Kodak Pro 1000
Like most film photographers, I have tried my best to collect as much film as I can. I got into the game later than I should have, and as a result, a lot of film stocks have been discontinued, which means the only way I can get and try them is through ebay or the like, and they are almost always expired or close to it.
I've taken quite a liking to kodak 100 prn, which is a "pro" film from them, which I believe was discontinued in 1998 because the latest I have found expired in 1999. I have about 25 rolls left and I love it, the colors are muted but nice.
Having gotten that, I also got a few packs of Kodak Pro 1000, which is a low light film rated at 1000iso. Lower ISO films break down much slower, and the general rule is to shoot a film a stop under for every decade it is expired; a film from 1999 I should shoot two stops under. The 100 speed I usually shoot at 80, and it seems to work just fine, but the 1000 speed I did not trust to shoot without testing, so that is exactly what I did.
I setup my GF670w on a tripod and shot the film at various speeds to see what results were the best, in this way I can shoot these rolls confidently in the field.
Each of these were scanned in with no edits or adjustments. I'm sure people will prefer one over another, I think I prefer the 200iso shot.
All the results would be "usable" but at 800 and above they are very underexposed. I would see shooting at 800 and pushing one stop in development, but I'm not sure I see the point when I could just shoot a more reliable film that is new. I still really like the film stock and will use it as a 200 iso film.