Canon RF 10-20/4 test chart on TDP

TDP did release the test chart shots of the new RF 10-20/4.

And results look very good to me. In a direct comparison with the EF11-24/4 it seems to be similarly sharp at the wider half of its zoom range (but without the fringing of 11-24). At the longer half of its zoom range the new lens has a bit sharper corners, at 20mm notably sharper. Wide opened sharpness considered, but the rest of the aperture range somehow copies that.

Vignetting is somehow within expected margins for the RF lens. Wider half of the zoom range is approx similar to the predecessor, at longer half of the zoom range the new lens is about 1 EV worse at sides/corners.

Price of the new 10-20/4 is very friendly compared to the previous 11-24/4 and considering it might be overally a bit better performing lens. So for people looking for the max UWA reach in a light compact package, this lens might be a good deal. Although the overall value is rather mediocre in my subjective eyes, considering we are getting an f/4 only plastic lens for 2300 USD. But sure, the value here is in the 10mm FL, no doubt about that.

Looking at a website via my laptop screen is certainly not definitive, but to my eye the new lens appear slightly softer when stopped down in comparison to the 11-24mm even if its a bit better at F4.

My 11-24mm reacted well to stopping down prior to the diffraction limit kicking in and in my use cases I would typically be optimizing around F8. I am curious how the new lens performs in these scenarios when mine arrives, as shooting a 10mm wide open seems unlikely for me.