The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 16-28mm F2.8 L and the Panasonic 7-14mm F4 ASPH 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 16-28mm F2.8 L is the longer of the two lenses at 101mm. The Panasonic 7-14mm F4 ASPH with a length of 83mm, is 18mm shorter. Besides being longer, the Sigma 16-28mm F2.8 L also has a larger diameter of 77mm compared to the Panasonic 7-14mm F4 ASPH's 70mm 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. Panasonic 7-14mm F4 ASPH weighs 300g, 33% (150g) lighter than the Sigma 16-28mm F2.8 L's weight of 450g.
Lens Mounts
The Sigma 16-28mm F2.8 L has the Leica L lens mount whereas the Panasonic 7-14mm F4 ASPH has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Leica SL3, Panasonic S5 II and Panasonic S5 II X for the Leica L Mount and OM System OM-1 II, Panasonic G9 II and OM System OM-5 for the Micro Four Thirds Mount.
Focal Range
Sigma 16-28mm F2.8 L has a focal range of 16-28mm and
1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
24 - 42mm.
On the other hand, the Panasonic 7-14mm F4 ASPH has a focal range of 7-14mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 14-28mm when used on a FourThirds format camera.