A new Canon patent application was spotted.
Canon patent application 2023099388 (Japan, published 7/13/2023) discusses optical formulas for what appears to be an RF 100-300mm f/2.8L IS USM lens for the EOS R camera system. From the patent literature:
Title of Invention
A zoom lens, an imaging device having the same, and an imaging system.
An object of the present invention is to provide a lightweight zoom lens that has high optical performance over the entire zoom range, and an imaging device and an imaging system having the zoom lens.
Description of the Related Art
In recent years, zoom lenses used in imaging apparatuses are required to have high optical performance over the entire zoom range and to be lightweight. In order to meet these requirements, the zoom lens has a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group including a plurality of lens groups, arranged in order from the object side to the image side. Lenses have been proposed (see Patent Documents 1 and 2).
A large-aperture telephoto zoom lens having a long focal length and a small F-number tends to have a large lens diameter, which tends to cause an increase in weight. In order to reduce the weight of the zoom lens, it is effective to increase the positive refractive power of the first lens group and reduce the lens diameters of the lens groups included in the subsequent group. However, if the refractive power of the first lens group is made too strong, it becomes difficult to correct spherical aberration, axial chromatic aberration, and lateral chromatic aberration, especially at the telephoto end.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lightweight zoom lens that has high optical performance over the entire zoom range, and an imaging apparatus and imaging system having the zoom lens. Focusing is performed by moving the fifth lens unit L5 and the sixth lens unit L6 along different trajectories . Specifically, the fifth lens unit L5 and the sixth lens unit L6 move toward the image side when focusing from an infinite object to a close object.
Example 1
- Focal length: 103.00-292.00
- F-value: 2.90
- Half angle of view: 11.86-4.24
- Image height: 21.64
- Total length: 333.61
- Back focus: 31.93
More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:
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