Sigma's versatile APS-C standard zoom for Pentax — the 17-70mm f/2.8-4 with macro capability.
The Sigma 17-70mm f/2.8-4 DC Macro OS HSM Contemporary is a versatile APS-C standard zoom for Pentax K mount, covering a 25-105mm equivalent range with a fast f/2.8 starting aperture. The macro mode allows close focusing. The Contemporary designation indicates compact design with good optics. HSM motor provides quiet autofocus.
Optical performance is good for the class. Centre sharpness is very good at wider focal lengths. The f/2.8 starting aperture provides a brighter viewfinder and more DOF control than standard kit zooms. The macro mode allows closer-than-normal focusing for casual close-up work. OS stabilisation adds handheld shooting confidence in lower light.
Pentax K mount, APS-C. Filter thread is 72mm. Weight is approximately 470 grams — moderate. Build quality is good with the Contemporary designation. HSM motor is quieter than Pentax's body-driven screw-drive AF. OS stabilisation supplements Pentax's in-body SR. The 25-105mm equivalent range covers the vast majority of everyday shooting situations.
Available on the used market at reasonable prices. Check OS motor, AF accuracy, and smooth zoom. An excellent everyday zoom for Pentax APS-C shooters — the fast starting aperture and macro mode add genuine versatility over kit zooms. Benefits from both OS and Pentax body SR for excellent stabilisation.