100 - 400 sigma lens
HI yes I have had the lens for a while now however as there was going to be a long delay for the Sigma mount version I got one for my Nikon instead. It is a brialliant lens and very sharp, if you read reviews at B & H you'll see most if not all people think highly of it. However I have noticed that sometimes, and I cant say for sure what mode it was in 1 or 2 I see a bit of 'wobbly' edges. Perhaps it has caught the switch as I have pulled the lens from the bag and changed but it is quite weird really. Not seen often and I have not spent enough time checking it out to say if it was very slow shutter speeds or what. It was not a pixel staircase effect it was like a rippling effect. As mentioned only very very rarely have I seen it.
The lens is brilliant only it is heavy too, I have a bad neck and fid it difficult to carry too far, in some what when . It is fine for birding, though I have not done much at all, it has caught a couple of in flight pictures that are good and sharp, whiole I panned the camera to keep up.
Hope that helps and good luck
Mike