Patent: Canon RF 50mm f/1.4 USM and other primes

Canon Rumors Guy

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Jul 20, 2010
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A new Canon Japan patent shows the optical formulas for various RF 50mm f/1.4 designs as well as an RF 35mm f/1.4. This patent deals with increasing focusing speed when using lens designs with large diameter elements.
I don’t think any of these optical formulas will become products, so the dream of a new 50mm f/1.4 from Canon probably won’t be coming true any time soon.








RF 50mm f/1.4

RF 50mm f/1.4

RF 50mm f/1.8



Focal length

51.50mm...

Continue reading...
 
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SwissFrank

from EOS 1N to R
Dec 9, 2018
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These designs somehow don't look like real designs, but rather examples of trying to have lots of heavy elements on purpose... I've never seen so many cemented doublets
 

melgross

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Nov 2, 2016
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Remember the days when a 50 f1.8-2.0 was a basic Gaussian 6 element design, and the bigger, more expensive f1.4 had 1 more element? The f1.4 also had higher quality. My 50 f1.4 FD was considered to be a superb lens. I suppose today it would fail every test. All of my FD lenses, the pro models, are considered as tiny today.

though my 100mm f2.8 is still one of the sharpest lenses I’ve ever had.
 

Antono Refa

EOS R
Mar 26, 2014
1,269
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My 50 f1.4 FD was considered to be a superb lens. I suppose today it would fail every test.

The standards have changed in the past few decades. Technically, sensors have more details than most films, and the standard of living has raised, and people can and do print larger.
 

DJL329

EOS R5
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Aug 26, 2010
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An RF 50mm f/1.4???

Take My Money.gif
 

melgross

EOS RP
Nov 2, 2016
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The standards have changed in the past few decades. Technically, sensors have more details than most films, and the standard of living has raised, and people can and do print larger.
Yes, that was the point. My company used to process Kodachrome. We had our own pro process. I used to write for Kodak’s Lab Notes. I’m about as familiar with this as anyone. Kodachrome, according to Kodak, was equivalent to about 14-18MP. So that gives an idea. But that 100 f2.8 is still a very sharp lens. I’ve got an adapter for FD lenses on the EOS mount. Unfortunately, you can’t focus to infinity with it, but otherwise, you can use those lenses. On my 5D mk IV, it’s still pretty damn sharp. Surprising, but true.
 

Sporgon

5% of gear used 95% of the time
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Kodachrome, according to Kodak, was equivalent to about 14-18MP.
Which Kodachrome ? The only one I have found to come close to 14 mp in resolution and 18mp in colour definition was Kodachrome 25. (35 mil of course).

But I've also found that fine grain 35mm film is as brutal on lenses and technique as a 5DS when you start scanning and outputting to the same kind of sizes we routinely do today.
 

melgross

EOS RP
Nov 2, 2016
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Which Kodachrome ? The only one I have found to come close to 14 mp in resolution and 18mp in colour definition was Kodachrome 25. (35 mil of course).

But I've also found that fine grain 35mm film is as brutal on lenses and technique as a 5DS when you start scanning and outputting to the same kind of sizes we routinely do today.
K-25.

nah, film is easy, by today’s standards. And by the way, lens manufacturers used to lie all the time about flat field (Leica, I’m looking at you!). Film in film gates where the back plate doesn’t clamp down on the film, isn’t flat. Think about everything that film is and what the requirements for mechanical operation is, and you’ll understand why. It’s a major reason why film lenses can be fairly sharp in the center, and so bad everywhere else, for digital. That’s for lower rez digital. We began, in my lab, to see that for 6MP.
 

dsut4392

EOS M6 Mark II
Jul 31, 2014
81
35
a Compact 50 f1.4 usm, weather-sealed ....please!!!
I don't even care about USM as long as AF is accurate, just make it compact and give it good bokeh. an RF version of the Sigma 50/1.4 EX would be perfect.
 

koenkooi

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Feb 25, 2015
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I hoped for an EF 50mm f/1.4 IS USM along the lines of the 24-28-35mm trio upgrade since, well, the upgrade. Apparently its not in the cards.

I don't think we'll be seeing USM in non-L primes from now on.
 

Del Paso

M3 Singlestroke
Aug 9, 2018
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K-25.

nah, film is easy, by today’s standards. And by the way, lens manufacturers used to lie all the time about flat field (Leica, I’m looking at you!). Film in film gates where the back plate doesn’t clamp down on the film, isn’t flat. Think about everything that film is and what the requirements for mechanical operation is, and you’ll understand why. It’s a major reason why film lenses can be fairly sharp in the center, and so bad everywhere else, for digital. That’s for lower rez digital. We began, in my lab, to see that for 6MP.
That's exactly what I noticed with an old Leica M Summicron 35 f2 , extremely good on Kodachrome, but marshmallow soft corners on Leica digital bodies under f8. Same applies to the Leica R 28mm f2,8.
Yet, the 50 M, 75 M, 90 M, 135 M and all the other Leica R APO vintage lenses are still tack sharp, even in the extreme corners.
Even most of my Olympus lenses were unusable for digital... and got sold:cry:
 

justaCanonuser

Grab your camera, go out and shoot!
Feb 12, 2014
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Frankfurt, Germany
Finally, a new 50mm f 1.4! High time, the EF version is really old design, very soft wide open ... I waited many years for a new EF version in vain, now, with the new mount, it doesn't come as a surprise.
 

melgross

EOS RP
Nov 2, 2016
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That's exactly what I noticed with an old Leica M Summicron 35 f2 , extremely good on Kodachrome, but marshmallow soft corners on Leica digital bodies under f8. Same applies to the Leica R 28mm f2,8.
Yet, the 50 M, 75 M, 90 M, 135 M and all the other Leica R APO vintage lenses are still tack sharp, even in the extreme corners.
Even most of my Olympus lenses were unusable for digital... and got sold:cry:
What’s interesting is how manufacturers handled backfocus. Back then, with manual, analog cameras, there was no backfocus adjustments. A manufacturer decided where to put that main focus at. Sometimes, it was closer to the front, sometimes to the rear. Some lenses were sharper with thinner b/w film, and some with thicker color film. Some were even aimed at thick Kodachrome.

by the way, apochromatic lenses aren’t necessarily sharper, nor do they always have flat field. It just means that three colors focus on the same plain, curved or flat. Stopping down a couple of stops, as always, results in better performance across the frame.
 
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