Canon Patents

Patent: Canon RF 135mm f/1.4L DS USM optical formula

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More optical formulas for large aperture RF mount prime lenses have appeared. This new patent showcases some RF mount prime lenses that utilize Defocus Smoothing, which first appeared in the RF 85mm f/1.2L USM DS.

Canon RF 24mm f/1.4L USM DS

  • Focal length: 24.55mm
  • F-Number: 1.45
  • Half angle of view: 41.39°
  • Image height: 21.64mm
  • Overall length: 119.13mm
  • BF: 38.01mm

Canon RF 50mm f/1.4L USM DS

  • Focal length: 52.13mm
  • F-Number: 1.45
  • Half angle of view: 22.54°
  • Image height: 21.64mm
  • Overall length: 85.51mm
  • BF: 37.71mm

Canon RF 135mm f/1.4L USM DS

  • Focal length: 131.00mm
  • F-Number: 1.41
  • Half angle of view: 9.38°
  • Image height: 21.64mm
  • Overall length: 182.28mm
  • Back focus: 13.87mm

H. Jones

Aug 1, 2014
I won't be surprised at all if the 135mm F/1.4 also gets released as a DS option.

Someone mentioned sequential lens IDs in certifications are often variants of the same lens, right? Canon could be gearing up to announce the 135mm f/1.4 and its DS counterpart as "two" lenses.

I do feel like we need a fast 35mm before we get another portrait lens, but this will be one heck of a statement lens with DS at that aperture and focal length.

Would be interested to see if DS really even makes all that much of a difference at 24mm. I can't imagine the bokeh is *that* much better.


Dec 17, 2013
Why do I use an EF-RF adapter on my R6?

135 f/2L This is a lens which many have attempted to better but sharpness isn't everything (looking at you Siggy) and it may well be the last EF lens I will own if I replace all the rest with RF versions. (Oh and it makes a great 2 lens combo with the RF 35)


EF 800L
May 29, 2019
If it performs like or better than 135 f2 L it would be an instant pick up for me for astrophotography and portraits,
Ego says they have to do better than the Sigma 135 art (f/1.8) . If Canon can make that lens with very little coma, it will sell like hotcakes in the astro world.


Birds in Flight Nutter
Jul 26, 2020
Orewa , New Zealand
As the owner of a Canon EF 135 f/2 for 15 years, I can't think of a single instance where f/1.4 would have been a great advantage, especially if the cost of the f/1.4 lens is $5000+.
I'll stick with my EF 135mm f/2.8 soft focus lens which cost me USD 240 (NZD 370) including shipping and sales tax on eBay.
It's super light and an amazing lens for the money (and the soft focus feature is fun to play with)