Sigma 300mm f/2.8 DG DN, Sigma 200mm f/1.8, and Sigma 250mm f/2 Patents Found

By Louis Ferreira | Published: October 15, 2020

Sigma as a 300mm f/2.8 DG DN coming that will support ta 1.4x TC. You can read about the patent below.

[Publication number: publication number]
Japanese Patent Application Laid-Open No. 2020-170066 (P2020-170066A)
[Release date release date
October 15, 2020 oct 15 2020
[Name of the Invention]
Rear conversion lens
[Application date]
April 2, 2019 Apr 2 2019
[Applicant applicant]
[Identification number] 000131326
[Name or name]
Sigma Corporation
PROBLEM TO
BE SOLVED: To provide a rear conversion lens having a short flange back, corresponding to a mirrorless camera system having a large image pickup element, and having a small size and high imaging performance.
Compact rear conversion lens with high imaging performance for mirrorless camera systems with a short flange back and large image sensor.

Example 1 Example 1

There were also Sigma 200mm f/1.8 and Sigma 250mm f/2 patents found and the 250mm f/2 can act as a 500mm f/4 with a 2xTC.

[Publication number] Japanese Patent Application Laid-Open No. 2020-160100 (P2020-160100A)
[Publication date] October 1, 2020
[Title of Invention] Imaging Optical System
[Application date] March 25, 2019
[Applicant]
[Identification number] 000131326
[Name or name] Sigma Co., Ltd.
PROBLEM TO BE SOLVED: To provide an imaging optical system which can be used as a large-diameter telephoto lens in which various aberrations are satisfactorily corrected while achieving small size and light weight.

via asobinet 1, 2