It looks like Sigma is continuing to work on wide angle lenses for full frame cameras. A recent patent application shows an optical formula for a 12mm f/2.8 Art series lens for full frame cameras. Sigma 12mm f/2.8 Art Specifications:
- Focal length: 12.42mm
- F number: 2.93
- Angle of view: 120.49
- Image height: 21.63mm
- Lens length: 169.4mm
... quadruple use lens: compatible with small filters via RF filter adapter !
The RF mount, with its 20mm flange focal distance, versus 44mm for the EF mount, enables optical designs which are of equal or better optical quality while using less super-expensive optical glass. Less glass means that the lenses are not only smaller and easier to use, but also means that the lenses can allow customers to save money and/or Canon to make a bit more profit and thereby invest that added profit in developing new technology faster and better for all of us to benefit.
The RF mount is the future, a very, very bright and promising future. I am especially happy Canon chose to go with 20mm to maximize the strength of the mount while still achieving an optically-optimized mount solution compared to which the previous EF mount was at a 220% disadvantage (44/20).
This is a huge deal, as attested to in spades by the incredible optical quality of new RF lenses like the f/1.2 50mm and f/2 zoom. Those lenses would have been unmanageably huge and nightmares of optical complexity just to achieve equivalent image quality when engineered with a 44mm flange focal distance in mind.
The Laowa Zero-D 12mm f/2.8 would be a direct competitor, and the EF 11-24mm f/4L and Sigma 12-24mm F4 DG HSM Art as alternatives as well.
I use the Laowa as a real estate Workhorse. It is a great lens and I don't see how the sigma could improve unless it has auto focus.. I use this lens on my EOS are with the adapter and it is flawless I love the focus peaking
Auto focus isn't all that useful on such a wide lens.