There will obviously be more RF-S lenses coming coming this year as well as next year. Today we see a patent for a couple of RF-S optical formulas. One of these optical formulas will likely be close to a future product by the looks of the designs.

The concept here seems to be a combination of the EF-S 17-55 f/2.8 USM and the EF-S 15-85 f/3.5-5.6 IS USM. We could see the RF-S 15-85mm f/2.8-4 IS USM being the likeliest product to come from these optical formulas.

Canon RF-S 15-70mm f/4

  • Focal length:15.45-67.94
  • F-number: 4.12
  • Half angle of view: 41.27-10.60
  • Height: 12.66-13.66
  • Overall length: 100.14-120.23
  • Back Focus: 10.46-12.37
RF S15 70mm F4 patent 728x810 - Patent: Canon RF-S 15-70mm f/4 and RF-S 15-85mm f/2.8-4
Source: https://asobinet.com/info-patent-rf-s15-85mmf2-8-4/

Canon RF-S 15-70mm f/2.8-4

  • Focal length:15.45-68.04
  • F-number: 2.8-4.12
  • Half angle of view: 41.38-10.61
  • Height: 12.66-13.66
  • Overall length: 100.32-118.71
  • Back Focus: 10.62-15.59
RF S15 70mm F2.8 4 patent 728x794 - Patent: Canon RF-S 15-70mm f/4 and RF-S 15-85mm f/2.8-4

Canon RF-S 15-85mm f/2.8-4

  • Focal length:15.45-83.77
  • F-number: 2.88-5.80
  • Half angle of view: 41.36-8.71
  • Height: 12.66-13.66
  • Overall length: 101.54-133.85
  • Back Focus: 12.12-16.91
RF S15 85mm F2.8 4 patent 728x797 - Patent: Canon RF-S 15-70mm f/4 and RF-S 15-85mm f/2.8-4
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52 comments

  1. Whilst not the greatest optic, the old 15-85 is my go to everyday lens on my 7DII, when not using my varying L lenses. Am considering changing one of my bodies to the R7 and a new up to date 15-85 would again be very useful.
  2. It would be really nice if it actually was a RF-S 15-85mm f/2.8-4 lens design, but as far as I can see from machine-translated original source it is a RF-S 15-85mm f/2.8-5.6 design.
    Still my favourite of the listed though, and would probably replace the EF-S 15-85mm on my R7.
  3. It would be nice if it really was a RF-S 15-85mm f/2.8-4 lens, but as far as I can see from machine-translated original source it is a RF-S 15-85mm f/2.8-5.6 design.
    You are quite correct.
    Good eye.
    RF-S 15-85mm f/2.8-5.6 makes far more sense to me than RF-S 15-85mm f/2.8-4.
  4. Cool. How do you find that?

    (PS. People reading comments directly from article can't see attached. Open comment thread in forum to see it: https://www.canonrumors.com/forum/t...s-15-70mm-f-4-and-rf-s-15-85mm-f-2-8-4.42290/)
    US Patent and patent applications can be browsed with the online tool provided by the USPTO (https://ppubs.uspto.gov/pubwebapp/). It works with Chrome but it doesn't work with Safari. I don't know if it works with other browsers.

    To search for all Canon patents and patent applications, type for example canon.aanm. in the input field on the upper left of the tool (the "." at the end is important). There might be better search terms if you are looking for lenses specifically, as the above will give you all patents filed by Canon. On the other hand, you also see filings about accessories, autofocus, IBIS, mechanical construction of camera bodies,... which can also be interesting. Patent applications are published on Thursdays.

    The leftmost button above the viewer switches to a pdf-like view, the document can be saved with the print button next to it.

    Note that the tool might block you if you browse through a large number of filings (at least it seems to do so in my case) by showing an "image not yet available" message. Usually after waiting a couple of minutes and reloading the tool you should be able to continue searching.

    I wasn't aware that attachments are not displayed, is there a better way to upload them?
  5. I got quite excited when I glanced at the headline. Then I realised these were crop lenses. :cry:

    A full frame 15-70mm would have been something to really get excited about!

    Nice options for the R7 though, so hopefully these will make it to production in the near future.
  6. RF-S 15-85mm f/2.8-5.6 makes far more sense to me than RF-S 15-85mm f/2.8-4.
    The 15-85mm seems most likely (but who knows, they went with 18-45mm for the kit lens).

    Not to rain on the parade, but the RF 100-500 patents topped out at f/6.3, and the RF 100-400 patent was f/5-7.1. The actual lenses are slower. I suspect if we see an RF-S 15-85, it will be f/3.5-6.3 (or 7.1).

    I also think it will be a cold day in Hades before we see a constant f/4 zoom for RF-S.
  7. The 15-85mm seems most likely (but who knows, they went with 18-45mm for the kit lens).
    The kit lens is likely for "content creators" (i.e. vloggers), while this one is for photographers.
  8. The kit lens is likely for "content creators" (i.e. vloggers), while this one is for photographers.
    Back in the day, we just had photographers (stills), videographers (movie makers) and vloggers (narcissists and influencers).

    Now we have "content creators", probably the most meaningless description of all time. Uggghhh!
  9. The kit lens is likely for "content creators" (i.e. vloggers), while this one is for photographers.
    Why would an 18-45mm lens be better for "content creators" than a 15-45mm lens or an 18-55mm lens? Seems more like Canon chose the cheapest option to produce to maximize their profit (and perhaps to spur purchases of lenses like the 16/2.8 and 15-30).
  10. Back in the day, we just had photographers (stills), videographers (movie makers) and vloggers (narcissists and influencers).

    Now we have "content creators", probably the most meaningless description of all time. Uggghhh!
    "Content Creator" seems to be a term for someone who uploads contend to a social media platform.
  11. Why would an 18-45mm lens be better for "content creators" than a 15-45mm lens or an 18-55mm lens? Seems more like Canon chose the cheapest option to produce to maximize their profit (and perhaps to spur purchases of lenses like the 16/2.8 and 15-30).
    I'd guess that the majority of "content creators" are novices trying their hand at vlogging (oops, I mean *creating*), and unlikely to want to spend much until they've gained experience. So yes, Canon will give them the cheapest option, and they'll be unlikely, as novices, to recognise the better quality that a more expensive lens would provide. Also of course, Canon want to be price-competitive with Sony.
  12. These are pretty interesting lenses! I wish more APS-C zooms would account for a 24mm field of view, as opposed to 27/28/29mm like Canon’s RF-S 18-45. I believe a similar patent existed for the EF-M mount that never saw the light of day. Hopefully this one hits the market.
  13. Why would an 18-45mm lens be better for "content creators" than a 15-45mm lens or an 18-55mm lens?
    1. Cheaper;
    2. More lightweight (and better balanced for reverse handholding and/or for use on small gimbals);
    3. More forgiving zoom range when shooting videos unprepared.
  14. 1. Cheaper;
    2. More lightweight (and better balanced for reverse handholding and/or for use on small gimbals);
    3. More forgiving zoom range when shooting videos unprepared.
    1. The RF-S 18-45 adds $120 to the R50 price, the EF-M 15-45 adds $100 to the M50 II kit price and the EF-S 18-55 adds $100 to the SL-3 price. So...no.

    2. The EF-M 15-45 weighs exactly the same 130g as the RF-S 18-45. The EF-S 18-55 was heavier, of course, but not a good comparator given the flange difference. The RF-S 18-150 is 10g heavier than the EF-M 18-150 (a difference of 3%). So...no.

    3. If someone starts 'creating content' without checking something obvious as framing of the image, the content is likely to be crap anyway. So...no.

    The only benefit of the more restricted zoom range is to Canon's bottom line. They're charging more for a less capable kit lens, and that means more profit. It's a perfectly reasonable choice from their perspective, but can you honestly say it benefits anyone buying the lens?
  15. 1. The RF-S 18-45 adds $120 to the R50 price, the EF-M 15-45 adds $100 to the M50 II kit price and the EF-S 18-55 adds $100 to the SL-3 price. So...no.

    2. The EF-M 15-45 weighs exactly the same 130g as the RF-S 18-45. The EF-S 18-55 was heavier, of course, but not a good comparator given the flange difference. The RF-S 18-150 is 10g heavier than the EF-M 18-150 (a difference of 3%). So...no.
    Are you trying to argue that the EF-M mount is smaller, cheaper (at the moment) and more lightweight solution than the RF-S mount?

    I don't think that anyone would object to that, but that's not the point.

    3. If someone starts 'creating content' without checking something obvious as framing of the image, the content is likely to be crap anyway. So...no.
    Looks like non sequitur.

    Hardly anyone expects them to create award-winning content with Canon's kit lenses. Still, their crappy content will look better to them if they don't (accidentially, but highly likely) use 24mm for selfie videos.

    The only benefit of the more restricted zoom range is to Canon's bottom line. They're charging more for a less capable kit lens, and that means more profit. It's a perfectly reasonable choice from their perspective, but can you honestly say it benefits anyone buying the lens?
    I'd say it's the same as with the lack of the filter rotation wondow on the hood of the RF 100-300L. It's not the solution I would personally prefer, but I'm not the target audience of this lens.

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