The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 15mm f1.4 DC C and the Samyang 35mm F1.2 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. Samyang 35mm F1.2 is the longer of the two lenses at 74mm. The Sigma 15mm f1.4 DC C with a length of 65mm, is 9mm shorter. Besides being longer, the Samyang 35mm F1.2 also has a larger diameter of 68mm compared to the Sigma 15mm f1.4 DC 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. Sigma 15mm f1.4 DC C weighs 225g, which means it is 195g (46%) lighter than the Samyang 35mm F1.2 which has a weight of 420g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Fujifilm X Mount for size comparison purposes.
Wideangle Lenses in Fujifilm X Mount for Size Comparison
Filter Threads
The Sigma 15mm f1.4 DC C has a filter size of 58mm whereas the Samyang 35mm F1.2 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 58mm filters that we recommend you to consider for the Sigma 15mm f1.4 DC C:
And these are the 62mm filters that we recommend for the Samyang 35mm F1.2:
Lens Mounts
Both the Sigma 15mm f1.4 DC C and the Samyang 35mm F1.2 has the same Fujifilm X lens mount. Some of the latest released cameras that are compatible with the Fujifilm X lenses are Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5.
Sigma 15mm f1.4 DC C is also available in the Canon RF and Sony E mounts.
Samyang 35mm F1.2 is also available in Canon EF-M , Micro Four Thirds and Sony E mounts.
Focal Range
Sigma 15mm f1.4 DC C is a prime lens with fixed focal lenght of 15mm which has an effective (full-frame 35mm equivalent) focal range of
22.5mm when used on a APS-C / DX format camera.
On the other hand, the Samyang 35mm F1.2 is a prime lens with fixed focal lenght of 35mm which has an effective (full-frame 35mm equivalent) focal range of 52.5mm when used on a APS-C / DX format camera.