The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 45mm F1.8 Di VC USD and the Nikon 50mm f1.8G 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 45mm F1.8 Di VC USD is the longer of the two lenses at 92mm. The Nikon 50mm f1.8G with a length of 53mm, is 39mm shorter. Besides being longer, the Tamron 45mm F1.8 Di VC USD also has a larger diameter of 80mm compared to the Nikon 50mm f1.8G's 72mm 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 50mm f1.8G weighs 185g, 64% (335g) lighter than the Tamron 45mm F1.8 Di VC USD's weight of 520g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Nikon F (FX) Mount for size comparison purposes.
Standard Lenses in Nikon F (FX) Mount for Size Comparison
Filter Threads
The Tamron 45mm F1.8 Di VC USD has a filter size of 67mm whereas the Nikon 50mm f1.8G has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 45mm F1.8 Di VC USD:
And these are the 58mm filters that we recommend for the Nikon 50mm f1.8G:
Lens Mounts
Both the Tamron 45mm F1.8 Di VC USD and the Nikon 50mm f1.8G has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Tamron 45mm F1.8 Di VC USD is also available in Canon EF and Sony Alpha mounts.
Focal Range
Tamron 45mm F1.8 Di VC USD is a prime lens with fixed focal lenght of 45mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
67.5mm.
On the other hand, the Nikon 50mm f1.8G is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 75mm.