[wiltw]

I was able to print an 8x10 using a #3 filter at 3 seconds exposure, around f/5.6 I think, and produce something that I like.

Last night I was thinking about trying a 16x20 of the same print.... I want to try and have an idea of how the distance may change my exposure time, before I start wasting 16x20 sheets...

Kodak enlarging dial in the Kodak B+W Dataguide says: 8X 3sec f/5.6 becomes 16X 10.5sec f/5.6