Nice work, first time I've seen a photo of one of these from this angle...
I've never managed a decent image of these, although I did actually see one landed on a wall once, by the time I'd returned with the camera he was flying around again and never settled..
That's a good catch! I see a few buzzing around my yard this time of year, but have never caught one photographically. Untill you know what they are, they do look rather fearsome.