Canon Patent Application: 18-45mm APS-C but NOT for RF mount
A patent application appeared off schedule for Canon, showing an APS-C lens. I didn't initially report on this because well, the lens is really nothing. But since a few other sites picked it up and ran with it, I guess I had to then. Some sites have claimed this is an RF lens. It's extremely unlikely.
As far as this application; The lens is trash with a stretched image circle at even 18mm. It's also very large with a lens length of around 72mm. The back focus distance is around 30mm to 50mm from wide to telephoto.
Canon doesn't need to do any patent applications for RF APS-C. All of the EF-M lenses are easily movable to the RF mount. In a kit lens case, Canon already has a working 15-45 and an 18-55mm. There's no way Canon is going to use a back focus distance of 30mm on a mirrorless RF APS-C Lens. The lens length of 72mm is also too large for a mirrorless APS-C lens of 45mm on the telephoto end. Even the 18-55mm EOS-M would be 59mm and it's longer, and faster than these embodiments.
If we're going to find patent applications for RF APS-C it will be something like a 15-45mm F2.8, or a 17-55mm F2.8, or perhaps a 15-200mm super zoom. It's not going to be an 18-45mm kit lens, which is a poor range by today's standards.
What would this lens be for? Quite possibly it's simply a patent application of an older design, from EF-S days. Canon does patent things they probably never will ever use. However, it's really the optical formulae they are applying for a patent on. In this case, the embodiments simply aren't mirrorless.
I get that we all want to find the smoking gun that shows that Canon is making RF APS-C lenses, but in reality, they already have all they need. We'll have to wait a little while longer to find a lens that uniquely appears to be an RF APS-C lens - assuming Canon is even going to make a special one specifically for the RF system.
Canon 18-45mm F4.5 - 6.5
focal length 18.53 30.00 43.65
F number 4.54 5.43 6.50
Half angle (°) 33.78 24.48 17.38
Image height 12.40 13.66 13.66
Total length of lens 92.00 81.80 83.05
BF 30.20 39.83 51.20
Canon 18-45mm F4.5 - 6.5
focal length 18.53 30.00 43.65
F-number 4.56 5.48 6.50
half angle (°) 33.78 24.48 17.38
Image height 12.40 13.66 13.66
total lens length 89.11 81.23 81.40
BF 28.48 38.21 47.77
Japan Patent Application JP2021-162822
3203
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