The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Irix 45mm F1.4 and the Nikon 17-55mm f2.8G ED-IF for their suitability to various photography scenarios:
Size and Weight Comparison
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 17-55mm f2.8G ED-IF weighs 755g, 18% (170g) lighter than the Irix 45mm F1.4's weight of 925g.
Filter Threads
Both the Irix 45mm F1.4 and the Nikon 17-55mm f2.8G ED-IF have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
The Irix 45mm F1.4 has the Nikon F (FX) lens mount whereas the Nikon 17-55mm f2.8G ED-IF has the Nikon F (DX) 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 (FX) Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Irix 45mm F1.4 is also available in the Canon EF and Pentax KAF2 mounts.
Focal Range
Irix 45mm F1.4 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 17-55mm f2.8G ED-IF has a focal range of 17-55mm and 3.2X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 25.5-82.5mm when used on a APS-C / DX format camera.
