The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Nikon 18-55mm F3.5-5.6G VR and the Nikon 20mm 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. Nikon 18-55mm F3.5-5.6G VR is the longer of the two lenses at 63mm. The Nikon 20mm f2.8D with a length of 43mm, is 20mm shorter. On the other hand, the Nikon 20mm f2.8D has a larger diameter of 69mm compared to the Nikon 18-55mm F3.5-5.6G VR'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. Nikon 18-55mm F3.5-5.6G VR weighs 205g, which means it is 65g (24%) lighter than the Nikon 20mm f2.8D which has a weight of 270g.
Filter Threads
The Nikon 18-55mm F3.5-5.6G VR has a filter size of 55mm whereas the Nikon 20mm f2.8D 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 55mm filters that we recommend you to consider for the Nikon 18-55mm F3.5-5.6G VR:
And these are the 62mm filters that we recommend for the Nikon 20mm f2.8D:
Lens Mounts
The Nikon 18-55mm F3.5-5.6G VR has the Nikon F (DX) lens mount whereas the Nikon 20mm 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.
Nikon 18-55mm F3.5-5.6G VR is also available in Nikon F (DX) mount.
Focal Range
Nikon 18-55mm F3.5-5.6G VR has a focal range of 18-55mm and
3.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-82.5mm when used on a APS-C / DX format camera.
On the other hand, the Nikon 20mm f2.8D 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.