Here are some newly spotted wide-angle Sigma zoom lens patents that are f/1.8. The Sigma 15-24mm f/1.8, 16-28mm f/1.8, and 18-30mm f/1.8 could all be useful zooms, but they will likely be very expensive given their fast apeture.
- Applicant: Sigma Co., Ltd.
Publication number: P2022126058
Application number: P 2021023909
Publication date: 2022-08-30Title
of invention: Zoom lens
- A large aperture wide-angle zoom lens capable of high-speed AF control, suppressing aberration fluctuations during focusing, and compatible with a large format camera is provided with a compact optical system.
- The zoom lens described in Patent Document 1 achieves weight reduction of the focus group. However, it is difficult to apply to a large-aperture zoom lens because of its dark open F-number and insufficient correction of various aberrations such as longitudinal chromatic aberration and curvature of field.
- The zoom lens described in Patent Document 2 achieves weight reduction of the focus group and improves longitudinal chromatic aberration and curvature of field as compared with Patent Document 1. However, since the total length of the optical system is long, it is not realistic to make the optical system extremely large if it is to be used with a large-aperture camera or a large-format camera with a large maximum image height.
- According to the present invention, the optical system is made compact by shortening the overall length and reducing the outer diameter. The focus lens group is light, and high-speed AF control is possible. It is possible to provide a large-aperture, wide-angle zoom lens that can be used with any camera and has high optical performance.