The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 18-50mm F2.8-4.5 DC OS HSM and the Canon 50mm f1.8 II 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 18-50mm F2.8-4.5 DC OS HSM is the longer of the two lenses at 89mm. The Canon 50mm f1.8 II with a length of 41mm, is 48mm shorter. Besides being longer, the Sigma 18-50mm F2.8-4.5 DC OS HSM also has a larger diameter of 74mm compared to the Canon 50mm f1.8 II's 68mm 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 50mm f1.8 II weighs 130g, 67% (265g) lighter than the Sigma 18-50mm F2.8-4.5 DC OS HSM's weight of 395g.
Filter Threads
The Sigma 18-50mm F2.8-4.5 DC OS HSM has a filter size of 67mm whereas the Canon 50mm f1.8 II has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Sigma 18-50mm F2.8-4.5 DC OS HSM:
And these are the 52mm filters that we recommend for the Canon 50mm f1.8 II:
Lens Mounts
Both the Sigma 18-50mm F2.8-4.5 DC OS HSM and the Canon 50mm f1.8 II has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Sigma 18-50mm F2.8-4.5 DC OS HSM is also available in the Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Sigma 18-50mm F2.8-4.5 DC OS HSM has a focal range of 18-50mm and
2.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
28.8-80mm when used on a APS-C / DX format camera.
On the other hand, the Canon 50mm f1.8 II 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.
