| Sigma 20mm f/1.8 EX Specifications | |
| Frame Coverage | 35mm |
| Lens Construction (groups) | 11 |
| Lens Construction (elements) | 13 |
| No. of Diaphragm Blades | 9 |
| Minimum Aperture | 22 |
| Closest Focusing Distance | 0.20m (7.9") |
| Maximum Magnifcation | 0.25x |
| Filter Diameter | 82mm |
| Maximum Diameter x Length | 88.6mm x 89.5mm (3.5" x 3.5") |
| Weight | 130g (4.6oz) |
Reviews
Source
Eric Tischer
To my eye the Sigma 20mm is identical to the Sigma 12-24mm from f/5.6 and down. Unless you need the extra speed or macro ablity, there's isn't much incentive to upgrade.
PhotoZone.de
Minimum aperture is definitely impressive and though the lens is not very sharp at f/1.8 there are many situations when you are simply happy that you can make pictures at all even when they are not absolutely sharp.
William Castleman
The EF 17-40mm f/4L lens is a very sharp, high contrast zoom lens with performance characteristics that often match and sometimes exceed those of quality prime lenses at wide angle.
The-Digital-Picture.com
Meet the Sigma 20mm f/1.8 EX DG Lens - as of this writing, Canon does not offer a lens this wide with an aperture this large. The Sigma 20mm is over 1 stop faster than the fastest Canon 20mm prime or zoom lenses (f/2.8).
Petteri Sulonen
It does something no other Canon-mount lens does -- a solid 20 mm down to f/2.8, and then over a stop more. And it's not even expensive.
