The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax DA 50-135mm F2.8 ED and the Panasonic X 35-100mm F2.8 II 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 Panasonic X 35-100mm F2.8 II with a length of 100mm, is 36mm shorter. Besides being longer, the Pentax DA 50-135mm F2.8 ED also has a larger diameter of 77mm compared to the Panasonic X 35-100mm F2.8 II's 67mm 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. Panasonic X 35-100mm F2.8 II weighs 357g, 47% (328g) lighter than the Pentax DA 50-135mm F2.8 ED's weight of 685g.
Filter Threads
The Pentax DA 50-135mm F2.8 ED has a filter size of 67mm whereas the Panasonic X 35-100mm F2.8 II has a 58mm 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 Pentax DA 50-135mm F2.8 ED:
And these are the 58mm filters that we recommend for the Panasonic X 35-100mm F2.8 II:
Lens Mounts
The Pentax DA 50-135mm F2.8 ED has the Pentax KAF2 lens mount whereas the Panasonic X 35-100mm F2.8 II has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Pentax KAF2 Mount and OM System OM-3 Astro, OM System OM-5 II and OM System OM-3 for the Micro Four Thirds Mount.
Focal Range
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.
On the other hand, the Panasonic X 35-100mm F2.8 II has a focal range of 35-100mm and 2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 70-200mm when used on a FourThirds format camera.
