The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax smc 16-50mm F2.8 ED 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 smc 16-50mm F2.8 ED is the longer of the two lenses at 99mm. The Pentax 16-45mm F4 ED AL with a length of 92mm, is 7mm shorter. Besides being longer, the Pentax smc 16-50mm F2.8 ED also has a larger diameter of 84mm 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, 36% (209g) lighter than the Pentax smc 16-50mm F2.8 ED's weight of 565g.
Filter Threads
The Pentax smc 16-50mm F2.8 ED has a filter size of 77mm 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 77mm filters that we recommend you to consider for the Pentax smc 16-50mm F2.8 ED:
And these are the 67mm filters that we recommend for the Pentax 16-45mm F4 ED AL:
Lens Mounts
The Pentax smc 16-50mm F2.8 ED has the Pentax KAF2 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 KAF2 Mount and , and for the Pentax 645AF2 Mount.
Focal Range
Pentax smc 16-50mm F2.8 ED has a focal range of 16-50mm and
3.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
24-75mm 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.