The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-50mm f2.8 XR II VC LD and the Pentax 18-55mm F3.5-5.6 ED 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. Tamron 17-50mm f2.8 XR II VC LD is the longer of the two lenses at 95mm. The Pentax 18-55mm F3.5-5.6 ED II with a length of 68mm, is 27mm shorter. Besides being longer, the Tamron 17-50mm f2.8 XR II VC LD also has a larger diameter of 80mm compared to the Pentax 18-55mm F3.5-5.6 ED II's 68mm 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 18-55mm F3.5-5.6 ED II weighs 220g, 61% (350g) lighter than the Tamron 17-50mm f2.8 XR II VC LD's weight of 570g.
Filter Threads
The Tamron 17-50mm f2.8 XR II VC LD has a filter size of 72mm whereas the Pentax 18-55mm F3.5-5.6 ED II has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Tamron 17-50mm f2.8 XR II VC LD:
And these are the 52mm filters that we recommend for the Pentax 18-55mm F3.5-5.6 ED II:
Lens Mounts
The Tamron 17-50mm f2.8 XR II VC LD has the Nikon F (DX) lens mount whereas the Pentax 18-55mm F3.5-5.6 ED II has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Tamron 17-50mm f2.8 XR II VC LD is also available in the Canon EF mount.
Focal Range
Tamron 17-50mm f2.8 XR II VC LD has a focal range of 17-50mm and
2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-75mm when used on a APS-C / DX format camera.
On the other hand, the Pentax 18-55mm F3.5-5.6 ED II has a focal range of 18-55mm and 3.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-82.5mm when used on a APS-C / DX format camera.
