Sigma AF 20mm f1.4 DG DN Art lens for Lumix L-mount 

This full-frame, ultra-wide-angle prime is perfect for night sky photography, landscapes, interiors, weddings, travel and architecture.

Its ultra-wide aperture of F1.4 ensures very fast shutter speeds in lower light conditions, as well as a very shallow depth-of-field for pronounced subject separation.

• Aperture Range: f/1.4 to f/16
• Two SLD Elements
• Three Aspherical Elements
• Super Multilayer Coating
• Stepping AF Motor, MFL Switch
• Rounded 11-Blade Diaphragm
• 82mm Front Filter Thread
• Rear Filter Holder
• Durable Brass Bayonet Mount

The lens comes with a raft of pro-level features that includes an aperture ring with de-click and lock switches, an AFL button, a lockable lens hood, a rear filter holder, a Lens Heater Retainer and a manual focus lock feature.

The optical design includes two SLD and three aspherical elements, one of which is the largest double-sided aspherical glass element in Sigma’s history. These advanced optics ensure very minimal chromatic aberration, sagittal coma flare and image distortion, giving highly-detailed images with exceptional sharpness and accuracy from the centre to the periphery of the frame.

The 20mm has an exceptional optical performance, with almost no chromatic aberration, excellent corner sharpness and very well-controlled flare.

Professional feature-set

A range of controls on the lens include an AF/MF switch, a customisable AFL switch and switches to de-click and lock the aperture ring.

The lens also has a Manual Focus Lock switch that allows users to completely deactivate the focus ring once focus has been acquired, ensuring that focus won’t change should the ring be accidentally knocked.

Rear filter holder

The 20mm F1.4 has an 82mm filter thread at the front of the lens, as well as a filter holder at the rear. The rear filters (sold separately) are about the size of an SD card, so very small and light, and as they’re positioned between the camera and lens, don’t tend to get damaged or dirty. It’s easy to cut filters by hand from gel sheets as a special template is included with the lens.

High-performance optics

The 20mm F1.4 DG DN | Art delivers outstanding optical quality, with excellent rendering of detail right into the corners even wide open at F1.4.

The lens has an advanced optical design made up of 17 elements in 15 groups, including 3 aspherical elements and 2 SLD elements. This ensures razor-sharp results and helps to eliminate chromatic aberration, flare, distortion and vignetting.

Advanced optical coatings reduce flare and ghosting when working in bright direct sunlight, creating high-contrast images with rich colours and strong blacks.

Ideal for environmental portraits

Having an F1.4 aperture and therefore a very shallow depth-of-field makes this lens ideal for environmental portraits, where a subject is portrayed in context with their surroundings.

The shallow depth-of-field helps the subject stand out from the background.

Close-up shooting

With a magnification ratio of 1:6.1, the 20mm can shoot relatively close-up for an ultra-wide-angle lens. This equates to a minimum focusing distance (subject to sensor) of 23cm, which puts the subject about 12cm from the end of the lens. This, combined with a shallow depth-of-field, makes for attractive close-up images.

Outstanding build quality

The exceptional build quality of the 20mm F1.4 DG DN is exactly as you’d expect from an Art-line lens, both in the materials used, the overall ergonomics and the quality of craftsmanship.

The exterior barrel is made of a polycarbonate called Thermally Stable Composite (TSC). Not only is this very strong and light, but it has a similar thermal expansion rate to aluminium. This ensures that the interior aluminium parts and the exterior TSC parts behave in the same way as temperatures change.

The focus ring is rubberised for easier operation, and focusing is internal, meaning the lens never changes length. This makes it ideal for use on a gimbal as the centre of gravity remains fairly constant.

Towards the rear of the barrel is an aperture ring, which can be de-clicked for stepless aperture changes. When put into Auto, aperture is controlled by the camera. A lock switch allows users to lock the ring in Auto or Manual so it’s not accidentally knocked into a different setting

To reduce flare and ghosting in bright sun, and to help protect the front element from damage, the lens has a robust petal-type lens hood with lock button. A rubberised ring on the hood makes for easier removal and fitting.

The durable brass mount is surrounded by a rubber seal to help keep out dust and moisture.

Made in Japan

All Sigma cameras and lenses are designed, manufactured and assembled at Sigma’s sole factory at Aizu in Japan. This domestic production model is unusual in today’s industry, with most imaging companies opting to outsource to other countries to reduce costs. But SIGMA believes that keeping virtually all manufacturing, processing and assembly in Aizu is essential for creating innovative, carefully thought-out and impeccably constructed products that meet the high standards demanded by professional photographers and film-makers around the world.