Canon Patents

Patent: Canon RF 14-35mm f/4L IS USM

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Yesterday I posted a patent showing the optical formulas for both an RF 15-35mm f/4L and an RF 16-35mm f/4L. I noted that an RF 14-35mm f/4L is rumored to be coming in 2021, and I did wonder aloud if that was a type, but it appears Canon is definitely working on an RF 14-35mm f/4L optical formula.

It looks like this design of an RF 14-35mm f/4L has an internal zoom and will likely have IS as well.

Japan Patent Application 2020-190696

Canon RF 14-35mm f/4L
Focal Length 14.80mm 21.58mm 32.95mm
F Number 4.1 4.1 4.58
Half Angle of View 55.62° 45.07° 33.37°
Image Height 21.64mm 21.64mm 21.64mm
Total Lens Length 244.83mm 244.83mm 244.88mm
Backfocus 16.76mm 16.76mm 16.76mm
Canon RF 17-40mm f/4L
Focal Length 17.33mm 23.76mm 38.46
F Number 4.1 4.1 4.1
Half Angle of View 51.31° 42.32° 29.36°
Image Height 21.64mm 21.64mm 21.64mm
Total Lens Length 140.59mm 135.90mm 140.61mm
Backfocus 26.31mm 26.31mm 26.31mm

While this patent pertains to underwater housings for the optical formulas in the patent, the formula for this lens is quite detailed. Canon News discovered this patent that also shows some rather large RF prime lenses, which you can read about at Canon News.

Note: The image for this post is the Canon RF 15-35mm f/2.8L IS USM

xwxw

I'm New Here
Nov 3, 2020
14
20
244.83mm? Even deducting the 20m flange, that would be 224mm long, putting this past the RF 100-500 which is only 208mm.
 

fred

I'm New Here
Oct 9, 2020
22
18
"It looks like this design of an RF 14-35mm f/4L has an internal zoom."

If true, it is already better than the Nikon Z 14-30 F4 S.
 

Maximilian

The dark side - I've been there
CR Pro
Nov 7, 2013
3,472
2,296
Germany
If this is continuing the increase in preformance/IQ compared to the EF 16-35mm f/4L IS USM I'll raise my hat to Canon for their R&D department.
 
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padam

EOS R
Aug 26, 2015
1,233
893
If this is continuing the increase in preformance/IQ compared to the EF 16-35mm f/4L IS USM I'll raise my hat to Canon for their R&D department.
If it is only just as sharp at equivalent focal lengths while being wider as well as lighter and more compact, it is a big advancement.
They will also take care of of some other minor flaws, namely flaring, and the noisy AF during video recording.

But it's also going to cost twice as much compared to the EF lens, so it won't be as popular. But due to all camera sales continually decreasing, it's not designed to be anyway.
 
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xwxw

I'm New Here
Nov 3, 2020
14
20
You are correct. This may well be indicating the housing of the underwater unit which understandably would need to be much larger to allow the 14mm wide angle. Anyone could use your math to guess how long the lens may be? ;) I would guess about 120mm, which is about 10mm longer than the 16-35 F4.



1606511572915.png
 

LensFungus

EOS 90D
Apr 8, 2017
127
534
You are correct. This may well be indicating the housing of the underwater unit which understandably would need to be much larger to allow the 14mm wide angle. Anyone could use your math to guess how long the lens may be? ;) I would guess about 120mm, which is about 10mm longer than the 16-35 F4.



View attachment 194188
D looks like the cannonball from Super Mario.
 

Bahrd

Red herrings...
Jun 30, 2013
169
119
I also have mathematical issues. Canon's cripple* rounding.

* When a distribution is skewed, such a rounding can produce a proper outcome... ;)

PS
I wouldn't blame Canon (yet) anyway... There is no direct designation of the lens' parameters in the patent. The headlines seem to rather be our host's (and the CN guy) translation/interpretation.
 

sanj

EOS R5
Jan 22, 2012
3,802
671
I personally have ethical issues with Canon calling it a 14mm when it is actually 14.8mm. It would be more honest to call it a 15-34 zoom when one looks at the actual numbers.
It would be prudent to hold the judgement until after the launch. This is just a rumour.
 
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Ale_F

6D - 7D
Nov 22, 2018
77
52
"It looks like this design of an RF 14-35mm f/4L has an internal zoom."

If true, it is already better than the Nikon Z 14-30 F4 S.
Despite the two RF70-200 are compact, I prefer the internal zoom like the EF17-40 and others.
 
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SwissFrank

from EOS 1N to R
Dec 9, 2018
581
317
I used to shoot with the f/2.8 trinity 17-200mm, then f/5.6 out to 400mm with a TC or two. Then I'd have f/1.4 primes for special shots.

With the advent in IS, relatively clean shots at high ISO, AF that doesn't need big apertures, and viewfinders that don't need big apertures for brightness, now I think we can move to an f/4 trinity. 14-35/4, 24-105/4, and 100-500/4.5-7.1 in three lenses with no TC seems like a general improvement: lighter, cheaper, longer rand wide to narrow, perhaps a bit less lens-changing. (Really, f/2.8 even when you got it in focus was not that deep of focus, so I have lots of suboptimal photos thanks to that.) Then we can increase the primes a half-stop or more: 35/1.2, 50/1.2, 85/1.2, 135/1.4. I expect a 24/1.2 as well. So when you want bokeh and to separate out your subject from the background, you can do moreso now with the bigger primes. When that's not your goal, you still have more convenient shooting with the f/4.

But to the extent you found 70mm f/2.8 to be bokeh-ish, that's due to a 25mm aperture. 100mm at f/4 is actually a 26.5mm aperture, and the background is yet more magnified so it's easier to slightly change angles and get a background you want. So even though the f-stop is 4 not 2.8, the bokeh is the same or better. Likewise 500mm at f/7.1 is a 70.5mm aperture, very similar to a 200mm at 2.8, 280mm at f/4, or 400mm at f/5.6. So you still have the bokeh power (or more) of the f/2.8 trinity with this new trinity.
 
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