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Canon Patent: RF 100-300mm F2.8 x 1.4 Extender Lens

Canon Patent

A new Canon patent application for another RF mount lens. Canon patent application 2023018429 (Japan, published 2/8/2023) discusses optical formulas for an RF 100-300mm F2.8 x 1.4 extender lens.

From the patent literature:

A zoom lens having a large aperture and a long focal length is provided, in which the focal length range can be easily changed to the long focal length side by an extender, and good optical performance can be maintained even before and after the extender is inserted.

A known method is to change the focal length of the optical system by inserting an extender (magnification conversion group) separate from the main optical system.

However, since a large air gap is required to insert the extender into the optical path, if the position for inserting the extender is inappropriate, the size of the main optical system and the extender will increase. Also, in order to maintain good optical performance before and after inserting the extender, it is necessary to appropriately set the refractive powers of the lens groups before and after the extender.

In the present invention, by inserting an extender into the main optical system, the focal length range can be easily changed to the long focal length side. The purpose is to provide a long zoom lens.

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

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