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 Sony E 18-135mm F3.5-5.6 OSS 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 Sony E 18-135mm F3.5-5.6 OSS with a length of 88mm, is 31mm shorter. Besides being longer, the Tamron 17-70 F2.8 Di III-A VC also has a larger diameter of 75mm compared to the Sony E 18-135mm F3.5-5.6 OSS's 67mm diameter.
Below you can find a scaled side-by-side image of Tamron 17-70 F2.8 Di III-A VC and Sony E 18-135mm F3.5-5.6 OSS to get a better idea of how their sizes compare in real life.
Comparison image of the Tamron 17-70 F2.8 Di III-A VC and the Sony E 18-135mm F3.5-5.6 OSS Size and Weight 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. Sony E 18-135mm F3.5-5.6 OSS weighs 325g, 38% (200g) 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 Sony E 18-135mm F3.5-5.6 OSS has a 55mm 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 55mm filters that we recommend for the Sony E 18-135mm F3.5-5.6 OSS:
Lens Mounts
The Tamron 17-70 F2.8 Di III-A VC has the Fujifilm X lens mount whereas the Sony E 18-135mm F3.5-5.6 OSS has the Sony E lens mount . Some of the latest released cameras that are compatible with these mounts are Fujifilm X-T30 III , Fujifilm X-E5 and Fujifilm X-M5 for the Fujifilm X Mount and Sony ZV-E10 II , Sony A6700 and Sony FX30 for the Sony E Mount.
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 Sony E 18-135mm F3.5-5.6 OSS has a focal range of 18-135mm and 7.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-202.5mm when used on a APS-C / DX format camera.
