The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon EF 50mm f/1.8 STM and the Sigma 30mm F1.4 DC HSM 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 30mm F1.4 DC HSM is the longer of the two lenses at 63mm. The Canon EF 50mm f/1.8 STM with a length of 39mm, is 24mm shorter. Besides being longer, the Sigma 30mm F1.4 DC HSM also has a larger diameter of 74mm compared to the Canon EF 50mm f/1.8 STM's 69mm 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. Canon EF 50mm f/1.8 STM weighs 159g, which means it is 276g (63%) lighter than the Sigma 30mm F1.4 DC HSM which has a weight of 435g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Canon EF Mount for size comparison purposes.
Standard Lenses in Canon EF Mount for Size Comparison
Filter Threads
The Canon EF 50mm f/1.8 STM has a filter size of 49mm whereas the Sigma 30mm F1.4 DC HSM has a 62mm 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 Canon EF 50mm f/1.8 STM:
And these are the 62mm filters that we recommend for the Sigma 30mm F1.4 DC HSM:
Lens Mounts
Both the Canon EF 50mm f/1.8 STM and the Sigma 30mm F1.4 DC HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Sigma 30mm F1.4 DC HSM is also available in Nikon F (DX) and Sigma SA mounts.
Focal Range
Canon EF 50mm f/1.8 STM is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
80mm.
On the other hand, the Sigma 30mm F1.4 DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 48mm when used on a APS-C / DX format camera.