I own the Sigma 14mm f/1.8 for astro. It's great! but it's a DSLR lens, and Sigma makes it for the Nikon F mount, which means they had to design their optics around a very small opening with a big flange distance. That's a big deal for fast, super-wide lenses, which benefit the most from the wide openings and short flange distances of modern mirrorless mounts. Canon could certainly make a 14mm lens one stop faster for their R mount. No doubt it would be huge, but so is the Sigma, and it's always on a tripod, anyway. BTW, the vignetting isn't ever a real-world problem for me... We've been testing the Canon 24-240 RF which has serious vignetting and distortion at 24mm, but the camera and Lightroom both automatically correct for it in post, which means you never see any problem with your images. I am fine with that.
Hi Tony,
First off, thank you for running your YouTube channel.
Let me provide some Perspective on 14/1.8 vs 14/1.2 subject.
As we are well aware, an elevated vignetting levels on RF mount are associated with a shorter mount flange distance. A longer lenses are less affected as there is no requirement for light to be bent at extreme angles. As we all aware. Ticked.
with shorter focal lengths, bending light to reach extreme corners and micro lens position is becoming an issue.
Yes, 2-3 stops of vignetting is an unfortunate reality however is manageable.
However, at 14mm and F1.2 vignetting levels may reach some unmanageable levels. 6 stops or even more
Bulbous front 105mm front element is given. at least. It’s a 2kg lens.
Another issue I guarantee to be a problem for Astro in some serious level or commatic aberrations in corners and ugly shaped stars in result.
theoretically, such a lens can exist. commercially it would have to be an expensive, specialty lens.