The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-DA 11-18mm F2.8 and the Tamron 10-24mm f3.5-4.5 II LD 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. HD Pentax-DA 11-18mm F2.8 is the longer of the two lenses at 100mm. The Tamron 10-24mm f3.5-4.5 II LD with a length of 84mm, is 16mm shorter. Besides being longer, the HD Pentax-DA 11-18mm F2.8 also has a larger diameter of 90mm compared to the Tamron 10-24mm f3.5-4.5 II LD's 83mm 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 10-24mm f3.5-4.5 II LD weighs 406g, 42% (298g) lighter than the HD Pentax-DA 11-18mm F2.8's weight of 704g.
Filter Threads
The HD Pentax-DA 11-18mm F2.8 has a filter size of 82mm whereas the Tamron 10-24mm f3.5-4.5 II LD has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the HD Pentax-DA 11-18mm F2.8:
And these are the 77mm filters that we recommend for the Tamron 10-24mm f3.5-4.5 II LD:
Lens Mounts
The HD Pentax-DA 11-18mm F2.8 has the Pentax KAF3 lens mount whereas the Tamron 10-24mm f3.5-4.5 II LD has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron 10-24mm f3.5-4.5 II LD is also available in Canon EF , Nikon F (DX), Sony Alpha and Canon EF mounts.
Focal Range
HD Pentax-DA 11-18mm F2.8 has a focal range of 11-18mm and
1.6X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
16.5-27mm when used on a APS-C / DX format camera.
On the other hand, the Tamron 10-24mm f3.5-4.5 II LD has a focal range of 10-24mm and 2.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-36mm when used on a APS-C / DX format camera.
