A 400mm RF lens would be the same size as a 400mm EF lens with EF-to-RF adapter. The dimensions of a super telephoto lens is dictated by aperture (diameter of the front element) and focal length (roughly the length of the lens). There is room for minor amount of weight reduction by eliminating the mount adaptor, but it's probably not worth for Canon to make native RF mount telephoto lenses for a long time.This weight reduction is just fantastic. I had the 400 2.8 IS (original version for rent, it was not handholdable, and the IS quite bad. In Comparision, just recently I could use a 400 2.8 IS ii, which is a fantastic improvement.
Now, 1 kg less (as the 300 2.8 IS) and 1.5 stops better IS, there is nothing to add, except that I don't have 12k$ of pocket money to be burned. And the big concern, what about RF (beside the possibility of using adapters) ???
Now, comparing the weight differences between 300/400 or 600/500 lenses at the same opening, a 500mm 2.8 or a 700 4.0 at below 5kg comes into sight. for a bargain of 20k bucks maybe
Yes, slight improvement at the edges/corners (everything is at 600mm, since these are prime lenses). The MTF for the 400 MkIII should be on Canon Japan’s website (that’s where I got the MTF for the 600 III), although they don’t generally publish MTFs for lenses with TCs (with the exception of the 200-400 with it’s built-in TC).So seems like the difference in sharpness will be towards the edges and at 600mm? (am I reading it right).
AF at f/11 matters only for an f/5.6 lens with a 2x TC, so not really relevant for these f/4 lenses. A 100-400 with a 2x would AF on the EOS R (but that combo also can AF in live view on current DSLRs).I like what i'm seeing and hopefully they will have a new extender pair that comes with these lens. Since the EOS R can now autofocus at f/11 that's huge for those who use TC's.
Thanks. I did wonder when I saw those switches. I've only used focus by wire on the 85L II and I've no doubt the implementation will be better here, but I dislike it, and it would put me off upgrading even if I could afford to.
Starting from 3:00. There is even an additional switch to control the sensitivity or as they say “speed” of manual focus.
Thanks! And ugh. I saw the line in the feature list, “Improved, flexible focus control with a customizable electronic-focus ring,” but was hoping that referred to the focus preset ring which also drives Power Focus on the MkII lenses.Starting from 3:00. There is even an additional switch to control the sensitivity or as they say “speed” of manual focus.
Agreed. I had no plans to upgrade anyway, but this makes that even less likely. I manually focus my 600 II quite frequently, and I’m not a fan of FBW (having owned the 85/1.2L II and many EF-M lenses which are al FBW).Thanks. I did wonder when I saw those switches. I've only used focus by wire on the 85L II and I've no doubt the implementation will be better here, but I dislike it, and it would put me off upgrading even if I could afford to.
Note sure where you got the MTF plot for the mk II, but this is the plot I downloaded from Canon moments ago. The Mk II appears to be significantly better than the Mk III. And the same goes for the 400 Mk III.600/4L IS II:
600/4L IS III:
I’m not sure I’d call the MkIII worse, but based on MTF charts I’d conclude that the MkIII does not offer any meaningful improvement in sharpness or contrast. The new coatings are likely better at reducing flare (and of course, that affects contrast when present), but I haven’t found that to be an issue with the 600 II (unlike, for example, the 70-200/2.8L IS II, where despite the claims of no improvements, I expect that lens to have meaningfully better performance in backlit situations, where the MkII just washes out with veiling glare).