The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 DC HSM and the Olympus M 25mm F1.8 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 Olympus M 25mm F1.8 with a length of 41mm, is 22mm shorter. Besides being longer, the Sigma 30mm F1.4 DC HSM also has a larger diameter of 74mm compared to the Olympus M 25mm F1.8's 56mm 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. Olympus M 25mm F1.8 weighs 136g, 68% (299g) lighter than the Sigma 30mm F1.4 DC HSM's weight of 435g.
Filter Threads
The Sigma 30mm F1.4 DC HSM has a filter size of 62mm whereas the Olympus M 25mm F1.8 has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Sigma 30mm F1.4 DC HSM:
And these are the 46mm filters that we recommend for the Olympus M 25mm F1.8:
Lens Mounts
The Sigma 30mm F1.4 DC HSM has the Canon EF lens mount whereas the Olympus M 25mm F1.8 has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount and OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount.
Sigma 30mm F1.4 DC HSM is also available in the Nikon F (DX) and Sigma SA mounts.
Focal Range
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.
On the other hand, the Olympus M 25mm F1.8 is a prime lens with fixed focal lenght of 25mm which has an effective (full-frame 35mm equivalent) focal range of 50mm when used on a FourThirds format camera.
