It's not listed in the Rolleiflex 2.8F manual. I don't know if this helps, but I have a Rolleiflex 3.5E with a meter that would have been one of the last models before the F. It's max ISO/ASA is 800. If I were to guess I'd say that the F model probably goes up to 800 or 1600. I don't even use the in-camera meter as I prefer to use a hand held meter.