in that case, getting great results with a non-standard process on the first attempt seems to me risky and not really worth it unless it's for the thrill of it.
Again, if someone wants to offer this as commercial service, then this doesn't seem to be the first roll he's ever developed. E-6 FD diluted 1+9 is a very capable B&W developer, and since it doesn't have to maintain three color layers in lock step for this, we have a lot more leeway here in B&W than the E-6 folks. This makes this developer so advantageous for those, who do both E-6 and B&W: first we develop color slides, then the FD is reborn as very capable B&W developer - for free!
if the question was about how to do high volume processing of b/w cheaper with E-6 developer, that is another matter. I still wonder how much money one could save that way, considering that there are a lot of rather affordable b/w developers.
Nobody expects to start "high volume processing" for B&W these days. Even cheap B&W developer must be bought, whereas that E-6 FD seems to be already there. It's a synergy effect well worth looking at.
that's very interesting - would be great to see a controlled comparison.
has anybody done that?
I have been using E-6 FD diluted somewhere between 1+4 and 1+9 for the last 10 years, mostly for slower film (Fomapan 100, Fuji Neopan Acros I/II, Kosmophoto, ...), initially also for faster film (Tri-X, Bergger Pancro Pancro 400, Delta 3200). I have done some speed tests with Tri-X back then, and it holds up well compared to Promicrol. I have never made strict side by side comparisons regarding grain&sharpness, but the negs and the resulting prints look good. Since the stock E-6 FD was optimized by Kodak for sharpness, I have no reason to believe, that a dilute version would suddenly forgo these great properties.
Since E-6 FD is very standardized, anyone with an E-6 kit can easily try it out, either with fresh dev, or after an E-6 test run has been completed.