Quote Originally Posted by Tony-S View Post
Are you sure about that? Velvia 50 used to start suffering from the reciprocity effect after 1 to 4 seconds, plus it required magenta filtration. This is one of the reasons I use Provia 100F - it has much better reciprocity characteristics. Has Velvia 50's forumulation changed in the last few years? Here's a shot with Velvia 50 that exemplifies its weak reciprocity characteristics.
The Fuji Velvia 50 datasheet (AF3-0221E2) does list a range of durations but it does state not recommended over 64 seconds.

So I conducted about a 7 hour start trails test - my first ever, using Velvia 50 and got the image below with no compensation or filtering. I learned that I should know if the moon will appear in the scene sometime during the exposure. I think the yellow pine trees - normally green, was due to light from around my backyard.

Anyway, plenty more trial and error to have fun with. I like the that there are uncharted territories to explore . . .