The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 70mm F2.8 EX DG Macro and the Sigma 17-70mm F2.8-4 DC OS HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sigma 70mm F2.8 EX DG Macro is the longer of the two lenses at 95mm. The Sigma 17-70mm F2.8-4 DC OS HSM with a length of 89mm, is 6mm shorter. On the other hand, the Sigma 17-70mm F2.8-4 DC OS HSM has a larger diameter of 79mm compared to the Sigma 70mm F2.8 EX DG Macro's 76mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sigma 17-70mm F2.8-4 DC OS HSM weighs 520g, 1% (7g) lighter than the Sigma 70mm F2.8 EX DG Macro's weight of 527g.
Lens Mounts
The Sigma 70mm F2.8 EX DG Macro has the Pentax KAF lens mount whereas the Sigma 17-70mm F2.8-4 DC OS HSM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount and Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount.
Sigma 70mm F2.8 EX DG Macro is also available in the Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Sigma 17-70mm F2.8-4 DC OS HSM is also available in Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sigma 70mm F2.8 EX DG Macro is a prime lens with fixed focal lenght of 70mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105mm.
On the other hand, the Sigma 17-70mm F2.8-4 DC OS HSM has a focal range of 17-70mm and 4.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27.2-112mm when used on a APS-C / DX format camera.
