The Sigma 10-20mm f/4-5.6 EX DC HSM Autofocus Zoom lens offers an ultra-wide zoom solution to digital cameras, and was exclusively designed to suit the characteristics of digital SLR cameras. The super wide-angle capability of this zoom lens (equivalent range of approx. 15-30mm when used with a Nikon digital SLR camera makes it a very powerful tool for both indoor and landscape photography.
DC lenses are exclusively designed for digital SLR cameras. The image circle (rear of lens) is made to match the smaller dimensions used for the image sensor on digital cameras. As a result, these lenses are also more compact and lightweight, and are better matched to digital SLR cameras.
EX lens series denotes excellence of engineering and new technology
Correction for various types of aberration provided by three SLD (Special Low Dispersion) glass element and two aspherical lenses
Equipped with the silent, responsive and high speed Hyper Sonic Motor and provides fulltime manual focus override
Minimum focusing distance of 9.4" (24 cm) at all focal lengths
The IF (Internal Focusing) design offers smooth and fast autofocus and non-rotating filter attachment
This is the magnifying factor of a lens. Macro lenses will often be described by their “magnification factor”. A lens with a 1:1 magnification factor produces a projected image on the sensor which is the same as the subject.
The individual pieces of glass that form the overall optical construction. Most lenses have between four and eleven elements to bend the light rays to ensure a perfectly formed image appears on the light sensitive surface, such as a film or CCD. The elements are arranged in groups and may be seen in specification sheets as, for example, 6 elements in 4 groups. That configuration may have two single elements and the other four grouped in pairs.
A lens with a 1:1 magnification factor produces a projected image on the sensor which is the same as the subject. A 1:1 magnification factor is usually considered the minimum for a lens to be described as a “macro” lens. Specialist macro lenses are often 1:3 or even 1:10 magnification factors, meaning that 1mm across the subject becomes 3mm or 10mm when projected onto the sensor, thus 3 or 10 times magnification.