Reciprocity for Adox CMS 20 II

[Sal Santamaura]

I haven't done extensive testing like I usually do, but this data seems to give me decent results. I've not adjusted development times.

1 sec give 1/3
2 sec give 1/3
4 sec give 2/3 or 1.5X
8 sec give 1 stop or 2X
15 sec give 1 1/3rd stop or 2.5X
32 sec give 1 2/3rd stop or 3X
64 sec give 2 stops or 4X

My data is as follows: at 1 second I give a third stop more. 2 seconds becomes three seconds (or 2/3rd stops), 4 seconds becomes 6 seconds...

Have you changed the two second adjustment based on experience over the last couple of years?

 

[Andrew O'Neill]

Have you changed the two second adjustment based on experience over the last couple of years?

Yes. I've tweaked it a bit after quite a bit of field work. Your data would probably work perfectly fine for me . Sal, are you going to stock up on this film (assuming you don't have a stash already)? I'm debating whether or not, to beef up my tiny stash (of 35) or just start playing around with their HR-50, of which I recently received several rolls...

 

[Sal Santamaura]

Yes. I've tweaked it a bit after quite a bit of field work. Your data would probably work perfectly fine for me . Sal, are you going to stock up on this film (assuming you don't have a stash already)? I'm debating whether or not, to beef up my tiny stash (of 35) or just start playing around with their HR-50, of which I recently received several rolls...

I'm not a prolific shooter, so the 20 rolls I bought two months ago from Freestyle (at $6.49 each!) will probably serve this septuagenarian as a "lifetime" supply. The only concern I have is ongoing availability of Adotech IV. Which means I'll likely eventually be researching some of your posts here about other developers for this film.

In January I also stocked up on SCALA 50 / HR-50 (they're the same film, save for packaging and edge markings). My first test roll was developed in FX-39 II, which seems like a product that will be around for a long time. Later I got some HR-DEV; resulting curve shape was the same, but speed increased around 1/3 stop. Grain and resolution of HR-50 are not up to the standards of CMS 20 II, but then again I get an honest EI 25 out of it in HR-DEV, compared to EI 6 for CMS 20 II in Adotech IV. The biggest difference between them is that HR-50's curve flattens out starting at Zone V and never goes higher than Zone VII; it has absolutely no separation above that. CMS 20 II is much more linear, with a gentle break at Zone VI and continued (although reduced) separation up through at least Zone IX, which is where I stopped measuring.

In my experience, one must use a glass negative carrier with both these films. They're just too curly otherwise.

 

[Andrew O'Neill]

I'm not a prolific shooter, so the 20 rolls I bought two months ago from Freestyle (at $6.49 each!) will probably serve this septuagenarian as a "lifetime" supply. The only concern I have is ongoing availability of Adotech IV. Which means I'll likely eventually be researching some of your posts here about other developers for this film.

In January I also stocked up on SCALA 50 / HR-50 (they're the same film, save for packaging and edge markings). My first test roll was developed in FX-39 II, which seems like a product that will be around for a long time. Later I got some HR-DEV; resulting curve shape was the same, but speed increased around 1/3 stop. Grain and resolution of HR-50 are not up to the standards of CMS 20 II, but then again I get an honest EI 25 out of it in HR-DEV, compared to EI 6 for CMS 20 II in Adotech IV. The biggest difference between them is that HR-50's curve flattens out starting at Zone V and never goes higher than Zone VII; it has absolutely no separation above that. CMS 20 II is much more linear, with a gentle break at Zone VI and continued (although reduced) separation up through at least Zone IX, which is where I stopped measuring.

In my experience, one must use a glass negative carrier with both these films. They're just too curly otherwise.

Thank you, Sal. That's very useful information.