Canon has filed a patent application for a new ‘Moon shooting mode’ which appears to be in development for mirrorless or Powershot cameras.
The patent application suggests the new moon shooting mode would switch to contrast AF instead of using phase detect AF. US Patent Application 20490158760 says:
In recent years, the number of pixels in image capturing apparatuses such as cameras and videos has increased, a slight defocus state of an image has become conspicuous and, more precise focusing is desired. This is the same in shooting an image of celestial bodies (stars, moon, and so forth) in the night sky.
Focusing on celestial bodies is performed by calculating a focus position at which an area represented by high brightness signals is strictly minimized when regarding each celestial body as a point light source. As stars and the moon which are subjects in astrophotography at night are located substantially at infinity and there are specific exposure settings for astrophotography, there is an independent shooting mode for astrophotography different from other scene modes. Hereinafter, a mode for shooting the moon as the main subject is referred to as a “moon shooting mode”.
Normally, the focus position at which an object located substantially at infinity is in focus is uniquely determined by performing infinite focus adjustment in individual image capturing apparatus. However, due to a difference between temperature at a time of the infinite focus adjustment and temperature of the image capturing apparatus at a time of actually shooting a celestial body, a difference in posture, and so forth, the focus may shift during shooting. For this reason, it is necessary to often adjust focus even during shooting a celestial body whose distance from the image capturing apparatus does not substantially change during shooting.
The news follows similar documents spotted earlier this year, which suggest Canon is also developing a Quad Pixel AF system to replace its Dual Pixel AF.
Via Canon News