Sigma 12-24mm F4.5-5.6 EX DG HSM is an Auto Focus (AF) Wideangle Zoom
lens with 35mm FF max sensor coverage and it is designed to be used with Pentax KAF mount cameras.
Sigma 12-24mm F4.5-5.6 EX DG HSM is compatible with cameras that have Pentax KAF lens mount.Some of the latest released cameras with Pentax KAF lens mount are Pentax K-3 III
, Pentax K-1 II
and Pentax KP
Max sensor coverage of Sigma 12-24mm F4.5-5.6 EX DG HSM is 35mm FF.
Sigma 12-24mm F4.5-5.6 EX DG HSM has a focal range of 12-24mm and 2.0X zoom ratio. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 18 - 36mm.
Optical Image Stabilization
Sigma 12-24mm F4.5-5.6 EX DG HSM doesn't have an optical image stabilization system so the only option to stabilize the image taken with this lens is to mount on a camera body with IBIS (sensor based In-body image stabilization).
Sigma 12-24mm F4.5-5.6 EX DG HSM features Rotary (internal) zoom method where the length of the lens doesn't change while you are zooming in or out. Even though this design has a size disadvantage in general compare to extending designs, it has the benefits of better sealing against dust and moisture, no zoom creep and no weight balance shift while zooming.
Sigma 12-24mm F4.5-5.6 EX DG HSM is a variable aperture lens with a max aperture of f4.5 and a minimum aperture of f22 at 12mm, and a max aperture of f5.6 and minimum aperture of f22 at 24mm .
Sigma 12-24mm F4.5-5.6 EX DG HSM's optical formula consists of 16 elements in 12 groups.