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 F2.8 EX DG Macro 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 F2.8 EX DG Macro with a length of 67mm is 19mm shorter. Besides being longer, the Lensbaby Velvet 56 also has a larger diameter of 72mm compared to Sigma 50mm F2.8 EX DG Macro's 71mm 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. Sigma 50mm F2.8 EX DG Macro weighs 320g, 19% (80g) lighter than the Lensbaby Velvet 56's weight of 400g.
Lens Mounts
Both Lensbaby Velvet 56 has the Pentax KAF3 lens mount whereas the Sigma 50mm F2.8 EX DG Macro has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF3 Mount and Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF Mount.
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 F2.8 EX DG Macro is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
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 F2.8 EX DG Macro 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.