Sigma 18-35mm f/1.8: first-ever zoom lens with f/1.8 constant aperture unveiled

    | News | 18/04/2013 11:22am
    Sigma 18-35mm f/1.8: first-ever zoom lens with wide constant aperture unveiled

    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.

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

    | News | 15/06/2012 11:21am
    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).

    Land of the giants: the world’s largest lenses

    | News | 19/05/2012 07:00am
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    Camera lenses come in many different sizes. We take a look at the unfathomably massive – the world’s largest SLR lenses for non-military use.

    DO or Di? Your lens markings explained

    | Photography Tips | 02/04/2012 13:58pm
    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.

    Fast lenses group test

    | Reviews | 14/01/2010 14:38pm

    A major bonus of fast lenses is that they allow you to use faster shutter speeds in low light, fending off the problems of both camera shake and motion blur, the latter of which can’t be fixe

    Sigma 10-20mm f/4-5.6 EX DC HSM Lens review

    | Reviews | 13/10/2009 12:37pm

    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

    Sigma 10-20mm f/3.5 EX DC HSM

    | Reviews | 13/10/2009 12:27pm

    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.

    Sigma DP2

    | Reviews | 10/09/2009 16:05pm

    Megapixels alone don’t guarantee image quality.

    Sigma DP2 Review

    | Reviews | 10/09/2009 16:05pm

    All makers but one use single-layer sensors, where the red, green and blue pixels are laid out in a pattern and the colour information for each pixel is interpolated using information from its neig