The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Irix 45mm F1.4 and the Sigma 50mm F1.4 DG HSM A for their suitability to various photography scenarios:
Size and Weight Comparison
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 50mm F1.4 DG HSM A weighs 815g, 11% (110g) lighter than the Irix 45mm F1.4's weight of 925g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Canon EF Mount for size comparison purposes.
Standard Lenses in Canon EF Mount for Size Comparison
Filter Threads
Both the Irix 45mm F1.4 and the Sigma 50mm F1.4 DG HSM A have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Irix 45mm F1.4 and the Sigma 50mm F1.4 DG HSM A has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K.
Irix 45mm F1.4 is also available in the Nikon F (FX) and Pentax KAF2 mounts.
Sigma 50mm F1.4 DG HSM A is also available in Sony Alpha , Sigma SA, Nikon F (FX) and Leica L mounts.
Focal Range
Irix 45mm F1.4 is a prime lens with fixed focal lenght of 45mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
72mm.
On the other hand, the Sigma 50mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 80mm.
