I just received the Sigma 50mm 1.4 HSM today, and I just wanted to post some pictures and full frame crops from the two lenses. As you can see, the sigma is much larger than the nikon. NIKON D3    ---    70mm    f/11.0    1/1s    ISO 200 On to the pictures (all f/1.4 taken with D3) Full Picture (Sigma) NIKON D3    ---    50mm    f/1.4    1/30s    ISO 200 Full Picture (Nikon) NIKON D3    ---    50mm    f/1.4    1/30s    ISO 200 Center Crop (Sigma top, Nikon bottom) Remote Crop (Sigma top, Nikon bottom) Lamp Crop (Sigma top, Nikon bottom) Food Package Crop (Sigma top, Nikon bottom) Conclusions: I'm not too happy about the Sigma in terms of center sharpness at 1.4. There seems to be some kind of strange offset in color, that goes away when stopped down a bit and strange optical abrasions. Center crop Sigma at 1.4 and 2.8 View attachment 245745 In terms of Bokeh though, I am very pleased. I was never happy with the bokeh of the nikon 50, and I feel I like the bokeh of the Sigma much better. Anyways, I just wanted to let everyone know how this lens performs, initially. I'll have some time to really use it in the field later, so I'll update everyone as I go.