The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 18-300 F3.5-6.3 DC OS HSM and the Canon 35-350mm f3.5-5.6L USM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Canon 35-350mm f3.5-5.6L USM is the longer of the two lenses at 167mm. The Sigma 18-300 F3.5-6.3 DC OS HSM with a length of 102mm is 65mm shorter. Besides being longer, the Canon 35-350mm f3.5-5.6L USM also has a larger diameter of 85mm compared to Sigma 18-300 F3.5-6.3 DC OS HSM's 79mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Sigma 18-300 F3.5-6.3 DC OS HSM weighs 585g, which means it is 800g (57%) lighter than the Canon 35-350mm f3.5-5.6L USM which has a weight of 1385g.
Below you can find the dimension and weight table of the 'SuperZoom Lenses in Canon EF Mount for size comparison purposes.
SuperZoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Sigma 18-300 F3.5-6.3 DC OS HSM and Canon 35-350mm f3.5-5.6L USM 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 18-300 F3.5-6.3 DC OS HSM is also available in Nikon F (DX) , Pentax KAF3, Sigma SA and Sony Alpha mounts.
Focal Range
Sigma 18-300 F3.5-6.3 DC OS HSM has a focal range of 18-300mm and 16.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 28.8-480mm when used on a APS-C / DX format camera. Canon 35-350mm f3.5-5.6L USM has a focal range of 35-350mm and 10.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 56 - 560mm.