thanks all ! so well, they starting flying against the big blue sky and I kept snapping - ah, the easy explanation, and i tried it for sure, and couldn't get anything in focus, more difficult than a bif ! so, really , how this was taken was - on a light table - a dandy and its wings spread out and a shot taken from above. in PS, since the edges were not well-defined, I did a finding edges, and some increased contrast and stuff for the final image. I had seen a similar and better version somewhere which was the inspiration !