The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 56mm F1.4 C and the Canon RF-S 18-45mm f4.5-6.3 IS 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 56mm F1.4 C is the longer of the two lenses at 60mm. The Canon RF-S 18-45mm f4.5-6.3 IS with a length of 44mm, is 16mm shorter. On the other hand, the Canon RF-S 18-45mm f4.5-6.3 IS 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. Canon RF-S 18-45mm f4.5-6.3 IS weighs 130g, 53% (150g) lighter than the Sigma 56mm F1.4 C's weight of 280g.
Filter Threads
The Sigma 56mm F1.4 C has a filter size of 55mm whereas the Canon RF-S 18-45mm f4.5-6.3 IS has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 55mm filters that we recommend you to consider for the Sigma 56mm F1.4 C:
And these are the 49mm filters that we recommend for the Canon RF-S 18-45mm f4.5-6.3 IS:
Lens Mounts
Both the Sigma 56mm F1.4 C and the Canon RF-S 18-45mm f4.5-6.3 IS 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 56mm F1.4 C is also available in the Fujifilm X and Nikon Z mounts.
Focal Range
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.
On the other hand, the Canon RF-S 18-45mm f4.5-6.3 IS has a focal range of 18-45mm and 2.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 28.8-72mm when used on a APS-C / DX format camera.
