I couldn't find any file info in the EXIF so will only have to take your word for it . Even with a 50mm f/1.8 it's unbelievable with those settings .
Nope, that's about right with those settings. I usually shoot the Milky Way at f/2.8 with my Tokina 11-16, and his settings correspond fairly well to what I get, once they're scaled for focal length and exposure settings.

on the right hand side. 




