Sigma patent application for 24, 35 and 40mm primes for the L-mount
This patent application has a variety of mirrorless full frame primes by Sigma.
- 35mm F1.8
- 35mm F2.0
- 40mm F1.8
- 24mm F1.8
- 35mm F1.4
These lenses are designed specifically to assist with the prevention of "wobbling" as a lens AF's using contrast AF. These look and appear to be designed specifically tuned to Panasonic's DFD implementation and their contrast AF.
From the patent application;
The present invention is most suitable for digital cameras, silver halide cameras, video cameras, and the like. In particular, the field angle is about 62 ° to 98 ° and the back focus is short. The present invention relates to an imaging optical system optimal for a mirrorless camera. As one of the in-focus method of mirror-less camera, there is a contrast AF. In contrast AF, focus position detection is performed by driving the focus lens by wobbling. The wobbling drive is to move the focus group minutely at high speed in the optical axis direction in order to detect the in-focus direction. If the fluctuation of the image magnification during wobbling is large, the size of the subject changes on the screen, so that the quality of the image is remarkably deteriorated particularly during moving images. Therefore, it is necessary to reduce the image magnification fluctuation during wobbling.
Japan Patent Application 2019-191229
This post may contain affiliate links(s). An affiliate link means I may earn advertising/referral fees if you make a purchase through my link, without any additional cost to you
. It helps to keep this site afloat. Thank you in advance for your support. If you like what we do here, maybe buy me a coffee.