The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 18-250mm F3.5-6.3 DC OS HSM and the Sony 70-400mm F4-5.6 G SSM 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. Sony 70-400mm F4-5.6 G SSM II is the longer of the two lenses at 196mm. The Sigma 18-250mm F3.5-6.3 DC OS HSM with a length of 89mm, is 107mm shorter. Besides being longer, the Sony 70-400mm F4-5.6 G SSM II also has a larger diameter of 95mm compared to the Sigma 18-250mm F3.5-6.3 DC OS HSM's 74mm 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. Sigma 18-250mm F3.5-6.3 DC OS HSM weighs 470g, which means it is 1030g (68%) lighter than the Sony 70-400mm F4-5.6 G SSM II which has a weight of 1500g.
Below you can find the dimension and weight table of the SuperZoom Lenses in Sony Alpha Mount for size comparison purposes.
Super Telephoto Lenses in Sony Alpha Mount for Size Comparison
Filter Threads
The Sigma 18-250mm F3.5-6.3 DC OS HSM has a filter size of 72mm whereas the Sony 70-400mm F4-5.6 G SSM II 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 72mm filters that we recommend you to consider for the Sigma 18-250mm F3.5-6.3 DC OS HSM:
And these are the 77mm filters that we recommend for the Sony 70-400mm F4-5.6 G SSM II:
Lens Mounts
Both the Sigma 18-250mm F3.5-6.3 DC OS HSM and the Sony 70-400mm F4-5.6 G SSM II 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.
Sigma 18-250mm F3.5-6.3 DC OS HSM is also available in the Canon EF , Nikon F (DX), Pentax KAF3, Sigma SA, Canon EF, Nikon F (DX), Pentax KAF3, Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 18-250mm F3.5-6.3 DC OS HSM 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 70-400mm F4-5.6 G SSM II has a focal range of 70-400mm and 5.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 105 - 600mm.
