see any grain on my scanned images. It looked kind of odd with no grain!
If you're worried about film speed, why not just expose it at an EI 12 or so?
Best of luck!
 
How fine grained are you after? I've only ever developed it in Rodinal, and I couldn't see any grain on my scanned images. It looked kind of odd with no grain!
If you're worried about film speed, why not just expose it at an EI 12 or so?
Best of luck!

RPX has quite a high contrast in Rodinal even at 1:100 or 1:200 dilution. I am looking for the finest grain with moderate contrast possible.
 
You could run a roll with some bracketed exposures to insure a more printable negative, if you don't have time for full testing.

If you've already exposed the film I'd add 10 or 20% to the suggested time as some insurance. Massive Development Chart lists 10 minutes for Perceptol 1:1, I would choose 11 or 12 as a starting point, and keep the agitation to gentle, once a minute.
 
I develop all my films In Legacy Mic-X which is very similar to Perceptol.

I would add a full stop, or even a bit more. After a roll or two you should be able to dial it in.

I prefer the tonality this way. Can't say I've tried your film but just do a test roll and see.
 
if you've already shot it then it won't matter to add more time to the dev. It's already potentially underexposed in the shadows.

I'd think a 25 ISO film would be pretty fine grained already, indeed. But yes you'll want to add a stop or so of exposure in Perceptol. I found TXT to be about 200, for instance, in Perceptol 1+0.
 
The only other point I will add is, that my development times can be quite long. In the colder times in my basement darkroom it can go down to 15C. My development times have gone as long as 30-35 minutes in stock solution. And I am rolling the JOBO tank on a Unicolor Uniroller for constant agitation.

If the film responds well to the developer, you may really like the results :) Good Luck
 
With Perceptol 1:0 you will have some speed loss if you shot it at 25 ISO. To keep the speed with a modest boost in grain use Perceptol 1:1 although as most will tell you the grain boost will be very slight
 
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