Here is a new Canon patent application: two super telephoto zooms for the RF mount.

Canon patent application 2023135180 (Japan, published 9/28/2023) discusses optical formulas for two super telephoto zoom lenses for the RF mount:

• 200-1000mm F5.6-11 IS
• 200-800mm F5.6-8 IS

From the patent literature:

To obtain a zoom lens whose entire system is compact and whose optical performance is suppressed from deteriorating due to focusing.

BACKGROUND ART

As an imaging optical system, a telephoto zoom lens having a long focal length at the telephoto end is known. (Patent Document 1) Such a zoom lens is required to be small, yet easy to perform high-speed focusing, and to suppress deterioration of optical performance due to focusing.

However, the zoom lens disclosed in Patent Document 1 has a large number of lenses in the fourth lens group, which is a focus group, and also has relatively strong refractive power. Therefore, it is difficult to simultaneously increase the speed of focusing and suppress deterioration in optical performance due to focusing.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a zoom lens whose entire system is small in size and whose optical performance is suppressed from deteriorating due to focusing, and an imaging device having the zoom lens.

Example 1

• Focal length: 206.00-778.20
• F value: 5.71-9.18
• Half angle of view: 6.00-1.59
• Image height: 21.64
• Total length: 330.11-420.11
• Back focus: 40.03-96.02

Example 2

• Focal length: 200.00-998.33
• F value: 5.71-11.00
• Half angle of view: 6.17-1.24
• Image height: 21.64
• Total length: 346.80-456.78
• Back focus: 43.85-105.49

Example 3

• Focal length: 206.00-775.95
• F value: 5.83-8.00
• Half angle of view: 6.00-1.60
• Image height: 21.64
• Total length: 330.08-420.12
• Back focus: 38.46-38.46

More Canon patents are listed here.

[via asobinet]