March 23, 2023

Canon R5 - notes on lenses

One of the big reasons I went with a Canon R5 instead of one of the Sony A7 full frame mirrorless cameras is that I have a substantial investment in high quality Canon lenses. There are other reasons as well, but this is a big consideration.

This means that with the R to EF adapter (which seems to work perfectly), I have no compelling reason to buy any R lenses! Maybe ... read the following white paper:

I hear the statement that the large diameter "hole" for the mount makes a big difference -- but the hole is the same size as the EF lenses. It seems clear to me that the game here is comparing to the Sony E mount. The Sony E mount has a 46.1 mm hole and the Canon RF mount has a 54 mm hole. For the record, note that the Nikon Z mount wins the prize with a 55 mm hole and a 16mm flange distance.

As a summary, the R lens mount, by having a big diameter and a short flange distance, opens up new possibilities for lens design (i.e. removes some old limitations). Whether and how well this will be exploited depends on each specific lens design.

Interesting R lenses

I have said that I have no urge to buy R lenses, but that isn't quite true. As I write this, the RF 24-105MM STM lens is on order (because I want a compact and light lens for travel and casual use). Also comments in the Canon white paper above suggest that the R system allows improvements in lens design -- so that an R lens may be a better performer than its EF equivalent due to advantages of the R system, along with general improvments in the state of the art in lens design. There are some that interest me though:

Note that in the following, "STM" denotes a lens with the focus mechanism driven by a stepper motor. This means that the lens will "sing" a bit while focusing. To avoid this, you have to spend significantly more money and get a USM lens (USM = ultrasonic motor). I have EF mount USM lenses.

Canon RF 24-105mm f/4-7.1 IS STM lens. This would be a light and compact lens that gets decent reviews. You can pick it up for under $200 (full price is $400). It has image stabilization! So if I planned on traveling, or just didn't want to haul around my big heavy 24-70 f/2.8 L lens, it would be a nice option. Note that there is also a 24-105 f/4 L lens that costs 3 times as much. The only negatives I see are that it does close down to f/7.1 at the long end, and it has no manual focus ring. The reason to buy this is because you want a light compact lens.

Canon RF 16mm f/2.8 STM -- a super tiny ultra wide lens. Full price is $279. This is recommended for video work, though certainly not limited to that. Full price is $279.

Feedback? Questions? Drop me a line!

Tom's Digital Photography Info / tom@mmto.org