A patent showcasing a host of optical formulas from Canon has appeared over at Canon News. These patents deal with small focusing groups that allow for light and fast autofocus performance, perhaps more geared to STM than to USM motors being used.
Optical Formulas Covered in the Patent:
- 11-22mm f/4-5.6
- 24-70mm f/2.8
- 35mm f/2.8
- 18-150mm f/3.5-6.3
We’re not sure if these are EF, EF-S, or EF-M lenses, or a mixture of all three mounts.