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 18-50mm F2.8-4.5 DC OS HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sigma 18-50mm F2.8-4.5 DC OS HSM is the longer of the two lenses at 89mm. The Lensbaby Velvet 56 with a length of 86mm, is 3mm shorter. Besides being longer, the Sigma 18-50mm F2.8-4.5 DC OS HSM also has a larger diameter of 74mm compared to the Lensbaby Velvet 56's 72mm diameter.
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 18-50mm F2.8-4.5 DC OS HSM weighs 395g, 1% (5g) lighter than the Lensbaby Velvet 56's weight of 400g.
Filter Threads
The Lensbaby Velvet 56 has a filter size of 62mm whereas the Sigma 18-50mm F2.8-4.5 DC OS HSM has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Lensbaby Velvet 56:
And these are the 67mm filters that we recommend for the Sigma 18-50mm F2.8-4.5 DC OS HSM:
Lens Mounts
Both the Lensbaby Velvet 56 and the Sigma 18-50mm F2.8-4.5 DC OS 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 the Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF3, Samsung NX and Sony E mounts.
Sigma 18-50mm F2.8-4.5 DC OS HSM is also available in Canon EF , Pentax KAF3, Sigma SA and Nikon F (DX) 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.
On the other hand, the Sigma 18-50mm F2.8-4.5 DC OS HSM has a focal range of 18-50mm and 2.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-75mm when used on a APS-C / DX format camera.