I use TMY at 1600 and it pushes well. I get nice tones by processing it in Xtol 1:3. I would recommend dilute development for your TMX. Kodak suggests Xtol 1:1, 12-1/4min at 68F/20C (9min at 75F/24C). They even have times for using TMX at 800, so you should be OK.(posted 8732 days ago)