It looks like Tamron is going to be announcing a 17-50mm f/4 lens some time this year going by the latest optical formula patent to appear. This patent looks pretty in-depth and that's usually a sign of things to come.

This optical formula is for full-frame sensors and the lens also has an internal zoom design.

Patents don't tell us which mounts an optical formula is for, but for Canon shooters….. you know.

Tamron 17-50mm f/4 Optical Formula

  • Focal length: 17.52mm – 48.483mm
  • F-number: 4.120
  • Half angle of view: 110.747° – 47.366°
  • Height: 21.633mm
  • Length: 134.456mm
  • Back focus: 18.462mm – 50.815mm

This patent was uncovered and published by asobinet.

Some of our articles may include affiliate links. If you purchase through these links, we may earn an affiliate commission at no extra cost to you.

Go to discussion...

Share.

17 comments

  1. Isn\'t this a rather weird focal range for a FF lens? 17-50mm seems more like a typical APSC type normal zoom.
    The concept is probably that it’s a 17-35mm (or indeed Canon’s 17-40mm) ultrawide extended at the tele end. Rather useful to get all wide focal lengths in a single lens, really. Wouldn’t have been feasible on a SLR most likely.
  2. why is this being posted if its not for RF?
    While the patent doesn't include mount specific info, Tamron already has a 17-70 in constant 2.8 for Sony and Fuji. Nikon has a 16-50 in variable aperture, so it does make sense that this patent will likely be for RF mount. We all know both Tamron and Sigma are eager to get into the game. This is another indicator its coming.
  3. it does make sense that this patent will likely be for RF mount.

    It seems premature to me; but let's hope so, because means that Canon will open the RF mount
  4. why is this being posted if its not for RF?
    Because it can be adapted and there are lots of people still using DSLR cameras. There's a big wide world out there. I think users here are atypical.
  5. While the patent doesn't include mount specific info, Tamron already has a 17-70 in constant 2.8 for Sony and Fuji. Nikon has a 16-50 in variable aperture, so it does make sense that this patent will likely be for RF mount. We all know both Tamron and Sigma are eager to get into the game. This is another indicator its coming.
    Whether RF or EF, I believe, is dependent upon the back focus distance? So what is that for RF?
  6. This is quite a nice focal length range, as it means minimising the gap in focal length coverage for a 2-lens kit (17-50 plus 70-200 vs 14-35 plus 70-200). It is longer than even the RF 15-35mm F2.8. Hope it is not too heavy compared to the RF 14-35mm F4.
  7. I would love to have it in FF, but if is APS-C. Still decent enough.

    I strongly believe Canon won\'t bother making a f4 zoom for RF-S, might as well leave it to 3rd parties.
  8. Isn\'t this a rather weird focal range for a FF lens? 17-50mm seems more like a typical APSC type normal zoom.
    I had a Canon EF 17-40/4L for many years, was a great lens. An extra 10mm on the long end would have been very nice.
  9. Whether RF or EF, I believe, is dependent upon the back focus distance? So what is that for RF?
    I cannot imagine Tamron releasing any new SLR lenses today.
  10. Whether RF or EF, I believe, is dependent upon the back focus distance? So what is that for RF?
    The Canon EOS RF mount has a 20 millimetre Flange Focal Distance (FFD a.k.a. Back Focus) whereas the older EF mount had a 44 millimetre FFD.
  11. Because it can be adapted and there are lots of people still using DSLR cameras. There's a big wide world out there. I think users here are atypical.

    This is likely a mirrorless design lens; it cannot be adapted on any DSLR; it's DSLR lenses that can be adapted to mirrorless, but not the other way around.
    And I'm pretty sure Tamron (or Sigma, or Canon, or Nikon, or any of the main competitors) is not going to release any new DSLR lens in any possible future; Canon released its last DSLR lens in 2018, 5 years ago...you won't see another, from nobody, DSLR tech is dead tech for the brand new stuff.
  12. This is likely a mirrorless design lens; it cannot be adapted on any DSLR; it's DSLR lenses that can be adapted to mirrorless, but not the other way around.
    And I'm pretty sure Tamron (or Sigma, or Canon, or Nikon, or any of the main competitors) is not going to release any new DSLR lens in any possible future; Canon released its last DSLR lens in 2018, 5 years ago...you won't see another, from nobody, DSLR tech is dead tech for the brand new stuff.
    Yup. I know RF can't be adapted to EF. That's a given.
  13. It seems premature to me; but let's hope so, because means that Canon will open the RF mount

    I don't believe Canon "opens" mounts. It just enforces its intellectual property, particularly where it feels that another company's representation of 3rd party mount use would set a precedent limiting its future enforcement of its rights.

    The big hubbub months ago about "Canon" in Germany throwing a sue-ball at a third party manufacturer for representations about the RF mount seemed to me to be less a lens mount issue and more of a trademark issue. The third party was representing the lens as being an RF compatible lens. But RF means more than just fitting on those three flanges. RF connotes certain communications advantages, etc. My sense from the little coverage we saw in 2022 on the issue was that Canon caught them up on advertising representations. This was supported by it being a suit in Germany that didn't involve patents, but rather trade practices.

    There doesn't seem to be any legal issue with creating RF-fitting lenses, and there has never been an issue with using Canon's still-decent EF-mount-reverse-engineered autofocusing protocols, whether on RF or EF. I have a very fine 85mm f/1.4 third party RF lens that autofocuses great for portraits (not so much for sports). It cost me $450. I have the Canon EF 600mm f/4 III, and it focuses indistinguishably (for me at least) from the RF version.

    Sigma and Tamron are so far choosing not to put EF autofocusing on RF mount mirrorless lens designs, which is interesting. Sigma's CEO has indicated for years that he'd like to put out RF-mountable lenses. There is the theoretical ability for Canon to produce new cameras that goof up EF protocols, but I think that unlikely. There is the possibility that Canon is rope-a-doping the third parties by negotiating RF autofocus access starting at some point in the future. Perhaps the simplest explanation is that the supply chain issues have allowed the lens makers to focus their limited manufacturing capacity on the sure-thing mounts.

    Upshot: I think the camera forum consensus about the RF mount being closed is incorrect. More complicated, yes. Unexploited, certainly.
  14. While the patent doesn't include mount specific info, Tamron already has a 17-70 in constant 2.8 for Sony and Fuji. Nikon has a 16-50 in variable aperture, so it does make sense that this patent will likely be for RF mount. We all know both Tamron and Sigma are eager to get into the game. This is another indicator its coming.
    Those are both APS-C. This is FF, so a very different lens.
  15. Whether RF or EF, I believe, is dependent upon the back focus distance? So what is that for RF?
    Flange distance for RF is 20mm, but back focus can be less if the rear element protrudes behind the flange. From an optical physics perspective, this design should be applicable to any of the FF mirrorless mounts.

Leave a comment

Please log in to your forum account to comment