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 Sigma 56mm F1.4 C 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 15mm f1.4 DC C is the longer of the two lenses at 63mm. The Sigma 56mm F1.4 C with a length of 60mm, is 3mm shorter. Besides being longer, the Sigma 15mm f1.4 DC C also has a larger diameter of 69mm compared to the Sigma 56mm F1.4 C's 67mm 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 240g, which means it is 40g (14%) lighter than the Sigma 56mm F1.4 C which has a weight of 280g.
Filter Threads
The Sigma 15mm f1.4 DC C has a filter size of 58mm whereas the Sigma 56mm F1.4 C has a 55mm 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 55mm filters that we recommend for the Sigma 56mm F1.4 C:
Lens Mounts
Both the Sigma 15mm f1.4 DC C and the Sigma 56mm F1.4 C has the same Canon RF lens mount. Some of the latest released cameras that are compatible with the Canon RF lenses are Canon R50 V, Canon R100 and Canon R50.
Sigma 15mm f1.4 DC C is also available in the Fujifilm X and Sony E mounts.
Sigma 56mm F1.4 C is also available in Fujifilm X and Nikon Z 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
24mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 56mm F1.4 C is a prime lens with fixed focal lenght of 56mm which has an effective (full-frame 35mm equivalent) focal range of 89.6mm when used on a APS-C / DX format camera.