ballpark exposure time needed

[sven]

hi everyone, I've been wanting for a very long time to do night time moonlit exposures, tonight all is absolutley perfect, with the added bonus of a very heavy covering of snow over the rolling hills outside my back door. Here there is absolutley no light pollution whatsoever, the full moon is very bright and i'm vaguley aware of reciprocity, although as a total greenhorn,I wonder if anyone out there could suggest an approximate exposure duration, i'm using fp4 and an aperture of f 45, (a 5x4 graflex) which is the smallest ive got, perhaps i could use a larger aperture? , I only have two sheets of film to play with, i was going to do the first at 18 mins then the second at 36 mins, thanks to everyone and happy new year cheers sven

[Joanna Carter]

It may be too late by now but I found this page