Bonkers-Class Sigma 35mm f/1.2 Balks at AF-C; But Only on Camera It Was Designed For

Sep 4, 2020 | Lenses, News, Sigma

Camnostic staff own and love Sigma lenses, and especially the bonkers-class ones that Sigma invents that previously were thought to have been impossible or unlikely – like the f/1.2 35mm Art lens that Sigma released a year ago targeting the A7R IV camera. But Sigma yesterday announced today that they were confirming reports that the lens is failing to autofocus when shot at f/1.2 in continuous autofocus mode on the A7R III and the A7R IV.

This is a lens owned by a Camnostic contributor, and we can confirm that it is at least not a consistent problem, as we cannot here replicate this misbehavior on the A7R IV, with the most recent firmware in both the camera and lens. Sigma reports the problem is limited to specific shooting distances, but we could see no case where the lens didn’t rack focus. Readers are encouraged to write in to indicate if they can replicate the problem – and especially at what focal lengths the problem might present itself.

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