I am looking for first developer times for Kodak E-6 chemistry for Fuji 64T RTP II
Kodak recommends 6 mins for the first developer but I have using 6mins 30secs for Velvia with consistent results.
Should I continue to use 6mins 30secs as this is quite a slow film?
A 1996 Kodak Color Darkroom Dataguide specifies 6:00 as the first-developer time. My most recent Kodak E-6 kit specifies a first-developer time of "6 to 7 minutes." The box doesn't contain any further elaboration of that, as far as I can see. Moving away from Kodak recommendations, I've seen claims from some people that Fuji films benefit from somewhat longer first-developer times, at least in Kodak's E-6 (vs. Fuji's or third-party equivalents).
I always shoot Velvia 50 with the camera set to ISO40 to get satisfactory results; I guess as an alternative you could extend the first dev - I.e. Either is an admission that Velvia 50 is slower in reality than the ISO rating would have you believe. Velvia 50 is the only film I make any adjustment for though, for what it's worth (not much, I know!)