The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 18-35mm F1.8 DC HSM and the Sigma 10-20mm F3.5 EX DC 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 18-35mm F1.8 DC HSM is the longer of the two lenses at 121mm. The Sigma 10-20mm F3.5 EX DC HSM with a length of 88mm, is 33mm shorter. On the other hand, the Sigma 10-20mm F3.5 EX DC HSM has a larger diameter of 87mm compared to the Sigma 18-35mm F1.8 DC HSM's 78mm 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 10-20mm F3.5 EX DC HSM weighs 520g, 35% (290g) lighter than the Sigma 18-35mm F1.8 DC HSM's weight of 810g.
Filter Threads
The Sigma 18-35mm F1.8 DC HSM has a filter size of 72mm whereas the Sigma 10-20mm F3.5 EX DC HSM has a 82mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Sigma 18-35mm F1.8 DC HSM:
And these are the 82mm filters that we recommend for the Sigma 10-20mm F3.5 EX DC HSM:
Lens Mounts
The Sigma 18-35mm F1.8 DC HSM has the Canon EF lens mount whereas the Sigma 10-20mm F3.5 EX DC HSM has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Sigma 18-35mm F1.8 DC HSM is also available in the Pentax KAF , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Sigma 10-20mm F3.5 EX DC HSM is also available in Canon EF , Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 18-35mm F1.8 DC HSM has a focal range of 18-35mm and
1.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
28.8-56mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 10-20mm F3.5 EX DC HSM has a focal range of 10-20mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-30mm when used on a APS-C / DX format camera.
