Canon Patents

Patent: Full frame f/2 zoom, possibly for mirrorless?

A patent application showing an unusual f/2 zoom from Canon has appeared in Japan (Patent application: 2018-132675). It’s possible that this zoom lens is related to a  mirrorless camera body with its short BF distance.

Canon News tells us that the patent itself deals with a floating focus system to help reduce the size of the lens.

Japan patent application 2018-132675:

Focal distance      90.00 125.01 145.99 109.96 130.49
F number             2.06   2.06   2.06   2.06   2.06
a half field angle  13.52   9.82   8.43  11.13   9.41
Image height        21.64  21.64  21.64  21.64  21.64
Whole length       242.35 242.35 242.35 242.35 242.35
BF                  16.70 1 6.70  16.70  16.70  16.70 

Focal distance      72.03 115.04 145.99  92.39 123.70
F number             2.06   2.06   2.06   2.06   2.06
a half field angle  16.72  10.65   8.43  13.18   9.92
Image height        21.64  21.64  21.64  21.64  21.64
Whole length       217.72 217.72 217.72 217.72 217.72
BF                  22.47 2 2.47  22.47  22.47  22.47 

Focal distance      72.00 114.84 146.00  92.60 123.41
F number             2.06   2.06   2.06   2.06   2.06
a half field angle  16.72  10.67   8.43  13.15   9.94
Image height        21.64   21.64  21.64 21.64  21.64
Whole length       210.32 210.32 210.32 210.32 210.32
BF                  21.80  21.80 21.80   21.80  21.80 

The optical formulas show a very short zoom range, but being an f/2 lens, that would make some sense.

Optical formulas in the application:

  • 90-130mm f/2
  • 70-125mm f/2
  • 70-125mm f/2 (shorter backfocus)
Nov 2, 2016
240
66
#4
Boy, that’s a lot of elements.

Now that Nikon has announced, they’re being criticized for the new Z mount lens selection. It would be nice if this (these?) lens(es) would be announced at the same time as Canon’s New cameras.
 

RGF

How you relate to the issue, is the issue.
Jul 13, 2012
2,803
30
#5
very narrow zoom range. Does not interest me, but perhaps this is a technical demonstration, not a real product?
 
Aug 19, 2018
51
42
#6
This would seem to be a portrait zoom.
Most definitely. And I would think it would be an ideal portrait zoom - essentially consolidating the 85mm F/1.8 USM, 100mm F/2 USM, and 135mm F/2L USM into one lens. For the 90-130mm F/2 at least. But the 70-125mm is an interesting focal length as well.
 
Jun 6, 2011
143
2
#8
This is likely just a technical demonstration to illustrate the floating focus mechanism, perhaps chosen because it shows a large size-reduction in the lens i.e. they've chosen a focal range and aperture that most clearly shows the size-reduction benefits of floating focus.

Then again, why make things complicated with all those elements if it's just a paper exercise so maybe this is a lens that's being developed. As others have pointed out, it's perfect for portraits (though maybe I'd like it to be a little longer but that could just be because I've got a large, unflattering nose)
 

Daner

I'm New Here
Aug 15, 2017
14
8
Stockholm
#10
I have been tempted by Sigma's 50-100 f1.8 for my 7D Mk. II, but I haven't been convinced. An EF 70-140 f2 from Canon would be more likely to convince me.