# Patent: Very small large aperture zoom lens optical formulas



## Canon Rumors Guy (Jun 21, 2022)

> Canon has published a pretty interesting optical design patent for large aperture zoom lenses. The two designs in this patent are pretty interesting.
> Canon’s goal in this patent
> To provide a zoom lens having a short total length and a small size but having high optical performance, and an image pickup apparatus having the same.
> As you can see, these lens designs use the “reverse” zoom design like the original EF 24-70mm f/2.8L USM. This probably helps in reducing the length and size of the lens. As you can see, the image height changes when zooming in and out.
> ...



Continue reading...


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## neuroanatomist (Jun 21, 2022)

Looks like non-L f/2.8 zooms. Interesting. Not lenses I’d buy, but interesting nonetheless.


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## Bob Howland (Jun 21, 2022)

Small and light!? The original 24-70 was big and heavy. At least mine is.


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## bbasiaga (Jun 21, 2022)

so a 28-60 or 28-70 f2.8 lens? I'd take one compact like that instead of a larger 24-70 2.8. 

-Brian


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## mdcmdcmdc (Jun 21, 2022)

How does “image height” relate to image circle? Is it the diameter? The radius? Or is it the height of a rectangle with an assumed 3:2 aspect ratio?


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## Deleted member 381342 (Jun 21, 2022)

I really liked that the original EF 24-70 L started of at the right end then you could zoom out. It was counter intuitive at first, but for me I used it most frequently at the long end.


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## Tom W (Jun 21, 2022)

If the image height doesn't cover the full frame sensor, how does Canon propose to accomplish a full image?


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## jam05 (Jun 21, 2022)

So why is this important to the average consumer? Not as if someone is going to manufacture or 3D a lens. Besides it is one of hundreds if not thousands of Canon patents.


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## jam05 (Jun 21, 2022)

Now lets track down the status of those AF tilt shift lenses. Its now going on July, and not a peep and we focus attention on patents. Lets find the testers of those prior mentioned tilt shift lenses. Or one may suspect those were more BS patents and rumor fodder.


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## peters (Jun 21, 2022)

Tom W said:


> If the image height doesn't cover the full frame sensor, how does Canon propose to accomplish a full image?


Maybe a video centered lense, that would work in 16:9 (or maybe only 21:9 or anamorph). 
Such a lense could cover 16:9 in fullframe or the entire image of an S35 area.


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## JaydenEricBeaudoin (Jun 21, 2022)

Dang, here I was hoping for an f2 trinity lens.


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## Bahrd (Jun 21, 2022)

mdcmdcmdc said:


> How does “image height” relate to image circle? Is it the diameter? The radius?


The latter: 36² + 24² ~ 43².


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## mxwphoto (Jun 21, 2022)

This would be Canon pulling a Tamron, 80-90% focal length at much reduced size for given aperture. Probably will not include IS to keep size and weight down if they do come out with it.


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## Bonich (Jun 21, 2022)

Tom W said:


> If the image height doesn't cover the full frame sensor, how does Canon propose to accomplish a full image?


Simple as it is: The image height corresponds with APS sensor size.


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## bbasiaga (Jun 21, 2022)

Tom W said:


> If the image height doesn't cover the full frame sensor, how does Canon propose to accomplish a full image?


I'm guessing that it'll be heavily vignetted without correction in the corners at the wide end. The 24-240 lens, for example, has an image height of ~19mm at 24mm (there were a number of similar patents for that range, all in the upper 18s to lower 19s). It works very well with digital correction, as these likely would. 

-Brian


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## efmshark (Jun 21, 2022)

RF-S lenses?


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## neuroanatomist (Jun 21, 2022)

Photo Bunny said:


> I really liked that the original EF 24-70 L started of at the right end then you could zoom out. It was counter intuitive at first, but for me I used it most frequently at the long end.


The advantage to that 'reverse' zoom is that the lens hood is effective throughout the zoom range, instead of only at the wide end.


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## neuroanatomist (Jun 21, 2022)

Tom W said:


> If the image height doesn't cover the full frame sensor, how does Canon propose to accomplish a full image?


By stretching the image. The geometric distortion at the wide end is substantial, and correcting that distortion results in the 'missing' (mechanically vignetted) corners being filled in. That geometric correction is forced (in-camera and in DPP) for lenses like the RF 16/2.8, RF 24-240 and RF 14-35/4L.

There was a recent front page post claiming a new set of patents were APS-C 'pancake' primes, based on an image height of 18.2mm. It turns out that the patented 16/2.8 in that post is not a new APS-C pancake lens, but rather is the existing RF 16mm f/2.8 lens that you can buy today (which isn't a pancake, but the length in the patent is consistent with the length of the production lens).



Bonich said:


> Simple as it is: The image height corresponds with APS sensor size.


The closest is actually APS-H, not APS-C. These are full frame RF lens designs. Consider what we know of Canon – is it more likely they'd make a lens with a larger image circle than necessary, or a smaller image circle than necessary that gets corrected by software (along with forcing that correction in-camera and in DPP)? The latter, of course.


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## mdcmdcmdc (Jun 21, 2022)

Bahrd said:


> The latter: 36² + 24² ~ 43².


If image height == radius, it needs to be half that, or 23.6 mm, to cover FF.


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## neuroanatomist (Jun 21, 2022)

mdcmdcmdc said:


> If image height == radius, it needs to be half that, or 23.6 mm, to cover FF.


Your math is wrong. The diameter of the FF image circle is ~43.2mm, and the image height for a FF image circle is ~21.6mm (not coincidentally, the image height at the longer focal lengths of the lenses in these patents is 21.64mm).


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## mdcmdcmdc (Jun 21, 2022)

neuroanatomist said:


> Your math is wrong. The diameter of the FF image circle is ~43.2mm, and the image height for a FF image circle is ~21.6mm (not coincidentally, the image height at the longer focal lengths of the lenses in these patents is 21.64mm).


My math was right, it’s my typing that was wrong! 21.6 mm, agreed.


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## t.linn (Jun 21, 2022)

jam05 said:


> So why is this important to the average consumer? Not as if someone is going to manufacture or 3D a lens. Besides it is one of hundreds if not thousands of Canon patents.


If you dislike rumors, perhaps you should not visit rumor sites. This stuff doesn't have to be important. It is okay if it is simply interesting.


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## neuroanatomist (Jun 21, 2022)

t.linn said:


> If you dislike rumors, perhaps you should not visit rumor sites. This stuff doesn't have to be important. It is okay if it is simply interesting.


He would rather visit CanonRu*ME*rs, the site where only rumors you personally care about are posted.


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## Punio (Jun 21, 2022)

Anyone know if there is an upcoming event where we can possibly expect new lenses?


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## vangelismm (Jun 22, 2022)

Just do the 24 70 f/4.....


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## mb66energy (Jun 22, 2022)

vangelismm said:


> Just do the 24 70 f/4.....


And an RF-S 15-60 f/4 for those who rely on smaller sensor sizes


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## Blue Zurich (Jun 22, 2022)

Small Large....


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## yungfat (Jun 25, 2022)

There’s always a trade off when bringing camera for vacation, weather sealed and large aperture lens I si going to be heavy and huge, really hope canon can come out something light with large aperture and weather sealed lens.


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## entoman (Jul 10, 2022)

Canon’s goal in this patent​


> To provide a zoom lens having a short total length and a small size but having high optical performance, and an image pickup apparatus having the same.


Mystified and amused by the terminology... 

How can the "image pickup apparatus" (presumably the camera sensor) have the "same" (i.e. a short total length, small size and high optical performance?

Something has been lost in the translation here - if they are not referring to the sensor, what exactly do they mean by "image pickup apparatus"?


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## neuroanatomist (Jul 10, 2022)

entoman said:


> Canon’s goal in this patent​
> Mystified and amused by the terminology...
> 
> How can the "image pickup apparatus" (presumably the camera sensor) have the "same" (i.e. a short total length, small size and high optical performance?
> ...


Image pickup apparatus = camera.


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