RF 14-35 and cropping

Stein Rune Risa wrote:

@Sittatunga - Thanks for your comprehensive answer!

From your post, I understand that:

Yes - I can expect the images from the 14-35 to be 14 mm after correction, and that any dark corners etc are actually in "a wider part" than the 14 mm view. And that other software than DPP might actually be able to provide even wider - but maybe not with this lens.

Correctly understood?

Yes, though the corners are also brightened by the vignetting correction. And I have noticed with a variety of lenses that correcting barrel distortion with PhotoLab gives me the option of getting a bit more of a wide angle by cropping to a longer shape, because of what that correction does to the shape of the included rectangle. My 16-35mm is newer than my EOS R, so it's going to be a long time before I buy a wide-angle zoom in that class, but I would fully expect PhotoLab to extract a wider angle from the RF 14-35mm than DPP4 when the uncorrected image shows barrel distortion. The catch, of course, is the quality at the extreme corners.

It's early days but my zoom is cleaner in the corners than my 16mm, yet field curvature can sometimes make the bottom corners of the prime look sharper than those of the zoom. I need to investigate this more thoroughly.

I see in Dustin Abbott's review of the lens here:

https://dustinabbott.net/2021/10/canon-rf-14-35mm-f4l-is-usm-review/

that he shows some of this vignetting and distortion. I can see that his manual correction effort actually is wider than the in camera ones. But he also writes "I would say the corrected image from the Canon probably behaves more like a 15mm lens."...