Thanks to Tony Northrup I went there and after a lot of playing around trying out different lens and camera comparisons it was obvious that anything less than full-frame (in 35mm terms) was not worth considering – at least this is what the numbers were reporting. If you cared about sharpness and resolution forget APS-C and certainly forget about MFT!
It didn’t help in that there was something wrong with the site in that it stopped refreshing when you tried different comparisons – it was a more painful exercise than it should have been.
The other problem is that D750 and the A7 are not on the site; I can understand why the D750 isn’t but the A7 was released over a year ago and the Sony A7R is on the site. So I had to use the A7R as the ONLY full-frame Sony camera. For Nikon I used the D610 which is a much fairer comparison as this camera’s sensor will be very close to the sensor in the D750.
The more I played with the site the more I came to the conclusion that I was wasting my time as I couldn’t do fair comparisons between different cameras and when looking at third party lenses (such as the Sigma 24-105 f4 OS Art lens) I had to compare the Canon mount version against a Nikon camera with a Nikon equivalent (in this case the 24-120 f4 VRII lens).
The other problem highlighted by this site is that few lenses are getting even close to matching the possible resolution from the camera that they are attached to; the lenses that do are obscenely expensive. The big surprise for me is that the newer third party lenses from Tamron and Sigma are outperforming the equivalent Nikon lenses although they seem to vignette more and are all guilty of focus breathing too which could be an issue at close distances.
That all said the Nikon lenses are still very good, if they weren’t I think we would have heard more about this by now. I don’t see a lot of professional shooters picking the latest f2.8 Tamron zoom lenses over the Nikon equivalents even though they are cheaper.
Don’t be tempted to go to the DXO website – just don’t, you’ll be disappointed. This is unless of course you have the D800e/D810 with the multi-thousand dollar lenses that match the resolution of the camera sensor!