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 Nikon Fisheye-16mm f2.8D 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 Nikon Fisheye-16mm f2.8D with a length of 57mm, is 44mm 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 Nikon Fisheye-16mm f2.8D'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. Nikon Fisheye-16mm f2.8D weighs 290g, 48% (270g) lighter than the Tamron AF 18-270mm f3.5-6.3 II VC LD's weight of 560g.
Lens Mounts
The Tamron AF 18-270mm f3.5-6.3 II VC LD has the Nikon F (DX) lens mount whereas the Nikon Fisheye-16mm f2.8D 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.
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 Nikon Fisheye-16mm f2.8D is a prime lens with fixed focal lenght of 16mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 24mm.