What lens/camera/filter combo are you using there Bob, plenty of vignetting going on?...Nice pics regardless mind.
I agree - damn birds were too close! I was digiscoping - using a coolpix 995 with a dca adaptter on a swarovski ats80hd. So there's digital zoom in the camera, and 20x on the scope, yet the birds were only 50m - 150m from me. So the camera zoom was as low as 1.6x - especially for the Little Ringed Plover pic, the bird was very close, hence the vignetting - it only really fully disappears at 2.8x +. But the pics are as taken, not tweaked at all, hence you noticing it! I can't be arsed with editing them, I only take them as record shots really. It's not every day you see a spotted redshank on your doorstep; little ringed plovers too are noticeable, although one or two pairs do breed locally.
Any advice appreciated, though! I've only taken all this up this year, just used good old binoculars before! Also timiano, I notice that you say that you post your pics elsewhere - did you mean on RAWK or another site? I'm interested in bird photo sites ...