Found this all grey/silver fly wandering around yesterday about 12 to 15mm body length and did not want to fly or stay still either. Assume it's recently hatched but hasn't properly dried it's wings off or coloured up properly yet.
I thought it might be a Sarcophagid fly but have a possible ID as a Tachinid Exoristinae - Goniini - Gonia sp. from Jorge on Flickr/diptera info.
Taken at 1:1 I think, focus stack from 2 shots