The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 17-40mm f1.8 and the Sony FE 20-70mm F4 G 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 17-40mm f1.8 is the longer of the two lenses at 116mm. The Sony FE 20-70mm F4 G with a length of 99mm, is 17mm shorter. On the other hand, the Sony FE 20-70mm F4 G has a larger diameter of 79mm compared to the Sigma 17-40mm f1.8's 73mm diameter.
Below you can find a scaled side-by-side image of Sigma 17-40mm f1.8 and Sony FE 20-70mm F4 G to get a better idea of how their sizes compare in real life.
Comparison image of the Sigma 17-40mm f1.8 and the Sony FE 20-70mm F4 G Size and Weight 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. Sony FE 20-70mm F4 G weighs 488g, 8% (47g) lighter than the Sigma 17-40mm f1.8's weight of 535g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Sony E Mount for size comparison purposes.
Standard Sony E Mount
Filter Threads
The Sigma 17-40mm f1.8 has a filter size of 67mm whereas the Sony FE 20-70mm F4 G 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 67mm filters that we recommend you to consider for the Sigma 17-40mm f1.8:
And these are the 72mm filters that we recommend for the Sony FE 20-70mm F4 G:
Lens Mounts
Both the Sigma 17-40mm f1.8 and the Sony FE 20-70mm F4 G has the same Sony E lens mount . Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E10 II , Sony A6700 and Sony FX30 .
Leica L , Fujifilm X and Canon RF mounts.
Focal Range
Sigma 17-40mm f1.8 has a focal range of 17-40mm and
2.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-60mm when used on a APS-C / DX format camera.
On the other hand, the Sony FE 20-70mm F4 G has a focal range of 20-70mm and 3.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 30 - 105mm .
