Patent: Canon RF 17-35mm f/4-5.6

neuroanatomist

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Jul 21, 2010
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It does help to make better lenses. Just look at the RF 28-70 F2.0 or a new RF 85 F1.2. These are unique and/or amazing lenses.
Maybe. Canon has prior patents for f/2 zooms, Sigma makes one for EF (although of a much more limited zoom range). An 85/1.2 is certainly not unique to RF, nor are ‘amazing’ lenses. I’d have thought something like an 11-24/4 would be potentially unique to a shorter flange, but Canon went ahead and did it for EF.

Obviously it’s difficult to prove a negative, but it’s not obvious that any of the current RF lenses would be impossible for EF. Similarly, the current lenses as well as the patents we’ve seen do not support the claim that RF lenses can be smaller than EF counterpart (and for the 70-200, the RF version in the patent is actually larger than the current EF).
 

SecureGSM

2 x 5D IV
Feb 26, 2017
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Maybe the RF lenses are designed to minimize vignetting by controlling the incidence angle of light on the sensor.
Maybe. Canon has prior patents for f/2 zooms, Sigma makes one for EF (although of a much more limited zoom range). An 85/1.2 is certainly not unique to RF, nor are ‘amazing’ lenses. I’d have thought something like an 11-24/4 would be potentially unique to a shorter flange, but Canon went ahead and did it for EF.

Obviously it’s difficult to prove a negative, but it’s not obvious that any of the current RF lenses would be impossible for EF. Similarly, the current lenses as well as the patents we’ve seen do not support the claim that RF lenses can be smaller than EF counterpart (and for the 70-200, the RF version in the patent is actually larger than the current EF).
just a couple of comments:
Sigma 24-35 F2.0 is a very limited zoom range lens. 28-70/2.0 is impossible in EF variant.
Sigma’s CEO commented on number of occasions that Sigma 18-35/1.8 despite being only APS-C lens, was very difficult to design and manufacture. They nearly lost the case. Therefore 28-70/2.0 for FF camera is literary a unique lens.
On another note, Canon RF 85/1.2 is an amazing lens indeed. The MTF is so good it is rediculous :)
There are other signs that lens is better than just good.
 

Woody

EOS 6D MK II
Jul 20, 2010
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I will be very curious about the EOS-R system once the lightweight f/4 (or slower) zoom lenses are released.
 

neuroanatomist

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Maybe the RF lenses are designed to minimize vignetting by controlling the incidence angle of light on the sensor.
Then why do the current RF lenses have as much or more vignetting than their EF counterparts?
 

QuisUtDeus

EOS 80D
Feb 20, 2019
115
80
Maybe. Canon has prior patents for f/2 zooms, Sigma makes one for EF (although of a much more limited zoom range). An 85/1.2 is certainly not unique to RF, nor are ‘amazing’ lenses. I’d have thought something like an 11-24/4 would be potentially unique to a shorter flange, but Canon went ahead and did it for EF.

Obviously it’s difficult to prove a negative, but it’s not obvious that any of the current RF lenses would be impossible for EF. Similarly, the current lenses as well as the patents we’ve seen do not support the claim that RF lenses can be smaller than EF counterpart (and for the 70-200, the RF version in the patent is actually larger than the current EF).
Well... I'd argue that if you consider the system, the R+RF35 is smaller than the R+adapter+EF35/2IS. Not by a huge amount, but it's smaller, and they added semi-macro and a third of a stop in that moderately smaller space. Was that enabled by the RF mount? Like you say, it's hard to prove, but it's possible.
 

neuroanatomist

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just a couple of comments:
Sigma 24-35 F2.0 is a very limited zoom range lens. 28-70/2.0 is impossible in EF variant.
Sigma’s CEO commented on number of occasions that Sigma 18-35/1.8 despite being only APS-C lens, was very difficult to design and manufacture. They nearly lost the case. Therefore 28-70/2.0 for FF camera is literary a unique lens.
The lens itself is unique, but that doesn’t preclude the possibility of such a design for a longer flange. Sigma is also more constrained on their ability to price lenses, which certainly would have an impact on what they could design. As I said, maybe. Without the lens design experience, qualifications, and engineering/software tools of design teams across multiple manufacturers, how can you say for sure?

On another note, Canon RF 85/1.2 is an amazing lens indeed. The MTF is so good it is rediculous :)
There are other signs that lens is better than just good.
Sure sure. But how is that unique to the RF mount? Zeiss Otus lenses are better than just good, mirrorless mount not required.
 

neuroanatomist

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Well... I'd argue that if you consider the system, the R+RF35 is smaller than the R+adapter+EF35/2IS. Not by a huge amount, but it's smaller, and they added semi-macro and a third of a stop in that moderately smaller space. Was that enabled by the RF mount? Like you say, it's hard to prove, but it's possible.
The (as yet unsubstantiated) claim is that the RF mount allows smaller lenses...not that the RF mount allows a smaller overall system length when adapting a lens not designed for the R camera. The RF 35/1.8 IS is 2.5” long, the EF 35/2 IS is 1.7” long.

Thanks for catching that red herring, but please throw it back in the water, it already smells putrid.
 

QuisUtDeus

EOS 80D
Feb 20, 2019
115
80
The (as yet unsubstantiated) claim is that the RF mount allows smaller lenses...not that the RF mount allows a smaller overall system length when adapting a lens not designed for the R camera. The RF 35/1.8 IS is 2.5” long, the EF 35/2 IS is 1.7” long.

Thanks for catching that red herring, but please throw it back in the water, it already smells putrid.
I knew you'd somehow find a way to be negative about that. :)

I never made such a claim, so I have nothing to defend on that front. I do care what fits where, and what I posted has a practical effect on that front. You're free to argue with other people about whatever you like.
 

timmy_650

EOS RP
Dec 20, 2012
275
12
The (as yet unsubstantiated) claim is that the RF mount allows smaller lenses...not that the RF mount allows a smaller overall system length when adapting a lens not designed for the R camera.
Isn't the RF 70-200 f2.8 IS a good example of that? We have seen the lens and it is smaller.
 

neuroanatomist

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Isn't the RF 70-200 f2.8 IS a good example of that? We have seen the lens and it is smaller.
Nope. It’s an extending zoom lens, so of course it’s smaller when retracted. Based on the patent, when extended it’s actually longer than the EF 70-200/2.8. Nothing unique to RF about an extending zoom design, no reason Canon couldn’t make an EF 70-200 L with an extending design like the EF 70-300 L.
 

SecureGSM

2 x 5D IV
Feb 26, 2017
1,233
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The lens itself is unique, but that doesn’t preclude the possibility of such a design for a longer flange. Sigma is also more constrained on their ability to price lenses, which certainly would have an impact on what they could design. As I said, maybe. Without the lens design experience, qualifications, and engineering/software tools of design teams across multiple manufacturers, how can you say for sure?


Sure sure. But how is that unique to the RF mount? Zeiss Otus lenses are better than just good, mirrorless mount not required.
Please note : “And / or “ in my original post.
RF 85/1.2 is amazing but not unique. Therefore either of us is correct.
RF 28-70/f2.0 is unique but not amazing wide open ;)
The rest of your statement is only partially valid :) I suggest that we continue discussion offline But reality is: such a lens was impractical to manufacture for EF Mount according to multiple statements of Sigma’s CEO. I have no doubt that he knows what he is talking about.
On an unrelated note, I enjoy this conversation but let’s keep it to the point. Thank you.
 

degos

EOS RP
Mar 20, 2015
200
122
The rest of your statement is only partially valid :) I suggest that we continue discussion offline But reality is: such a lens was impractical to manufacture for EF Mount according to multiple statements of Sigma’s CEO. I have no doubt that he knows what he is talking about.
Impractical, not impossible. And I'd call the RF 24-70 f2 pretty much impractical for most photographers, too, other than studio shooters or 'photodrivers' who keep it on the seat beside them and just hop out of their car to take shots of the vista they saw on Instagram. Of course they'll probably be shooting at f8 anyhow...

Sigma did the hardest part of work with the 24-35 for EF; bending the light rays into the longer flange.
 

mb66energy

EOS 6D MK II
Dec 18, 2011
1,268
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Germany
www.MichaelBockhorst.de
Arrgh, please no variable aperture. I would like to switch to an RF wide zoom but I'm probably going to stick with my EF on the adapter if I can't get 1. IS 2. constant aperture (f/2.8 would be super but f/4 acceptable) 3. 77mm filter thread (the forthcoming holy trinity lenses don't appear to be, according to the images published). Right now everything in my bag is 77mm so I have no step-up rings or duplicate filters and I'm loving it.
Maybe use the EF 16-35 with filter adapter ... you have constant f/4.0, one filter for all EF lenses and a slightly larger combo. And the lens will work on EF, EF-S, EF-M compatible cameras.
 

mb66energy

EOS 6D MK II
Dec 18, 2011
1,268
180
Germany
www.MichaelBockhorst.de
What would be the EF counterpart - the EF 17-40mm f/4L?

I would expect the combination of shorter flange distance and f-stop slower on the wide side to allow for a smaller lens.
I had the same thought. Naturally a smaller focal length at the same entrance pupil makes a lower stop number. But corrections in ultrawides need large elements - why not reduce the aperture to the lower end to reduce lens aberrations (like spherical aberration).

I see 17mm as a focal length where you want depth of field and hand holding problems are reduced by shorter focal lengths - no problem with larger f-stop numbers wide open.
A 35mm f/5.6 would be next to useless for me - I would like to see f/2.8 or at least f/4.0 to have a minimum chance for blurred backgrounds at small focusing distances.

A 17-35 f/5.6 ... f2.8 would be an interesting ultra wide lens for me.
 

SecureGSM

2 x 5D IV
Feb 26, 2017
1,233
258
Impractical, not impossible. And I'd call the RF 24-70 f2 pretty much impractical for most photographers, too, other than studio shooters or 'photodrivers' who keep it on the seat beside them and just hop out of their car to take shots of the vista they saw on Instagram. Of course they'll probably be shooting at f8 anyhow...

Sigma did the hardest part of work with the 24-35 for EF; bending the light rays into the longer flange.
you are not an event shooter, are you? :) some venues are pretty poor lit and you have to keep you shutter speed above the certain level and you are not allowed to use flash.. dance floor, churches, some presentations where flash isn't allowed to use.. what do you do? you break out you F1.4 primes...
with F2.0 zoom I can get away and keep shooting at ISO 6400 which is a massively better than iso 12800 at F2.8

P.S. Who on earth shoots in studio wide open? stopped down to F8.0 most modern Canon zooms are amazing. You do need this lens in studio. obviously you are not a studio shooter either

P.S.2.: it is easier to bend light rays into a longer flange if you think about it ;)
 
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neuroanatomist

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Jul 21, 2010
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But reality is: such a lens was impractical to manufacture for EF Mount according to multiple statements of Sigma’s CEO. I have no doubt that he knows what he is talking about.
Did you note that I mentioned Sigma’s price constraints? Did the Sigma CEO say an f/2 zoom with more range couldn’t be done? No. Impractical could easily mean insufficient market for the necessary price.

I wonder...if/when Canon comes out with an RF 24-70/2.8 IS, will people claim the RF mount made it possible? :rolleyes:
 

SecureGSM

2 x 5D IV
Feb 26, 2017
1,233
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Did you note that I mentioned Sigma’s price constraints? Did the Sigma CEO say an f/2 zoom with more range couldn’t be done? No. Impractical could easily mean insufficient market for the necessary price.

I wonder...if/when Canon comes out with an RF 24-70/2.8 IS, will people claim the RF mount made it possible? :rolleyes:
Sigma CEO said that 18-35/1.8 was a pure luck and they avoided a failure to design such a lens by a slim margin.
24-70/2.8 IS lenses are available in EF mount right now.

I do not recall a single 85/1.2 IS lens available to date in EF Mount.
I do not recall a single x2.5 f2.0 standard zoom lens available in DSLR world. Not even in a APS-C let alone FF

Sigma CEO’s reaction to RF 28-70 F2.0 lens announcement was: “very impressed and a little jealous”. Quite an emotional statement for a Japanese leader.