The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 25mm F2.8 2.5-5X Ultra Macro and the Carl Zeiss Distagon T2,8/21 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. Carl Zeiss Distagon T2,8/21 is the longer of the two lenses at 109mm. The Venus 25mm F2.8 2.5-5X Ultra Macro with a length of 65mm, is 44mm shorter. Besides being longer, the Carl Zeiss Distagon T2,8/21 also has a larger diameter of 87mm compared to the Venus 25mm F2.8 2.5-5X Ultra Macro's 82mm 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. Venus 25mm F2.8 2.5-5X Ultra Macro weighs 400g, which means it is 200g (33%) lighter than the Carl Zeiss Distagon T2,8/21 which has a weight of 600g.
Lens Mounts
The Venus 25mm F2.8 2.5-5X Ultra Macro has the Nikon F (DX) lens mount whereas the Carl Zeiss Distagon T2,8/21 has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Venus 25mm F2.8 2.5-5X Ultra Macro is also available in Canon EF , Pentax KAF2 and Sony E mounts.
Carl Zeiss Distagon T2,8/21 is also available in Canon EF and Pentax KAF mounts.
Focal Range
Venus 25mm F2.8 2.5-5X Ultra Macro is a prime lens with fixed focal lenght of 25mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
37.5mm.
On the other hand, the Carl Zeiss Distagon T2,8/21 is a prime lens with fixed focal lenght of 21mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 31.5mm.