Tag Archives: Tamron 20-72mm F4

Sigma 135mm f/1.8 DG DN and Tamron 16-70mm f/4, 20-72mm f/4, 28-72mm f/4 Patents Found

Sigma 135mm f/1.8 DG DN [Publication Number] Japanese Patent Application Laid-Open No. 2021-85935 (P2021-85935A) [Publication date] June 3, 2021 [Application date] November 26, 2019 [Applicant] [Identification number] 000131326 [Name or name] Sigma Co., Ltd. PROBLEM TO BE SOLVED: To provide an optical system which achieves miniaturization and weight reduction while correcting various aberrations such as […]

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