The Sigma 18-35mm f/1.8 DC HSM announced today is the first ever zoom lens to achieve a wide constant aperture of f/1.8 throughout the zoom range. Find out all the key specs of this new Sigma lens.
Independent lens maker Sigma has announced a new DSLR zoom lens designed for travellers and backpackers, or anyone who wants an all-purpose zoom lens that’s both light and small.
The Sigma 18-250mm f/3.5-6.3 DC Macro OS HSM is different because it’s been manufactured using a special polycarbonate material called Thermally Stable Composite (TSC).
Does your lens has more letters after its name than a retired rocket scientist. What do all these lens markings mean? You can refer to a lens simply by the name of the manufacturer, the focal length, and its maximum aperture – a Sigma 70-300mm f/4-5.6, say, or Canon 50mm f/1.4. But as lenses have often evolved from decades of development, they usually have a line of additional letters after their names, stamped on the barrel or printed on the boxes.
Some lens markings are about manufacturer branding – defining a more recent range, or a lens that’s built to higher standards than another. Others are to do with the optics themselves, and to highlight specific technologies used in the lens construction. In the jargon-busting guide below, we’ll translate these lens markings for you.
It’s available in all the same mounts as Sigma’s new, constant-aperture version of the lens, as well as in Olympus Four Thirds mount (although the effective zoom range of 20-40mm is less impressive
Both Sigma lenses use the company’s HyperSonic Motor (HSM) autofocus, which is practically as quiet as the equivalent Canon and Nikon systems, although it proved rather slower in our tests.