The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Lensbaby Velvet 56 and the Sigma 50mm F1.4 EX DG HSM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Lensbaby Velvet 56 is the longer of the two lenses at 86mm. The Sigma 50mm F1.4 EX DG HSM with a length of 68mm is 18mm shorter. On the other hand, the Sigma 50mm F1.4 EX DG HSM has a larger diameter of 85mm compared to Lensbaby Velvet 56's 72mm diameter.
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. Lensbaby Velvet 56 weighs 400g, which means it is 105g (20%) lighter than the Sigma 50mm F1.4 EX DG HSM which has a weight of 505g.
Below you can find the dimension and weight table of the 'Standard Prime Lenses in Pentax KAF3 Mount for size comparison purposes.
Standard Prime Lenses in Pentax KAF3 Mount for Size Comparison
Both Lensbaby Velvet 56 and Sigma 50mm F1.4 EX DG HSM has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax KF, Pentax K-3 III and Pentax K-1 II.
Lensbaby Velvet 56 is also available in Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Samsung NX, Sony Alpha and Sony E mounts.
Sigma 50mm F1.4 EX DG HSM is also available in Canon EF , Sony Alpha, Sigma SA, Nikon F (FX) and Four Thirds mounts.
Lensbaby Velvet 56 is a prime lens with fixed focal lenght of 56mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 84mm.
Sigma 50mm F1.4 EX DG HSM is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 75mm.