Canon Patent Application: Super Telephoto primes

When Canon released the 400, and 600 III telephotos last September, the claim was a further weight reduction and a better balance. These patent applications show how Canon is moving the elements to the back of the lens, leaving one large element furthermost away from the lens mount.

Focal distance 294.00 
F number 2.91 
a half field angle (degree) -- 4.21
image height 21.64 
Whole length of the lens 276.40 
BF 65.35 

Focal distance 392.00 
F number 2.90 
a half field angle (degree) -- 3.16 
Image height 21.64 
Whole length of the lens 371.25 
BF 69.92

Focal distance 490.00 
F number 4.12 
a half field angle (degree) -- 2.53 
Image height 21.64 
Whole length of the lens 410.77 
BF 66.03

Focal distance 588.00 
F number 4.12 
a half field angle (degree) -- 2.11 
Image height 21.64 
Whole length of the lens 474.78 
BF 80.59

Focal distance 784.00 
F number 5.80 
a half field angle (degree) -- 1.58 
Image height 21.64 
Whole length of the lens 484.53 
BF 75.94

Japan Patent Application: 2019032390 and 2019032391