The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon EF 50mm f/1.8 STM and the Sigma 17-70mm F2.8-4 DC OS HSM C 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 17-70mm F2.8-4 DC OS HSM C is the longer of the two lenses at 82mm. The Canon EF 50mm f/1.8 STM with a length of 39mm, is 43mm shorter. Besides being longer, the Sigma 17-70mm F2.8-4 DC OS HSM C also has a larger diameter of 79mm compared to the Canon EF 50mm f/1.8 STM's 69mm 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. Canon EF 50mm f/1.8 STM weighs 159g, which means it is 306g (65%) lighter than the Sigma 17-70mm F2.8-4 DC OS HSM C which has a weight of 465g.
Filter Threads
The Canon EF 50mm f/1.8 STM has a filter size of 49mm whereas the Sigma 17-70mm F2.8-4 DC OS HSM C has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Canon EF 50mm f/1.8 STM:
And these are the 72mm filters that we recommend for the Sigma 17-70mm F2.8-4 DC OS HSM C:
Lens Mounts
Both the Canon EF 50mm f/1.8 STM and the Sigma 17-70mm F2.8-4 DC OS HSM C has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Sigma 17-70mm F2.8-4 DC OS HSM C is also available in Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Canon EF 50mm f/1.8 STM is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
80mm.
On the other hand, the Sigma 17-70mm F2.8-4 DC OS HSM C 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.
