The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-70 F2.8 Di III-A VC and the Tamron AF 28-300mm f3.5-6.3 XR LD 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 17-70 F2.8 Di III-A VC is the longer of the two lenses at 119mm. The Tamron AF 28-300mm f3.5-6.3 XR LD with a length of 84mm, is 35mm shorter. Besides being longer, the Tamron 17-70 F2.8 Di III-A VC also has a larger diameter of 75mm compared to the Tamron AF 28-300mm f3.5-6.3 XR LD's 73mm 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. Tamron AF 28-300mm f3.5-6.3 XR LD weighs 420g, 19% (105g) lighter than the Tamron 17-70 F2.8 Di III-A VC's weight of 525g.
Filter Threads
The Tamron 17-70 F2.8 Di III-A VC has a filter size of 67mm whereas the Tamron AF 28-300mm f3.5-6.3 XR LD has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 17-70 F2.8 Di III-A VC:
And these are the 62mm filters that we recommend for the Tamron AF 28-300mm f3.5-6.3 XR LD:
Lens Mounts
The Tamron 17-70 F2.8 Di III-A VC has the Sony E lens mount whereas the Tamron AF 28-300mm f3.5-6.3 XR LD has the Sony Alpha lens mount. Some of the latest released cameras that are compatible with these mounts are Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount and Sony A99 II, Sony A68 and Sony A77 II for the Sony Alpha Mount.
Tamron 17-70 F2.8 Di III-A VC is also available in the Fujifilm X mount.
Tamron AF 28-300mm f3.5-6.3 XR LD is also available in Canon EF , Nikon F (FX) and Pentax KAF mounts.
Focal Range
Tamron 17-70 F2.8 Di III-A VC has a focal range of 17-70mm and
4.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-105mm when used on a APS-C / DX format camera.
On the other hand, the Tamron AF 28-300mm f3.5-6.3 XR LD has a focal range of 28-300mm and 10.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42 - 450mm.
