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 Zeiss Otus 1.4/55 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 Zeiss Otus 1.4/55 with a length of 141mm, is 30mm shorter. Besides being longer, the Sigma 50-100mm F1.8 A also has a larger diameter of 94mm compared to the Zeiss Otus 1.4/55's 92mm 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. Zeiss Otus 1.4/55 weighs 970g, 34% (520g) 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 Zeiss Otus 1.4/55 has a 77mm 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 77mm filters that we recommend for the Zeiss Otus 1.4/55:
Lens Mounts
Both the Sigma 50-100mm F1.8 A and the Zeiss Otus 1.4/55 has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Sigma 50-100mm F1.8 A is also available in Nikon F (DX) and Sigma SA mounts.
Zeiss Otus 1.4/55 is also available in Nikon F (FX) mount.
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
80-160mm when used on a APS-C / DX format camera.
On the other hand, the Zeiss Otus 1.4/55 is a prime lens with fixed focal lenght of 55mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 88mm.