So, how did it all turn out . . .?
Got my Delta and DDX on Saturday. Shot a test roll, with frames exposed at 1600, 3200, and 6400.
Now, I'd read that this film benefits from being developed for 1 stop faster than exposed. For example, rate at 3200, dev for 6400. So I figured I'd do exactly that, on the basis that I'd either get good frames at 32K, or just possibly 64k would work.
Gave 12 and 1/2 minutes in 1+4.
First, the shots at 6400 were too thin to print comfortably. Those at 1600 had best density, but the highlights were just going too far, and would have benefitted from slightly less dev time.
The shots at 3200 really surprised me. Adequate density, a wee bit short of shadow detail by my usual standards, but easily printable. Very sharp. Full frame printed 8x8 inches showed amazingly little grain. I don't think any worse than 35mm HP5 rated at 400 and printed to the same size. Had I been given the prints to judge I don't think for a second I'd have guessed it came from a very high speed film.
As someone who mostly shoots 6x6 PanF, and FP4 in 5x4, this stuff is VERY interesting.
Next, I'll shoot a couple of rolls at 3200 to get a feel for it. Of course, the only way to find the limit is by going too far. At some point we'll have to try shooting REALLY fast and developing for half an hour. Just to see . .