The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang XP 35mm F1.2 and the Tamron 45mm F1.8 Di VC USD 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. Samyang XP 35mm F1.2 is the longer of the two lenses at 117mm. The Tamron 45mm F1.8 Di VC USD with a length of 92mm, is 25mm shorter. Besides being longer, the Samyang XP 35mm F1.2 also has a larger diameter of 93mm compared to the Tamron 45mm F1.8 Di VC USD's 80mm diameter.
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. Tamron 45mm F1.8 Di VC USD weighs 540g, 51% (566g) lighter than the Samyang XP 35mm F1.2's weight of 1106g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Canon EF Mount for size comparison purposes.
Standard Prime Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Samyang XP 35mm F1.2 and the Tamron 45mm F1.8 Di VC USD has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron 45mm F1.8 Di VC USD is also available in Nikon F (FX) and Sony Alpha mounts.
Focal Range
Samyang XP 35mm F1.2 is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 52.5mm.
Tamron 45mm F1.8 Di VC USD 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.