Canon Patent: Keep High-precision Autofocus During Tilt-shift Operations

Here is a new Canon patent application, another one that deals with tilt-shift lenses.

The Canon patent application, published on October 18, 2023, discusses methods and technology to make sure autofocus is kept during tilt-shift operations with the lens.

From the patent literature:

• An object of the present invention is to provide a control device that can maintain focus with high accuracy even when obtaining a tilt effect or a shift effect.
• Background Art
  Conventionally, a tilt effect that tilts the focusing surface and a shift effect that moves the shooting range have been used to achieve good overall focus on an object surface that is tilted with respect to the optical axis of an imaging optical system. A resulting optical system has been proposed. Patent Document 1 discloses an optical system that can obtain a tilt effect and a shift effect by moving two optical elements in a direction perpendicular to the optical axis.
• However, the optical system of Patent Document 1 does not take into account that the amount of defocus changes by moving the optical element in the direction perpendicular to the optical axis, so it does not take into account that the tilt effect or shift effect is applied after focusing. If the optical element is moved in a direction perpendicular to the optical axis in order to obtain an image, the focus will shift.
• An object of the present invention is to provide a control device that can maintain focus with high precision even when obtaining a tilt effect or a shift effect.

More Canon patents are listed here.

[via asobinet.com]