The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 24-70mm F2.8 GM and the Sigma 30mm F2.8 DN 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. Sony FE 24-70mm F2.8 GM is the longer of the two lenses at 136mm. The Sigma 30mm F2.8 DN with a length of 41mm, is 95mm shorter. Besides being longer, the Sony FE 24-70mm F2.8 GM also has a larger diameter of 88mm compared to the Sigma 30mm F2.8 DN's 61mm 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 30mm F2.8 DN weighs 135g, 84% (751g) lighter than the Sony FE 24-70mm F2.8 GM's weight of 886g.
Lens Mounts
Both the Sony FE 24-70mm F2.8 GM and the Sigma 30mm F2.8 DN has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony FX5, Sony A7R VI and Sony A7 V.
Sigma 30mm F2.8 DN is also available in Micro Four Thirds mount.
Focal Range
Sony FE 24-70mm F2.8 GM has a focal range of 24-70mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
36 - 105mm.
On the other hand, the Sigma 30mm F2.8 DN is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.
