Since he did not reply personally, I would like to advertise the image athiril posted in the experimental gallery: Portra 400 @ ISO 25600. This film is truly impressive and made me buy 10 rolls of color negative film and a developer kit again after years of E6 and B/W.
Trying to be the best of whatever I am, even if what I am is no good.
No you don’t change a thing. I run it normal if i shoot from 200 to 1600. I would also run it normal if I went down to 100 possibly 50. I will do some testing for my self though. If I shoot at 3200 I push one stop in processing and 2 stops for 6400.
same ^. I don't tell my lab anything and just let them develop normally usually. I've done this for a roll where I experimented and shot all over, ISO wise, and gotten the results I want. I think of the new portra this way: overexpose and you get the creaminess that was inherent with NC, underexpose and you get a little more punch in contrast and color like VC had.
My initial experiments with it were somewhat less than scientific however I think I determined well enough for myself that this film can handle anything I want to shoot color negative for.
There was a strange phenomenon though, something I haven't seen before: On only one of my rolls that I shot at 800-1600 there were huge color shifts. Things that were lit with fluorescent were magenta. It was odd because I have shot portra 400 at 800 and 1600 before without problems.
cjbecker and rphenning: thanks! I am excited now. I process C-41 at home and will use the same times no matter what ISO I meter at. Now the only thing I have to learn is how to take some nice compositions as were displayed on this thread. :-)