On my last trip, I used Velvia 100 for the dimly lit scenes because of its excellent reciprocity failure characteristics. For those who are not familiar with reciprocity failure, many films will require you to add extra time to a long exposure. In some cases, you have to use twice the metered exposure. This can be a major issue when a 4 minute exposure becomes an 8 minute exposure.
Velvia 50 is commonly used for landscape photography, but it will suffer from color shifts with long exposures, and is not recommended to use much beyond a one second metered exposure.
I was very satisfied with how the velvia 100 reacted to the lighting conditions on my last trip. Unfortunately, it is back ordered into January for the 8×10 size. Instead, I have purchased some Provia 100, which is a less saturated film. If necessary, I can always add a bit more saturation prior to print.
My plan is to shoot the same scenes with both Velvia 50 (which may have questionable performace) as well as Provia 100 (my safety net). Between these two films, I think I should be in good shape.
Nearly everything is ready for the trip to Zion this coming week. I’m looking forward to it!