Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Nikon Micro-85mm f3.5G ED VR is the longer of the two lenses at 99mm. The Tokina atx-i 100mm F2.8 FF Macro with a length of 95mm is 4mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 73mm.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Nikon Micro-85mm f3.5G ED VR weighs 355g, 33% (175g) lighter than the Tokina atx-i 100mm F2.8 FF Macro's weight of 530g.
Both Tokina atx-i 100mm F2.8 FF Macro has the Nikon F (FX) lens mount whereas the Nikon Micro-85mm f3.5G ED VR 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.
Tokina atx-i 100mm F2.8 FF Macro is also available in Canon EF , Canon EF and Nikon F (FX) mounts.
Tokina atx-i 100mm F2.8 FF Macro is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 150mm.
Nikon Micro-85mm f3.5G ED VR is a prime lens with fixed focal lenght of 85mm which has a 35mm equivalent focal range of 150mm when used on a APS-C / DX format camera.