The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 28-70mm F2.8 DG DN C and the Panasonic X 35-100mm F2.8 II Power OIS 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 28-70mm F2.8 DG DN C is the longer of the two lenses at 102mm. The Panasonic X 35-100mm F2.8 II Power OIS with a length of 100mm, is 2mm shorter. Besides being longer, the Sigma 28-70mm F2.8 DG DN C also has a larger diameter of 72mm compared to the Panasonic X 35-100mm F2.8 II Power OIS's 67mm diameter.
ss
Below you can find a scaled side-by-side image of Sigma 28-70mm F2.8 DG DN C and Panasonic X 35-100mm F2.8 II Power OIS to get a better idea of how their sizes compare in real life.
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 X 35-100mm F2.8 II Power OIS weighs 357g, 24% (113g) lighter than the Sigma 28-70mm F2.8 DG DN C's weight of 470g.
Filter Threads
The Sigma 28-70mm F2.8 DG DN C has a filter size of 67mm whereas the Panasonic X 35-100mm F2.8 II Power OIS has a 58mm 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 28-70mm F2.8 DG DN C:
And these are the 58mm filters that we recommend for the Panasonic X 35-100mm F2.8 II Power OIS:
Lens Mounts
The Sigma 28-70mm F2.8 DG DN C has the Sony E lens mount whereas the Panasonic X 35-100mm F2.8 II Power OIS has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Sony A9 III, Sony A7C Mark II and Sony A7CR for the Sony E Mount and OM System OM-1 II, Panasonic G9 II and OM System OM-5 for the Micro Four Thirds Mount.
Sigma 28-70mm F2.8 DG DN C is also available in Leica L mount.
Focal Range
Sigma 28-70mm F2.8 DG DN C has a focal range of 28-70mm and
2.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
42 - 105mm.
On the other hand, the Panasonic X 35-100mm F2.8 II Power OIS has a focal range of 35-100mm and 2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 70-200mm when used on a FourThirds format camera.