Patent: RF mount constant aperture superzoom lenses, including an RF 28-280mm f/2.8

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    patentsuperzoom - Patent: RF mount constant aperture superzoom lenses, including an RF 28-280mm f/2.8

    Canon News has uncovered a patent for various super zoom optical formulas, and they're all for the RF mount except for one that appears to be for EF-S.

    Canon RF 28-135mm f/4:

    • Focal length: 28.84mm 80.09mm 135.75mm
    • F-number: 4.12 4.12 4.12
    • Half angle of view: 33.13° 15.12° 9.06°
    • Image height: 18.82mm 21.64mm 21.64mm
    • Total lens length: 167.97mm 167.97mm 167.97mm
    • BF: 27.78mm 27.78mm 27.78mm

    Canon RF 24-170mm f/4:

    • Focal length: 24.72mm 99.78mm 166.47mm
    • F-number: 4.12 4.12 4.12
    • Half angle of view: 37.29° 12.23° 7.40°
    • Image height: 18.82mm 21.64mm 21.64mm
    • Total lens length: 236.70mm 236.70mm 236.70mm
    • BF: 23.98mm 23.98mm 23.98mm

    Canon RF 28-280mm f/2.8:

    • Focal length: 27.81mm 146.83mm 269.60mm
    • F-number: 2.88 2.88 2.88
    • Half angle of view: 34.09° 8.38° 4.59°
    • Image height: 18.82mm 21.64mm 21.64mm
    • Total lens length: 340.47mm 340.47mm 340.47mm
    • BF: 32.97mm 32.97mm 32.97mm

    Canon EF-S 17-170mm f/3.5:

    • Focal length: 17.51mm 83.09mm 169.77mm
    • F-number: 3.61 3.60 3.61
    • Half angle of view: 36.33° 10.10° 4.98°
    • Image height: 12.88mm 14.80mm 14.80mm
    • Total lens length: 248.91mm 248.91mm 248.91 mm
    • BF: 40.40mm 40.40mm 40.40mm
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    54 comments

    1. Wow, that 28-280mm f/2.8 is almost the length of a 400mm f/2.8, but it's an internal zoom.

      I honestly could imagine this lens becoming a reality at some point, no joke. Imagine the 120-300mm f/2.8 lenses of other companies but able to go all the way out to 28mm. That would be an *absolutely* killer sports lens, and the size wouldn't be an issue as the 120-300mm f/2.8 lenses are already 297.6mm in length, so only 40mm shorter.

      I know not all patents become a reality, but I definitely think there's a market for this in sports/wildlife/news that would turn this into a big deal. 28-200mm f/2.8 would be great on its own, but I think Canon having this go out to 280mm makes it a lot more likely people would deal with the extra weight.
    3. I noticed that the image height is reduced at the wide end on these lenses. Does that mean that post-processing will be used to s t r e t c h the corners to match the indicated focal length?
    5. Wow, that 28-280mm f/2.8 is almost the length of a 400mm f/2.8, but it's an internal zoom.

      I honestly could imagine this lens becoming a reality at some point, no joke. Imagine the 120-300mm f/2.8 lenses of other companies but able to go all the way out to 28mm. That would be an *absolutely* killer sports lens, and the size wouldn't be an issue as the 120-300mm f/2.8 lenses are already 297.6mm in length, so only 40mm shorter.

      I know not all patents become a reality, but I definitely think there's a market for this in sports/wildlife/news that would turn this into a big deal. 28-200mm f/2.8 would be great on its own, but I think Canon having this go out to 280mm makes it a lot more likely people would deal with the extra weight.
      takemymoney.jpg
    6. I noticed that the image height is reduced at the wide end on these lenses. Does that mean that post-processing will be used to s t r e t c h the corners to match the indicated focal length?

      yes. Craig didn't copy that over from my site, but yes, all these lenses have stretching happening on the wide end.
    7. Looks like some very versatile lenses but honestly nothing I would expect brilliant image quality from...

      I can imagine though that these will make the EOS R* system a cash cow for Canon... in the middle of the shrinking market. ;)
    8. yes. Craig didn't copy that over from my site, but yes, all these lenses have stretching happening on the wide end.

      I have mixed feelings about the "stretching" method. On the one hand, if you rarely use the wide end and just want to grab the occasional snapshot with it, then maybe it's acceptable. But it is a lossy method. How much is lost, I don't know. Simple distortion correction does eat up a little resolution too, but it's an acceptable amount of loss.
    9. As an APS-C shooter, the 17-170mm 3.5 would be so nice to have

      Is it giving us that much more over the 18-135mm f/3.5-5.6 is stm or 55-250mm f/4-5.6 is stm? The constant aperture is nice, no question. It is two stops brighter on the long end. I could definitely see myself getting one. But... are we really hurting on the general purpose travel/telephoto end?

      We'd be better off with a refresh of the 17-55mm f2.8 with improved IQ, five stops of IS, and get it down to f1.8 to really breathe new life into EF-S/APS-C. Come on, Canon, the market wants it, your superb lens team can deliver it, JUST DO IT.
    10. As I recall the 24-240 has a LOT of distortion.

      So much that it would be unusable on an optical view finder, and Canon had to adjust camera firmware to do the adjustments for the EVF as well.
    11. As I recall the 24-240 has a LOT of distortion.

      So much that it would be unusable on an optical view finder, and Canon had to adjust camera firmware to do the adjustments for the EVF as well.
      yes, the magic of mirrorless ;)
    12. 28-240 f2.8 is a good sign that Canon is serious about a sports/action oriented R. Of course such a lens would be crazy expensive, but I can image it becoming the go-to lens for indoor sports shooters who can afford it.
    13. Is it possible that these kind of lenses are espcially meant for the combined EF/RF body with the presumably moving sensor? Would this make sense?

      Frank
    14. I'd be happy with an RF 24-105 f/2.8. Although that 28-280 sounds amazing, I have looked at the Sigma 120-300 f/2.8 S. Reasonably priced when a used copy comes on the market
    15. Is it possible that these kind of lenses are espcially meant for the combined EF/RF body with the presumably moving sensor? Would this make sense?

      Frank

      I would truly not get your hopes up for the rumored EF/RF body, yet.
    16. It feels wrong to have lenses that force you to use a crop on a FF body. But it seems to allow pushing the Canon lens lineup into unseen before territory... I don't know. Canon are supposed to be the kings of lens development, but it also seems like they are embracing the amount of compromise they can get away with on the R system a bit too much. Like how much vignetting there is and now this trend of having essentially straight up black corners in wide angle lenses...
    17. It feels wrong to have lenses that force you to use a crop on a FF body. But it seems to allow pushing the Canon lens lineup into unseen before territory... I don't know. Canon are supposed to be the kings of lens development, but it also seems like they are embracing the amount of compromise they can get away with on the R system a bit too much. Like how much vignetting there is and now this trend of having essentially straight up black corners in wide angle lenses...
      Check this out from photography life .com I happen to like vignetting myself. I often add it. The corners, to me, are not bad at all on a well lit subject. Outdoors it is barely visible. They are far from straight up black. I should add that I never take photos of just walls and backdrops... solid color or brick. I have seen tests that give the wide open vignetting anywhere from 3 to 4 stops. I personally think that 4 stops is a real stretch and how the backdrop was lit will contribute greatly as to the test results. In camera auto correction makes it a non-issue. Then the vignette is almost gone by f/1.6.
      7. Vignetting
      Ultra-wide aperture lenses usually produce heavy vignetting, and the RF 50mm f/1.2L USM exhibits around 3.3 stops of light falloff at f/1.2.
      RF 50mm Vignetting
      Canon EOS R + RF50mm F1.2 L USM @ 50mm, ISO 100, 1/8000, f/1.2
      Things improve at f/1.6, where vignetting is only about 2.2 stops, better than many wide-aperture lenses on the market. By f/2, vignetting is easily correctable (about 1.5 stops) – and it is a non-issue at f/2.8, totaling only one stop. Beyond that, the RF 50mm f/1.2 exhibits less than a stop of vignetting, which is negligible in real-world images.
      RF 50mm Vignetting 1
      Canon EOS R + RF50mm F1.2 L USM @ 50mm, ISO 100, 1/1600, f/2.8

      Then there's this: https://www.opticallimits.com/canon_eos_ff/1055-canonrf50f12?start=1
    18. Check this out from photography life .com I happen to like vignetting myself. I often add it. The corners, to me, are not bad at all on a well lit subject. Outdoors it is barely visible. They are far from straight up black.
      I like a bit of vignetting too. With straight up black I was referring to the 24-240mm which has an image circle that doesn't cover the entire sensor at the wide end. If you look at the image height of the patents, you'll see they also don't have a FF image circle at the wide end. Canon simply applies a profile which crops the image to effectively reduce the sensor size to something that is covered by the smaller wide angle image circle. I just don't feel good about that approach. But that's just my opinion, nothing that should matter to you. I'm not saying it is a bad move by Canon to investigate these new options!
    19. I like a bit of vignetting too. With straight up black I was referring to the 24-240mm which has an image circle that doesn't cover the entire sensor at the wide end. If you look at the image height of the patents, you'll see they also don't have a FF image circle at the wide end. Canon simply applies a profile which crops the image to effectively reduce the sensor size to something that is covered by the smaller wide angle image circle. I just don't feel good about that approach. But that's just my opinion, nothing that should matter to you. I'm not saying it is a bad move by Canon to investigate these new options!
      ;) I wasn't trying to step on your opinion, just what others have said in other tests and from my own personal experience. Since the lenses aren't even in production yet, I assumed you were talking about what has already been manufactured.:) Thank you for the clarification. I know nothing about the technical side and how Canon does what Canon does. I just take photos and judge the end result.

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