Not the sharpest photo I've ever taken, but I decided to haul out a lens I haven't used in a long time: a Sigma 400mm f/5.6 APO. I shot this photo of a coot on the Housatonic River in Connecticut using that lens with a 1.4x tele-converter (also Sigma). Coots are a real challenge to shoot because they just never stop moving, they are like perpetual motion machines when they're in the water--and they are small and fast. I was close enough to the riverbank that I found shooting from my van with the lens resting on a rolled up sweater in the window frame was the simplest solution. I shoot on a tripod about 95% of the time, but sometimes you have to improvise and being up high in my van gave me a good vantage point. I had to sharpen this quite a bit in Photoshop and it's still not blazingly sharp. I think the slight softness is due to the motion of the bird and the extreme focal length (with the 1.4x) more than the quality of the glass: on a dx Nikon body the 400mm is 600mm effectively and with the added 1.4x tele-converter, it's a whopping 840mm. It's a been a great winter/early spring for birding in Connecticut.