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 Pentax DA 50-135mm F2.8 ED 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. Pentax DA 50-135mm F2.8 ED is the longer of the two lenses at 136mm. The Venus 105mm F2 with a length of 99mm, is 37mm shorter. Besides being longer, the Pentax DA 50-135mm F2.8 ED also has a larger diameter of 77mm compared to the Venus 105mm F2's 76mm 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 DA 50-135mm F2.8 ED weighs 685g, 8% (60g) lighter than the Venus 105mm F2's weight of 745g.
Filter Threads
Both the Venus 105mm F2 and the Pentax DA 50-135mm F2.8 ED have the same Filter thread size of 67mm.
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Venus 105mm F2 and the Pentax DA 50-135mm F2.8 ED has the same Pentax KAF2 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF2 lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Venus 105mm F2 is also available in the Sony E , 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 Pentax DA 50-135mm F2.8 ED has a focal range of 50-135mm and 2.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 75-202.5mm when used on a APS-C / DX format camera.
