The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 50-100mm F1.8 A and the Nikon 50mm f1.4G 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. Sigma 50-100mm F1.8 A is the longer of the two lenses at 171mm. The Nikon 50mm f1.4G with a length of 54mm, is 117mm shorter. Besides being longer, the Sigma 50-100mm F1.8 A also has a larger diameter of 94mm compared to the Nikon 50mm f1.4G's 74mm 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 f1.4G weighs 290g, 80% (1200g) lighter than the Sigma 50-100mm F1.8 A's weight of 1490g.
Filter Threads
The Sigma 50-100mm F1.8 A has a filter size of 82mm whereas the Nikon 50mm f1.4G 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 82mm filters that we recommend you to consider for the Sigma 50-100mm F1.8 A:
And these are the 58mm filters that we recommend for the Nikon 50mm f1.4G:
Lens Mounts
The Sigma 50-100mm F1.8 A has the Nikon F (DX) lens mount whereas the Nikon 50mm f1.4G 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.
Sigma 50-100mm F1.8 A is also available in Canon EF and Sigma SA mounts.
Focal Range
Sigma 50-100mm F1.8 A has a focal range of 50-100mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
75-150mm when used on a APS-C / DX format camera.
On the other hand, the Nikon 50mm f1.4G 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.