Produced in the legendary Aizu facility in Japan, Sigma presents their Sigma 10-20mm f/4-5.6 EX DC Lens. Building on 50 years of innovation in precision optics design and craftsmanship, the 10-20mm is an ultra wide angle zoom lens which encompasses several advance features designed to counter commonly found optical aberrations. Deep and ultra sharp images are produced as a result, making it a great value all round offering to any budding photographer.
Near-Far effect helps to push and pull subjects to give a longer field of viewClick here to view larger
Design features make up the foundation of the Sigma 10-20mm lens. Measuring just 8.1cm x 8.4cm and weighing an acceptable 470g, it is both lightweight and compact for its focal class, making it easy to handle but at the same time feel balanced when mounted on a DSLR. The lens features Sigma’s in-house developed inner focus system, which both eliminates the need to extend the barrel, reducing light loss, and the need to rotate the front lens. In staying fixed, the front lens can accommodate a petal design hood (included) that helps to counter light related issues such as glare. The inner focussing system also allows for the use of Circular Polarising filters. The lens is manufactured to Sigma’s high standards with the body constructed from strong but lightweight polycarbonate, layered in a hard-wear paint finish.
3 SLD and 3 Aspherical lens elements help to counter various colour and optical aberrationsClick here to view larger
With a small variable focal length from 10 to 20mm, this rectilinear lens is capable of capturing ultra wide angle images (102.4° to 63.8°) which become “exaggerated” in perspective. Thanks to higher aperture settings (f4-5.6), the depth of field appears greatly increased giving the added benefit of keeping all subjects in focus despite their varying distances. This effect also creates a near-far relationship where backgrounds seem to be pushed further away to make them appear smaller and closer subjects pulled nearer to make them appear bigger, creating a unique “stretched” effect. With a close focus distance of just 24cm, which stays consistent through all the focal lengths, you can capture subjects in their entirety whether standing close up or composing the image from a tight space. In anticipation of the regular inclusion of bright light sources (e.g. the sun), Sigma have also designed the lens to better cope with the undesirable effects of flare and glare.
In all forms of lens construction, Sigma puts the highest emphasis on the quality and craftsmanship of the internal optics. As a result, the 10-20mm incorporates a set of cutting edge and unique optical features which work to create bright and sharp images. Three out of fourteen lens elements are manufactured from Special Low Dispersion (SLD) glass, renowned for its high resolution and light transmission properties. They work in conjunction with one glass mould and two hybrid aspherical lens elements to counter various colour and optical aberrations which are commonly found in ultra wide angle lenses, such as chromatic aberration. Furthermore, the configuration also ensures that all levels of distortion are corrected. The resulting images speak for themselves in terms of sharpness and resolution.
Super Multi Layer coatings work to eliminate flare and ghost irregularitiesClick here to view larger
Finally, Sigma applies Super Multi Layer coatings to all lens elements, which work to create an optimum colour balance by reducing the damaging effects of ghost and flare. They also help to maximise light transmission to the DSLR’s sensor.
The lens features make it ideally suited to multiple uses including architectural photographyClick here to view larger
With an achievable focal length between 10-20mm and multiple specialist optical features, this Sigma lens is a perfect match for any photographer who would like to compose images with an ultra wide angle perspective*. Accurately, quickly and consistently these wide angle images can be produced both indoors and out, all with the same stunning results. Landscape and architectural photography are therefore perfectly suited to this type of lens. Furthermore, thanks to a permanent close focus distance and a high speed auto focus system, the lens would perform well in various forms of close-up photography. Finally, the compact and lightweight (for its class) design combined with the silent focus function, make the lens both portable and stealthy meaning it would work well when used out in the field accommodating wildlife photography as well as other specialist outdoor pursuits.
* only suitable for cameras with an APS-C size sensor