Canon Patent Application: Canon RF 19mm F2.8 IS

This is a curious patent application from Canon.  At the heart of it, is two embodiments that are rather interesting, which describe a 19mm F2.8 with image stabilization.   This patent is about providing image stabilization for shorter lenses, so there are a few other examples given in this patent application. 

Canon RF 19mm F2.8 IS

​Focal length          19.50  
F number               2.88  
Half angle (degree)   47.99  
Image height          21.65  
Lens total length     96.33  
BF                    18.34

Canon RF 19mm F2.8 IS

Focal distance        19.29  
F number               2.86  
Half angle (degree)   48.30  
Image height          21.65  
Lens total length     96.59  
BF                    18.43  

There are also other embodiments that we will probably never see such as this one for an 85mm F1.8, but since we already have the 85mm F2.0, this will probably never come.

Focal length          82.88  
F number               1.86  
Half angle (degree)   14.63  
Image height          21.64  
Lens total length    107.79  
BF                    23.52 

This embodiment with its ultra short back focus is probably an example of an EOS-M zoom lens since it's also APS-C;

Focal length         10.83  13.48  20.68    
F number              4.10   4.52   5.72    
Half angle (degrees) 51.59  45.38  33.44     
Image height         13.66  13.66  13.66     
Lens total length    89.25  86.77  88.08     
BF                    9.86  13.52  23.58   

Japan Patent Applicaton  2021-067826