My album of shots from last night w/ the Tokina 300mm lens and Sony A7S:
https://plus.google.com/photos/11626...23080982393841
A few overlaps with the Flame and Horsehead nebulas and other scattered targets, in particular the Pleiades star cluster.
The lens is definitely NOT as good as the Astro-Tech 65EDQ and has serious vignetting on a full frame sensor (but then again it is a crop sensor lens). In crop mode the lens has almost exactly the same field-of-view as the AT65EDQ (when used on a full frame sensor).
Enjoy!
bwa