The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Viltrox 9mm F2.8 X and the Tamron 17-70 F2.8 Di III-A VC 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 Viltrox 9mm F2.8 X with a length of 56mm, is 63mm shorter. Besides being longer, the Tamron 17-70 F2.8 Di III-A VC also has a larger diameter of 75mm compared to the Viltrox 9mm F2.8 X's 65mm 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. Viltrox 9mm F2.8 X weighs 175g, which means it is 350g (66%) lighter than the Tamron 17-70 F2.8 Di III-A VC which has a weight of 525g.
Filter Threads
The Viltrox 9mm F2.8 X has a filter size of 58mm whereas the Tamron 17-70 F2.8 Di III-A VC has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Viltrox 9mm F2.8 X:
And these are the 67mm filters that we recommend for the Tamron 17-70 F2.8 Di III-A VC:
Lens Mounts
The Viltrox 9mm F2.8 X has the Fujiflm X lens mount whereas the Tamron 17-70 F2.8 Di III-A VC 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 Fujiflm X Mount and Sony ZV-E10 II, Sony A6700 and Sony FX30 for the Sony E Mount.
Tamron 17-70 F2.8 Di III-A VC is also available in Fujifilm X mount.
Focal Range
Viltrox 9mm F2.8 X is a prime lens with fixed focal lenght of 9mm which has an effective (full-frame 35mm equivalent) focal range of
13.5mm when used on a APS-C / DX format camera.
On the other hand, the 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.
