The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 40mm F2.5 G and the Sigma 45mm F2.8 DG DN C 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 45mm F2.8 DG DN C is the longer of the two lenses at 46mm. The Sony FE 40mm F2.5 G with a length of 45mm, is 1mm shorter. On the other hand, the Sony FE 40mm F2.5 G has a larger diameter of 68mm compared to the Sigma 45mm F2.8 DG DN C's 64mm 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. Sony FE 40mm F2.5 G weighs 173g, which means it is 42g (19%) lighter than the Sigma 45mm F2.8 DG DN C which has a weight of 215g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Sony E Mount for size comparison purposes.
Standard Lenses in Sony E Mount for Size Comparison
Filter Threads
The Sony FE 40mm F2.5 G has a filter size of 49mm whereas the Sigma 45mm F2.8 DG DN C has a 55mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Sony FE 40mm F2.5 G:
And these are the 55mm filters that we recommend for the Sigma 45mm F2.8 DG DN C:
Lens Mounts
Both the Sony FE 40mm F2.5 G and the Sigma 45mm F2.8 DG DN C 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 45mm F2.8 DG DN C is also available in Leica L mount.
Focal Range
Sony FE 40mm F2.5 G is a prime lens with fixed focal lenght of 40mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
60mm.
On the other hand, the Sigma 45mm F2.8 DG DN C is a prime lens with fixed focal lenght of 45mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 67.5mm.
