The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron SP 15-30mm F2.8 Di VC USD G2 and the Sigma 18-35mm F1.8 DC 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. Tamron SP 15-30mm F2.8 Di VC USD G2 is the longer of the two lenses at 145mm. The Sigma 18-35mm F1.8 DC HSM with a length of 121mm, is 24mm shorter. Besides being longer, the Tamron SP 15-30mm F2.8 Di VC USD G2 also has a larger diameter of 98mm compared to the Sigma 18-35mm F1.8 DC HSM's 78mm 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 18-35mm F1.8 DC HSM weighs 810g, 27% (300g) lighter than the Tamron SP 15-30mm F2.8 Di VC USD G2's weight of 1110g.
Lens Mounts
Both the Tamron SP 15-30mm F2.8 Di VC USD G2 and the Sigma 18-35mm F1.8 DC HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron SP 15-30mm F2.8 Di VC USD G2 is also available in Nikon F (FX) mount.
Sigma 18-35mm F1.8 DC HSM is also available in Pentax KAF , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
Tamron SP 15-30mm F2.8 Di VC USD G2 has a focal range of 15-30mm and
2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
24 - 48mm.
On the other hand, the Sigma 18-35mm F1.8 DC HSM has a focal range of 18-35mm and 1.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 28.8-56mm when used on a APS-C / DX format camera.