The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 105mm F2 and the Tamron 90mm f2.8 Macro 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. Venus 105mm F2 is the longer of the two lenses at 99mm. The Tamron 90mm f2.8 Macro with a length of 97mm, is 2mm shorter. Besides being longer, the Venus 105mm F2 also has a larger diameter of 76mm compared to the Tamron 90mm f2.8 Macro's 72mm 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. Tamron 90mm f2.8 Macro weighs 405g, 45% (340g) lighter than the Venus 105mm F2's weight of 745g.
Filter Threads
The Venus 105mm F2 has a filter size of 67mm whereas the Tamron 90mm f2.8 Macro has a 55mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Venus 105mm F2:
And these are the 55mm filters that we recommend for the Tamron 90mm f2.8 Macro:
Lens Mounts
The Venus 105mm F2 has the Pentax KAF2 lens mount whereas the Tamron 90mm f2.8 Macro has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF2 Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Venus 105mm F2 is also available in Sony E , Canon EF, Nikon F (FX) and Sony Alpha mounts.
Tamron 90mm f2.8 Macro is also available in Canon EF , Nikon F (FX) and Sony Alpha mounts.
Focal Range
Venus 105mm F2 is a prime lens with fixed focal lenght of 105mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
157.5mm.
On the other hand, the Tamron 90mm f2.8 Macro is a prime lens with fixed focal lenght of 90mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 135mm.