Roman,
Thanks for the reply. This is information you didn't supply the last time we discussed Rodinal vs. R09 concentration, and I'm glad to see it. I haven't looked it up, but I think we got one or two other people who'd had the same impression as I had about the relative concentration of stock, and there were a number of folks on photo.net who also believed that. Since the availability of R09 has been limited in the US, very few of us over here have had much experience with it, and the available information is also limited.
I don't believe for a minute that I'm the final arbiter of what information is the best, especially when it's unsupported by documentation or testing, but I'm more convinced by the new information and sources you included here. But as you mentioned, the techniques used in the Agfa and Fotoimpex are different, and I don't recall having seen anything stating the target gamma from the sources other than Agfa, which makes comparison of published times/temps pretty much pointless. I'm sure you have better access to this kind of information than I, as much of that kind of information doesn't make it into English publications distributed here in the US. I appreciate your posting a summary here.
I have to admit that part of my skepticism about recommended development times from Agfa derives from the fact that their times have always been a bit long for me, even with a diffusion enlarger and taking the target gamma into account. That's combined with a stay in Bonn of one year (1982-1983) in which I saw a great preponderance of overdeveloped, very high contrast photography in publicly displayed work, which had no subtle midtones at all. That may have just been the current style, but it gave me a biased view of what "the average German photographer" (if we can posit such a thing) aimed for in processing. Obviously, the goals of Agfa's testing and technical department and the average photographer are not necessarily the same, but I became more skeptical of the manufacturers' recommendations as a result of the work I saw. Maybe it was folks who were printing 0.65 gamma negatives with condenser enlargers on grades 3 and 4.
I don't own a densitometer, but do reasonably well with a spotmeter, so I'll give that a go when I do get a chance to test. I'll likely do something like a 1:100 dilution with both developers and Efke 25 and same time/temp/agitation. This will only tell me how the developers compare for my typical usage, but should give a general comparison of activity levels. That's a little difficult for me to do right now, as I have no good temp control in my darkroom when it's summer, and the temps cycle by several degrees daily. Maybe I'll enlist my son to copy my handling for a simultaneous run.
Thanks for the additional information. Please let us know your results if you get a chance to make a comparison run under controlled conditions. I'm sure there are many people who'd like to see a well done comparison. Since the formulas are not exact duplicates at this point, I'd be interested in any other differences you note besides relative activity.
Have you considered adding sodium ascorbate to Rodinal to increase the gamma on FP4+? I've tried this with Rodinal and HP5+ and liked the results, however, I found I had a very slight preference for PC-TEA with HP5+.
Getting good info on R09 in the US is about as easy as finding a good Kolsch or Weizen.
Tschuss und danke,
Lee