The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Nikon Micro-85mm f3.5G ED VR and the Pentax 40mm F2.8 L 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. Nikon Micro-85mm f3.5G ED VR is the longer of the two lenses at 99mm. The Pentax 40mm F2.8 L with a length of 15mm, is 84mm shorter. Besides being longer, the Nikon Micro-85mm f3.5G ED VR also has a larger diameter of 73mm compared to the Pentax 40mm F2.8 L's 63mm 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. Pentax 40mm F2.8 L weighs 80g, 77% (275g) lighter than the Nikon Micro-85mm f3.5G ED VR's weight of 355g.
Filter Threads
The Nikon Micro-85mm f3.5G ED VR has a filter size of 52mm whereas the Pentax 40mm F2.8 L has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 52mm filters that we recommend you to consider for the Nikon Micro-85mm f3.5G ED VR:
And these are the 49mm filters that we recommend for the Pentax 40mm F2.8 L:
Lens Mounts
The Nikon Micro-85mm f3.5G ED VR has the Nikon F (DX) lens mount whereas the Pentax 40mm F2.8 L has the Pentax KAF 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 Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Pentax 40mm F2.8 L is also available in Pentax KAF mount.
Focal Range
Nikon Micro-85mm f3.5G ED VR is a prime lens with fixed focal lenght of 85mm which has an effective (full-frame 35mm equivalent) focal range of
127.5mm when used on a APS-C / DX format camera.
On the other hand, the Pentax 40mm F2.8 L is a prime lens with fixed focal lenght of 40mm which has an effective (full-frame 35mm equivalent) focal range of 60mm when used on a APS-C / DX format camera.
