QUOTE (David Marshall @ Mar 12 2006, 12:00 AM)

Hi... Still using Velvia 50 as long as it remains available, and rating it at ISO 40 as recommended by most pros. But the time will come when I have to try Velvia 100, so the question is what should it be rated as to get best results - ISO 100 or perhaps 80?

Without question my favorite film is fuji velvia 50. I also shot it at 40. I have used the velvia 100 with no changes in ISO settings and seems to work just fine. Like all films it really depends on what your trying to accomplish. I shot with a pentax 6x7 med. format and work a lot with moving water such as streams and waterfalls. I really prefer the velvia 50 for this type of work. When it comes to landscapes I find the 100 just fine. The tuff part is getting away from the films you love to use. Give it a try. I don't think you'll be disappointed. Have fun. Nelson
Not sure..never used 100 Velvia. However, I have never set ISO of asa50 at 40. A lot of folks have.
Chuck Freeman USA