Sigma unveils ultra-light 18-250mm macro zoom for travel photography

Sigma unveils new 18-250mm f3.5-6.3 DC Macro OS HSM travel zoom 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).

DO or Di? Your lens markings explained

DO or Di? All your lens markings explained

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.