The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 18-135mm F3.5-5.6ED and the Pentax 16-45mm F4 ED AL 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 16-45mm F4 ED AL is the longer of the two lenses at 92mm. The Pentax 18-135mm F3.5-5.6ED with a length of 76mm, is 16mm shorter. On the other hand, the Pentax 18-135mm F3.5-5.6ED has a larger diameter of 73mm compared to the Pentax 16-45mm F4 ED AL'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. Pentax 16-45mm F4 ED AL weighs 356g, 12% (49g) lighter than the Pentax 18-135mm F3.5-5.6ED's weight of 405g.
Filter Threads
The Pentax 18-135mm F3.5-5.6ED has a filter size of 62mm whereas the Pentax 16-45mm F4 ED AL has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Pentax 18-135mm F3.5-5.6ED:
And these are the 67mm filters that we recommend for the Pentax 16-45mm F4 ED AL:
Lens Mounts
The Pentax 18-135mm F3.5-5.6ED has the Pentax KAF3 lens mount whereas the Pentax 16-45mm F4 ED AL has the Pentax 645AF2 lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Pentax KAF3 Mount and , and for the Pentax 645AF2 Mount.
Focal Range
Pentax 18-135mm F3.5-5.6ED has a focal range of 18-135mm and
7.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-202.5mm when used on a APS-C / DX format camera.
On the other hand, the Pentax 16-45mm F4 ED AL has a focal range of 16-45mm and 2.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-67.5mm when used on a APS-C / DX format camera.
