The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron AF 18-270mm f3.5-6.3 II VC LD and the Voigtlander 20mm F3.5 SL II 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 AF 18-270mm f3.5-6.3 II VC LD is the longer of the two lenses at 101mm. The Voigtlander 20mm F3.5 SL II with a length of 29mm, is 72mm shorter. Besides being longer, the Tamron AF 18-270mm f3.5-6.3 II VC LD also has a larger diameter of 80mm compared to the Voigtlander 20mm F3.5 SL II's 63mm 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. Voigtlander 20mm F3.5 SL II weighs 205g, 63% (355g) lighter than the Tamron AF 18-270mm f3.5-6.3 II VC LD's weight of 560g.
Filter Threads
The Tamron AF 18-270mm f3.5-6.3 II VC LD has a filter size of 72mm whereas the Voigtlander 20mm F3.5 SL II has a 52mm 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 Tamron AF 18-270mm f3.5-6.3 II VC LD:
And these are the 52mm filters that we recommend for the Voigtlander 20mm F3.5 SL II:
Lens Mounts
The Tamron AF 18-270mm f3.5-6.3 II VC LD has the Nikon F (DX) lens mount whereas the Voigtlander 20mm F3.5 SL II has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Tamron AF 18-270mm f3.5-6.3 II VC LD is also available in Canon EF mount.
Voigtlander 20mm F3.5 SL II is also available in Canon EF and Pentax KAF mounts.
Focal Range
Tamron AF 18-270mm f3.5-6.3 II VC LD has a focal range of 18-270mm and
15.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-405mm when used on a APS-C / DX format camera.
On the other hand, the Voigtlander 20mm F3.5 SL II is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 30mm.