The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 15-30mm f2.8 VC USD and the Sony DT 11-18mm F4.5-5.6 for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Tamron 15-30mm f2.8 VC USD is the longer of the two lenses at 145mm. The Sony DT 11-18mm F4.5-5.6 with a length of 81mm is 64mm shorter. Besides being longer, the Tamron 15-30mm f2.8 VC USD also has a larger diameter of 98mm compared to Sony DT 11-18mm F4.5-5.6's 83mm 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. Sony DT 11-18mm F4.5-5.6 weighs 360g, 67% (740g) lighter than the Tamron 15-30mm f2.8 VC USD's weight of 1100g.
Below you can find the dimension and weight table of the 'Wideangle Zoom Lenses in Sony Alpha Mount for size comparison purposes.
Wideangle Zoom Lenses in Sony Alpha Mount for Size Comparison
Both Tamron 15-30mm f2.8 VC USD and Sony DT 11-18mm F4.5-5.6 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.
Tamron 15-30mm f2.8 VC USD is also available in Canon EF and Nikon F (FX) mounts.
Tamron 15-30mm f2.8 VC USD has a focal range of 15-30mm and 2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 22.5 - 45mm.
Sony DT 11-18mm F4.5-5.6 has a focal range of 11-18mm and 1.6X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 16.5-27mm when used on a APS-C / DX format camera.