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 30mm F1.4 EX DC HSM 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. Lensbaby Velvet 56 is the longer of the two lenses at 86mm. The Sigma 30mm F1.4 EX DC HSM with a length of 59mm, is 27mm shorter. On the other hand, the Sigma 30mm F1.4 EX DC HSM has a larger diameter of 77mm compared to the Lensbaby Velvet 56's 72mm 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. Lensbaby Velvet 56 weighs 400g, which means it is 30g (6%) lighter than the Sigma 30mm F1.4 EX DC HSM which has a weight of 430g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Sony Alpha Mount for size comparison purposes.
Standard Prime Lenses in Sony Alpha Mount for Size Comparison
Lens Mounts
Both the Lensbaby Velvet 56 and the Sigma 30mm F1.4 EX DC HSM has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Lensbaby Velvet 56 is also available in Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF3, Samsung NX and Sony E mounts.
Sigma 30mm F1.4 EX DC HSM is also available in Canon EF-S , Nikon F (DX), Four Thirds, Pentax KAF and Sigma SA 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 a 35mm (FF) equivalent of 84mm.
Sigma 30mm F1.4 EX DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.