The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 C and the Fujifilm 35mm F1.4 R for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sigma 30mm F1.4 C is the longer of the two lenses at 73mm. The Fujifilm 35mm F1.4 R with a length of 55mm, is 18mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 65mm.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Fujifilm 35mm F1.4 R weighs 187g, 29% (78g) lighter than the Sigma 30mm F1.4 C's weight of 265g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Fujifilm X Mount for size comparison purposes.
Standard Prime Lenses in Fujifilm X Mount for Size Comparison
Lens Mounts
Both the Sigma 30mm F1.4 C and the Fujifilm 35mm F1.4 R has the same Fujifilm X lens mount. Some of the latest released cameras that are compatible with the Fujifilm X lenses are Fujifilm X-S20, Fujifilm X-T5 and Fujifilm X-H2.
Sigma 30mm F1.4 C is also available in Sony E , Micro Four Thirds and Nikon Z mounts.
Focal Range
Sigma 30mm F1.4 C is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera. Fujifilm 35mm F1.4 R 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.