The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-20mm F4-5.6 EX DC HSM and the Olympus ED 9-18mm f4.0-5.6 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. Sigma 10-20mm F4-5.6 EX DC HSM is the longer of the two lenses at 81mm. The Olympus ED 9-18mm f4.0-5.6 with a length of 73mm, is 8mm shorter. Besides being longer, the Sigma 10-20mm F4-5.6 EX DC HSM also has a larger diameter of 84mm compared to the Olympus ED 9-18mm f4.0-5.6's 80mm 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. Olympus ED 9-18mm f4.0-5.6 weighs 280g, 40% (190g) lighter than the Sigma 10-20mm F4-5.6 EX DC HSM's weight of 470g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Four Thirds Mount for size comparison purposes.
Ultra-Wideangle Lenses in Four Thirds Mount for Size Comparison
Filter Threads
The Sigma 10-20mm F4-5.6 EX DC HSM has a filter size of 77mm whereas the Olympus ED 9-18mm f4.0-5.6 has a 72mm 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 Sigma 10-20mm F4-5.6 EX DC HSM:
And these are the 72mm filters that we recommend for the Olympus ED 9-18mm f4.0-5.6:
Lens Mounts
Both the Sigma 10-20mm F4-5.6 EX DC HSM and the Olympus ED 9-18mm f4.0-5.6 has the same Four Thirds lens mount. Some of the latest released cameras that are compatible with the Four Thirds lenses are , and .
Sigma 10-20mm F4-5.6 EX DC HSM is also available in the Canon EF , Pentax KAF, Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Olympus ED 9-18mm f4.0-5.6 is also available in Micro Four Thirds mount.
Focal Range
Sigma 10-20mm F4-5.6 EX DC HSM has a focal range of 10-20mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-30mm when used on a APS-C / DX format camera.
On the other hand, the Olympus ED 9-18mm f4.0-5.6 has a focal range of 9-18mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 18-36mm when used on a FourThirds format camera.
