The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony DT 18-250mm F3.5-6.3 and the Sony DT 18-135mm F3.5-5.6 SAM for their suitability to various photography scenarios:
Size and Weight Comparison
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. Sony DT 18-135mm F3.5-5.6 SAM weighs 398g, 9% (42g) lighter than the Sony DT 18-250mm F3.5-6.3's weight of 440g.
Filter Threads
Both the Sony DT 18-250mm F3.5-6.3 and the Sony DT 18-135mm F3.5-5.6 SAM have the same Filter thread size of 62mm.
Below are links to the 62mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Sony DT 18-250mm F3.5-6.3 and the Sony DT 18-135mm F3.5-5.6 SAM has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A68, Sony A77 II and Sony A58.
Focal Range
Sony DT 18-250mm F3.5-6.3 has a focal range of 18-250mm and
13.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-375mm when used on a APS-C / DX format camera.
On the other hand, the Sony DT 18-135mm F3.5-5.6 SAM 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.