Hello, as I noticed some kind of new to me "halo" around high contrast edges on my Sigma at 400mm wide open, I eventually did a test series using my D200. Set up on a tripod, using MLU and remote shutter and out came the below series, each a 100% crop. I think you can clearly see that kind of halo I mean on the leaf's edge. I'm curious to see such a series for the Nikkor (or maybe the Sigma 120-300 ) or other lenses around 400mm to get a feeling how normal that IQ is. Downscaled to web size it looks quite well, so from looking at the usual posted image size, you can hardly get a clue how IQ is actually for that particular lens, wide open. Anyone? As you can see on the other leaf edges, that effect is mainly (only?) visible on edges of high contrast, i.e. some bright objects.