Canon Patent Application: Canon RF 70-300mm F4-5.6, 70-400mm F4-5.6

In this patent application, we have a Canon RF 70-300mm consumer zoom and what could be a replacement for the workhouse 100-400mm on the RF mount, a 70-400mm F4-5.6

This patent application could only be for the RF mount, since the backfocus instance at 70mm is 25mm which is far under the 44mm of the EF mount for the 70-300 and 13.8mm for the 70-400mm.

The 70-400mm F4-5.6 could certainly be the RF equivalent of the Canon EF 100-400mm 4.5-5.6L, with a slightly simpler design of only 18 elements down from 21 elements in the EF mount lens.

focal length   72.00   146.00   290.00
F number     4.08     4.88     5.67
Half angle of view (degrees)  16.72     8.43     4.27
Image height        21.64    21.64    21.64
Total lens length   140.00   177.20   210.00
BF            25.13    44.86    61.65

focal length 72.62 168.49 389.89
F number 4.07 5.10 5.85
Half angle of view (degrees) 16.59 7.32 3.18
Image height 21.64 21.64 21.64
Total lens length 187.91 236.14 268.26
BF 13.80 27.53 35.04

Also listed in the patent application is a consumer RF 70-200mm lens, which would be novel especially if Canon could keep the cost weight and size down considerably.

focal length 72.00 100.00 200.00
F number 4.12 4.45 5.88
Half angle of view (degrees) 16.72 12.21 6.17
Image height 21.64 21.64 21.64
Total lens length 140.00 149.14 160.00
BF 14.00 13.81 37.21

Japan Patent Application 2019-158961