I'm just about to buy this lens. I know it's stellar optically. But how does it perform with Canon 90D PDAF? Are all focus points usable and is it spot on?
I don't have that specific combo, but I do have a canon 80d (prior to going to R5) and sigma lenses worked great with them (150-600, 20mm 1.4 Art, 35mm 1.4 Art and 10-20mm 3.5 ). 3rd party is generally a bit slower but focus seemed to be on par with native EF and EF-S lenses.
They also work just fine on the R5 with EF-RF adapter.
Thanks on your report. Was thinking about it more in the mean time, and I think I will go for Canon 35mm f2 IS, since I'd be using Sigma at 35mm the most anyway.
With Canon 35mm f2 IS I get - full Canon AF compatibility, both on Crop and FF and great IS.
On Sigma I'd get more range, 1/3 brighter lens and slightly sharper images. But much heavier, more expensive, no IS, no FF compatibility, with a hope that AF will be always accurate.