It looks like Canon is indeed working on their RF mount super telephoto optical formulas. We were told a couple of days ago that an RF 500mm f/4L IS would be the first super telephoto lens launched for the EOS R system.
A USPTO patent has appeared that shows optical designs for an RF 400mm f/2.8L IS, RF 500mm f/4L IS and an RF 600mm f/4L IS.
- Focal length: 392mm
- F number: 2.9
- Angle of view: 3.16°
- Image height: 21.64mm
- Entire lens length: 360mm
- Backfocus: 31mm
Canon RF 500mm f/4L IS USM
- Focal length: 490mm
- F number: 4.12
- Angle of view: 2.53°
- Image height: 21.64mm
- Entire lens length: 412mm
- Backfocus: 33mm
- Focal length: 588mm
- F number: 4.12
- Angle of view: 2.11°
- Image height: 21.64mm
- Entire lens length: 476mm
- Backfocus: 33mm
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Also interesting that the RF 600mm f4 is longer than the EF versions, 476mm versus 448 ( III ) and 457 ( II ). Which might not seem a lot but does complicate finding an appropriate carry-on-friendly backpack, for example.
Actually on further research they're all longer than the EF variants.
Or anything RF DO?!?!?
Jack
You should therefore add 44mm to the length of the EF lenses to make your comparisons.
Still not seeing the purported ‘benefits of the RF mount’.
The true benefit of the new mount is that Canon, one way or another, is going to find a way to get RF mount users to buy "improved" versions of all their existing EF lenses. Regardless of whether they're any better. So much for EF lens compatibility. If EF lenses are going to be seamlessly compatible why the dramatic push for new lenses.
It's only a matter of time until we start hearing about "issues" with legacy EF lenses on the newer R's. Sure they'll be lots of faux surprise/outrage when that happens but it's coming. Canon will tear that page right out of Apple's book when the time is right.
I'm very surprised by how casual this forum is regarding the EF mount's impending and unnecessary obsolescence for no reason other than a shorter flange distance and some "special sauce" in the new interface.
If you had posted in this forum a couple of years ago that "Canon was going to junk the EF mount" hundreds of posters would have been standing in line to call you an idiot. Now everyone seems to think it's a great idea. Go figure.
Yes. There are a number of members on this website who have for years proselytized mirrorless cameras as capable of diminutive lens sizes.
Jack
Of course, ergonomically, the RF lenses have a bit better weight distribution but they will probably remain as an integral part of the system (unlike Nikon or Sony where compatibility is much more limited to newer lenses).
If they can keep decreasing the weight even further than their recent version III EF supertelephotos, that would be quite impressive on its own. It is probably about 2-3 years away anyway.
as we originally discovered with this patent last thursday, about the only change is a shifting of the elements closer to the back.
I'd imagine it will probably start with "special features" that only work on a combo of R/RF bodies and lenses. Once users have become desensitized to the idea that RF lenses perform better than EF lenses on R bodies you can move to the next phase. The "stop complaining and just buy new lenses" narrative. It's a continuum. You can't move along it too quickly or it won't work.
I've worked around tech long enough to know how this movie ends. I've seen it often enough. You can't really blame Canon. It's the smart play from a marketing perspective. But it's going to crush the resale value of my EF lenses so I can't say I approve.
Based on an appropriately-scaled overlay, the second group back from the front element (G1n) sits ~6mm behind the corresponding group in the 600/4 III, and the next group back is ~12mm behind the corresponding EF group.