Canon Patents

Patent: RF mount super telephoto lenses

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.

Canon RF 400mm f/2.8L IS USM

  • 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

Canon RF 600mm f/4L IS USM

  • Focal length: 588mm
  • F number: 4.12
  • Angle of view: 2.11°
  • Image height: 21.64mm
  • Entire lens length: 476mm
  • Backfocus: 33mm

degos

EOS RP
Mar 20, 2015
200
122
Blah blah blah Canon. Where are the long DO lenses?

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.
 
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SV

EOS M50
Aug 24, 2017
27
19
No mention of a 300 f/2.8 RF?
Or anything RF DO?!?!?
 
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Jack Douglas

CR for the Humour
Apr 10, 2013
6,097
1,033
Alberta, Canada
That answers one question but for me weight is still more important. It seems they are concerned with some aspect of the performance or are challenged by some aspect of the production of DO versions or they would be first and foremost coming out??

Jack
 
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Mistral75

EOS T7i
Oct 13, 2013
93
24
(...)

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.
The RF versions would actually be shorter than their EF counterparts. In a patent request 'entire lens length' means from the front-end of the first element to the sensor: a patent is not linked to a specific mount / flange focal distance.

You should therefore add 44mm to the length of the EF lenses to make your comparisons.
 

AlanF

Canon 5DSR II
Aug 16, 2012
5,658
2,912
That answers one question but for me weight is still more important. It seems they are concerned with some aspect of the performance or are challenged by some aspect of the production of DO versions or they would be first and foremost coming out??

Jack
The Nikon 500mm f/5.6 PF weighing in less than a 100-400mm II at 3.2lb (1.46kg) is selling like hot cakes and is back-ordered everywhere. Our 400mm DO II with lens hood weigh 2.265kg, and with a 1.4xTC 2.51kg or 5.5lb. If they were freely available, I would get a 500mm as I feel that extra kg over my shoulder. At least I have the good old 100-400mm II, which is unmatched.
 

neuroanatomist

I post too Much on Here!!
Jul 21, 2010
24,607
2,060
The RF versions would actually be shorter than their EF counterparts. In a patent request 'entire lens length' means from the front-end of the first element to the sensor: a patent is not linked to a specific mount / flange focal distance.

You should therefore add 44mm to the length of the EF lenses to make your comparisons.
To compare lens lengths, one should instead subtract 20mm from the RF patent length. Doing so based on the above measurements indicates the lenses are essentially the same length.

Still not seeing the purported ‘benefits of the RF mount’.
 

Graphic.Artifacts

EOS 7D MK II
Aug 1, 2017
426
244
To compare lens lengths, one should instead subtract 20mm from the RF patent length. Doing so based on the above measurements indicates the lenses are essentially the same length.

Still not seeing the purported ‘benefits of the RF mount’.
i guess this is going to sound snarky and I'm saying this generally rather than to a specific poster. "Did anybody really expect to?"

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.
 

3kramd5

EOS 5D MK IV
Mar 2, 2012
3,082
404
i guess this is going to sound snarky and I'm saying this generally rather than to a specific poster. "Did anybody really expect to?"
Yes. There are a number of members on this website who have for years proselytized mirrorless cameras as capable of diminutive lens sizes.
 

Jack Douglas

CR for the Humour
Apr 10, 2013
6,097
1,033
Alberta, Canada
Not sure about the comment regarding the EF lenses becoming useless - the 70-200 II worked beautifully on my daughters R and she had the added benefit of the ISO setting via the ring adapter. That's true manual exposure shooting with really easy right finger adjustment of ISO based on the viewfinder image. I think EF lenses will just slowly disappear without much fanfare.

Jack
 

padam

EOS 7D MK II
Aug 26, 2015
582
209
Not sure about the comment regarding the EF lenses becoming useless - the 70-200 II worked beautifully on my daughters R and she had the added benefit of the ISO setting via the ring adapter. That's true manual exposure shooting with really easy right finger adjustment of ISO based on the viewfinder image. I think EF lenses will just slowly disappear without much fanfare.

Jack
It will take a very long time to disappear (Canon are still selling lenses that are very very old now), but if IBIS will be working to its full potential with EF lenses as well, they will actually become a bit more desirable than before (also for video with the built-in ND adapter and physical manual focus, which is only for EF and not RF)

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).
 

padam

EOS 7D MK II
Aug 26, 2015
582
209
Blah blah blah Canon. Where are the long DO lenses?
Maybe something has changed regarding production costs, because the EF 600mm f/4 DO BR IS looked close to serial production. Maybe they will get back to it once they figure it out, looks like Nikon also has trouble with their 500mm f/5.6 PF ED VR.

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.
 

Kit.

EOS 6D MK II
Apr 25, 2011
1,264
681
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.
As long as these lenses work on Sony cameras, it would be extremely stupid for Canon to do something like that.
 
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unfocused

EOS 5D SR
Jul 20, 2010
4,938
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www.mgordoncommunications.com
Yes. There are a number of members on this website who have for years proselytized mirrorless cameras as capable of diminutive lens sizes.
True, but to be fair, one of the most vocal (and overbearing) proselytizers envisioned modest primes and variable aperture zooms. Many of these lenses (the 24mm f2.8 for example) are already small, so a slight decrease in size would make a difference. Canon seems to be going in another direction right now, leaving small size to the M series and focusing on either duplicating existing EF lenses or creating new high end lenses for the R. Only Canon knows why they are heading in that direction. I would speculate that they are sending a message to the industry about their willingness to expend considerable resources to aggressively compete in the mirrorless market.
 

canonnews

EOS RP
Dec 27, 2017
315
266
Canada
www.canonnews.com
To compare lens lengths, one should instead subtract 20mm from the RF patent length. Doing so based on the above measurements indicates the lenses are essentially the same length.

Still not seeing the purported ‘benefits of the RF mount’.
shouldn't see any advantage really except perhaps a better balance on an RF super telelphoto.

as we originally discovered with this patent last thursday, about the only change is a shifting of the elements closer to the back.
 

neuroanatomist

I post too Much on Here!!
Jul 21, 2010
24,607
2,060
shouldn't see any advantage really except perhaps a better balance on an RF super telelphoto.

as we originally discovered with this patent last thursday, about the only change is a shifting of the elements closer to the back.
True, but not RF-specific. That same sort of shift was done in the EF 600/4 III – moving the lens groups behind the front element closer to the mount, which allows them to be smaller in diameter (= lighter), and shifts the center of mass toward the body (= better balance).
 

Graphic.Artifacts

EOS 7D MK II
Aug 1, 2017
426
244
As long as these lenses work on Sony cameras, it would be extremely stupid for Canon to do something like that.
You may be right. This sort of thing has to be done at a fairly slow pace. You don't want to have any abrupt changes that can organize resistance.

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.
 
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canonnews

EOS RP
Dec 27, 2017
315
266
Canada
www.canonnews.com
True, but not RF-specific. That same sort of shift was done in the EF 600/4 III – moving the lens groups behind the front element closer to the mount, which allows them to be smaller in diameter (= lighter), and shifts the center of mass toward the body (= better balance).
similar, yes, but not as much. This shift was RF specific. the shift was around 40-50mm more than what you see on EF super telephotos, which is why we identified these as RF super telephoto patent applications.
 

jolyonralph

Kodak Brownie
Aug 25, 2015
1,094
310
50
London, UK
www.everyothershot.com
These lenses are aimed at the professional market, not the well-heeled amateur. If the professional wants the lens and the RF version gives faster and better focus, it doesn't matter about how it compares to the EF version in length, or even weight (although it's not likely to be MORE). If the professional doesn't have an R body and needs this lens, they'll get an R body.
 

neuroanatomist

I post too Much on Here!!
Jul 21, 2010
24,607
2,060
similar, yes, but not as much. This shift was RF specific. the shift was around 40-50mm more than what you see on EF super telephotos, which is why we identified these as RF super telephoto patent applications.
It seems obvious they are RF patents based on the 31-33 mm back focus distances specified in the patents.

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.

184781
 
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