Canon Patents

Patent: Canon RF 13-21mm f/2.8L

A patent showcasing an RF 13-21mm f/2.8 optical formula has appeared in Japan.

Canon RF 13-21mm f/2.8 embodiment:

  • Zoom ratio: 1.58
  • Focal length: 13.40mm  17.30mm  21.20mm
  • F number: 2.88 2.88 2.88
  • Half angle of view: 58.23 51.35 45.58
  • Image height: 21.64mm  21.64mm  21.64mm
  • Lens length: 150.15mm  136.89mm  130.04mm
  • Back focus: 20.96mm  25.13mm  29.31mm

I doubt this specific optical formula will become a consumer product, but it is probably part of the development for an ultra-wide-angle RF mount lens that we expect to see sometime in 2020.

tron

EOS R5
CR Pro
Nov 8, 2011
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Not interesting! It is much less practical than a 15-35 (and yes I know that even 1mm at these focal lengths can make a difference). There are also so many 14mm lenses (with one of these at 1.8) that can be used with the adaptor but the main rival of this lens is the RF15-35 (which by the way has IS). Now if they make a f/2 zoom or a f/1.4 prime at say 13mm now that would be something to talk about!
 
Jan 8, 2020
2
3
I’m still learning about these patents... what does it mean when the back focus is variable? Does the back element move in this case?
 

twoheadedboy

EOS R5
CR Pro
Jan 3, 2018
189
277
Kenosha, WI
There were RF 10-24 f/4 and RF 14-28 f/2.0 patents recently. Intresting. We won't see all 3 of them, I guess. 13-21 seems a bit of a small zoom ratio to me. I'd prefer the 10-24 f/4, I believe.
I want the f/4 IS zoom that goes the widest and still can take regular 72mm filters. I'm willing to sacrifice on the long end as long as it can get to 24mm.
 

SecureGSM

2 x 5D IV
Feb 26, 2017
2,376
1,245
Not interesting! It is much less practical than a 15-35 (and yes I know that even 1mm at these focal lengths can make a difference). There are also so many 14mm lenses (with one of these at 1.8) that can be used with the adaptor but the main rival of this lens is the RF15-35 (which by the way has IS). Now if they make a f/2 zoom or a f/1.4 prime at say 13mm now that would be something to talk about!
Unless they managed to makes this lens filterable... somehow. That would be huge.

p.s. anything over 4 stops of vignetting in extreme corners wide open at 13 mm excluding, please. :)
 

CanonFanBoy

Real men single speed.
CR Pro
Jan 28, 2015
5,222
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Irving, Texas
+ does it always have to be in classic and repeated ranges? Perhaps they found a formula for excellent IQ through the range.
It is funny to me that I have read over and over on this forum that Canon is too conservative, doesn't innovate, etc. Yet every single time Canon does something new that is out of the ordinary people start harping, "It's never been done that way before so it can't possibly be a good idea." I don't know whether or not this lens will ever get released, but one would think people would at least wait and see what it is all about before twisting and shouting so. Not saying anyone here is doing that yet, but it will happen... especially if it gets released. I don't shoot landscapes, interiors, or astro anymore, but I would think this is what such a specialty lens is for.
 

Antono Refa

EOS R
Mar 26, 2014
1,131
313
Not interesting!
To whom?

Customers would probably be interested in either the 15-35mm f/2.8L IS or the F 10-24mm f/4L, but Canon might be interested in it for the IP or some aspect other than your interest and entertainment.

Also, note the patent and the lens that actually comes out might be two different things. IIRC, Canon had a patent for a 10mm prime that eventually came out as the 11-24mm f/4L zoom. Or was it the TS-E 17mm f/4L?
 

SecureGSM

2 x 5D IV
Feb 26, 2017
2,376
1,245
Sounds a bit like my Tokina 11-16mm f2.8.
It seems like a narrow range but it does make quite a bit of difference.
I use this for 4k video on my R, and it does a really good job.
Tokina is a crop sensor lens though. 13-21 on FF is quite a bit wider. If filterable, could make into a trinity candidate lens for events or real estate / interior folks.
 

tron

EOS R5
CR Pro
Nov 8, 2011
4,728
964
To whom?

Customers would probably be interested in either the 15-35mm f/2.8L IS or the F 10-24mm f/4L, but Canon might be interested in it for the IP or some aspect other than your interest and entertainment.

Also, note the patent and the lens that actually comes out might be two different things. IIRC, Canon had a patent for a 10mm prime that eventually came out as the 11-24mm f/4L zoom. Or was it the TS-E 17mm f/4L?
To me at first! I did not say not interesting to everyone. It is an opinion site. There is no absolute truth. Feel free to prefer it if it becomes available. And of course it is better to have more choices than less. As another forum user mentioned it would be interesting if t would be smaller than 15-35.
 

slclick

Pinhole
Dec 17, 2013
4,224
2,239
It is funny to me that I have read over and over on this forum that Canon is too conservative, doesn't innovate, etc. Yet every single time Canon does something new that is out of the ordinary people start harping, "It's never been done that way before so it can't possibly be a good idea." I don't know whether or not this lens will ever get released, but one would think people would at least wait and see what it is all about before twisting and shouting so. Not saying anyone here is doing that yet, but it will happen... especially if it gets released. I don't shoot landscapes, interiors, or astro anymore, but I would think this is what such a specialty lens is for.
+!

I owned the Sigma 24-35 Art for a bit and loved it for the type of shooting I enjoyed with it. It was and still is ridiculed in the camera world.

It was like having 3 primes in one, not such a bad thing. Shorter the zoom range, more consistency across the range.