The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus M 25mm F1.8 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 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, which means it is 299g (68%) lighter than the Sigma 30mm F1.4 DC HSM which has a weight of 435g.
Filter Threads
The Olympus M 25mm F1.8 has a filter size of 46mm 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 46mm filters that we recommend you to consider for the Olympus M 25mm F1.8:
And these are the 62mm filters that we recommend for the Sigma 30mm F1.4 DC HSM:
Lens Mounts
The Olympus M 25mm F1.8 has the Micro Four Thirds lens mount whereas the Sigma 30mm F1.4 DC HSM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount and Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount.
Sigma 30mm F1.4 DC HSM is also available in Nikon F (DX) and Sigma SA mounts.
Focal Range
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.
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.
