Sigma 56 F1.4 on M6II versus RF 85 F2 on R

thunder storm wrote:

I compared the Sigma + Lightroom in the corner to the RF + Lightroom in the corner.

Conclusion: it's hard to compare with fields of view not being the same and - as I assume - the camera at the same distance. The contrast of the RF 85mm is better.

Well, to be fair, the fields of view are pretty darn close. The magnification of the 56, giving a 90 FF equivalent FOV, is only slightly more than the 85. The framing of one shot starts ever so slightly more to the left than the other. The subjects in each case are pretty close in size. From the top of his head to the bottom of his feet, Paddington is 1320 pixels on the Sigma shot and 1260 pixels on the Canon RF shot.

The difference in processing show it's possible Canon's in camera jpg engine is doing tricks with budget RF lenses to make those appear to be sharper like the DXO PL5 does, giving better contrast at the cost of bokeh quality. At the same time the RF lens has better contrast with the same processing in Lightroom, so comparing to the sigma there's an optical difference too for contrast.

You might be correct, though all that matters for me is the end result, not how we get there. But still, the differences are so small that you'd have to be an obsessive pixel peeper (like most people here are!) to base a choice of system on them, rather than differences in usability, feel, portability, etc, which are far more important to a lot of people (me, for instance).