The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 20-70mm F4 G and the Tamron AF 28-200mm f3.8-5.6 XR 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. Sony FE 20-70mm F4 G is the longer of the two lenses at 99mm. The Tamron AF 28-200mm f3.8-5.6 XR with a length of 75mm, is 24mm shorter. Besides being longer, the Sony FE 20-70mm F4 G also has a larger diameter of 79mm compared to the Tamron AF 28-200mm f3.8-5.6 XR's 71mm 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 28-200mm f3.8-5.6 XR weighs 354g, 27% (134g) lighter than the Sony FE 20-70mm F4 G's weight of 488g.
Filter Threads
The Sony FE 20-70mm F4 G has a filter size of 72mm whereas the Tamron AF 28-200mm f3.8-5.6 XR 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 72mm filters that we recommend you to consider for the Sony FE 20-70mm F4 G:
And these are the 62mm filters that we recommend for the Tamron AF 28-200mm f3.8-5.6 XR:
Lens Mounts
The Sony FE 20-70mm F4 G has the Sony E lens mount whereas the Tamron AF 28-200mm f3.8-5.6 XR has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Sony FX5, Sony A7R VI and Sony A7 V for the Sony E Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron AF 28-200mm f3.8-5.6 XR is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
Sony FE 20-70mm F4 G has a focal range of 20-70mm and
3.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
30 - 105mm.
On the other hand, the Tamron AF 28-200mm f3.8-5.6 XR has a focal range of 28-200mm and 7.1X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 42 - 300mm.
