The Sigma 10-18mm f/2.8 DC DN Contemporary is a wide angle zoom lens designed for APS-C cameras, and it’s now available for Canon RF mounts. This lens offers a bright maximum aperture and caters to those needing an ultra-wide field of view without sacrificing low-light capabilities. Here's what you can expect from it.
Coming to you from Christopher Frost, this detailed video covers why the Sigma 10-18mm f/2.8 is an important addition for Canon APS-C users. Unlike the Canon 10-18mm lens, which has a much darker maximum aperture of f/4.5 to f/6.3, the Sigma allows for significantly more light at its widest settings. That makes a huge difference if you're shooting in low-light environments. Frost also notes that while the Sigma lens costs more, the f/2.8 aperture gives it a clear advantage, especially for those who need that extra flexibility without using full frame gear.
In terms of build quality, Frost points out that the lens is compact and lightweight at just 260 grams, making it easy to use on gimbals or for handheld video work. The body is plastic but feels solid, and it’s equipped with a weather-sealed metal mount. The autofocus motor is another standout, working almost silently and with accuracy, even when tested on a Canon EOS R7, a camera with a high-resolution 32-megapixel sensor. This makes the lens a great option for both stills and video, providing reliable tracking without the noise that can interfere with your recordings.
The optical performance of the 10-18mm f/2.8 is impressive, though not without some minor drawbacks. Frost highlights that at 10mm, the center sharpness is excellent, but the corners soften noticeably, especially wide open. Stopping down to f/5.6 improves corner sharpness considerably, and by f/8, the entire frame looks sharp. However, diffraction begins to soften the image at f/11, especially on high-resolution sensors like the Canon EOS R7. If you're using a 24-megapixel sensor, these issues will be less apparent, and the overall performance will be more than satisfactory. Check out the video above for the full rundown from Frost.
