This is a single 5-minute exposure taken on 16th December 2004 at a reasonably dark location at the Ghubra Bowl in Oman, elevation around 680mm. Conditions were dark enough that you could unambiguously locate M31 with the naked eye. While the sky was not very dark all over (some scattered wispy clouds and a bit of haze in various directions) it did look pretty dark in the direction of M31, eg spiral arms were easily visible in M33 through a 20" Obsession.