20mm F2 DG DN

Outstanding wide-angle performance in an ultra-compact body

The SIGMA I series introduces compact, beautifully designed, high-performance optics for mirrorless camera systems. This 20mm ultra-wide-angle prime with its bright F2 aperture is exceptionally small and light for this type of lens, and is a superb option for landscape, night sky, interior and event photographers who need uncompromising optical quality, excellent portability and fast aperture performance.

Sitting within the contemporary line-up, the 20mm F2 DG DN is available for L-Mount and Sony E-mount cameras, and comes with an all-metal barrel, metal lens hood, magnetic lens cap and manual aperture ring. It is perfectly balanced on a mirrorless body, and unlike SIGMA’s 20mm F1.4 DG HSM | Art comes with a filter thread for added convenience.

New standards of optical quality in the Contemporary line

The 20mm F2 DG DN | Contemporary achieves the highest level of optical performance  even wide open, from the centre of the image to the periphery. Based on the latest optical design technology, the lens construction includes three high-precision glass-molded aspherical lens elements, one SLD element, and one FLD element to suppress a range of optical aberrations.

The result is clear and sharp images even in the extreme corners of the frame. By focusing on the suppression of sagittal coma flare, which is difficult to correct in post-processing, accurate reproduction of very bright points of light has been achieved. This provides extremely detailed results across the entire image, which is especially important for night sky photography. 

The lens’ advanced optical design, as well as its Super Multi-Layer Coating and Nano Porous Coating (NPC), ensures very minimal flare and ghosting even when shooting into bright light sources. This makes it much easier to photograph backlit subjects and still achieve punchy, high contrast results.

Exceptional optical quality for capturing ultra-sharp night sky images

Astrophotographers require lenses of the very highest quality, as all parts of the frame must be extremely sharp at the widest apertures and flare must be very well controlled. The 20mm F2 DG DN | Contemporary is an exceptionally capable astro lens, partly because of its extremely sharp results across the frame, and partly because it controls sagittal coma flare so effectively, where bright points of light, such as stars, can have a tendency to flare out near to the edges of the frame. Even wide open at F2, coma flare is very minimal right into the corners of the frame. Image: Kim Jennson

Compact and sharp: a perfect landscape lens

The lens’ ultra-wide 94.5° angle-of-view makes it a perfect choice for landscape photography. Outstanding optical performance right across the frame ensures sharp corners at all apertures. The advanced lens coatings ensure high-contrast results with vivid colours, which yields punchy and impactful images. A filter thread is included around the front element for easier filter use in the field. Image: Kim Jennson

Beautiful bokeh for wide-angle portraits

The 20mm is a very useful lens for weddings, events and environmental portraits, especially when working in tight spaces. The wide F2 aperture ensures fast shutter speeds, making it easier to shoot hand-held in low light, and it also gives a shallow depth-of-field for blurry backgrounds. The bokeh is smooth and attractive with circular highlights. Image: Jim Koepnick

A new experience for mirrorless users

The SIGMA I series features full-frame compatible lenses that offer new value to mirrorless systems. The combination of superb optical performance with a level of compactness that is perfectly suited to modern mirrorless cameras offer up new opportunities for a perfect shot.

SIGMA is aware that in today’s world we have a wide range of camera choices, especially with the increase in mobile phone ownership. But with many photographers looking for something more than something that simply captures images when they choose to own a camera and lens, I series lenses offer the ultimate combination of superb optical performance, outstanding usability and compact form-factor.

SIGMA’s excellence in development and production technologies has been built up since our founding in 1961 and became increasingly sophisticated with the introduction of the SIGMA Global Vision brand in 2012. With this as a base, SIGMA has given careful thought to the quality of a product, the feeling of using it and the pleasure of owning it. This is how the I series was born.

Exceptional I series build quality in an ultra-compact body

Sigma is now one of the very few imaging manufacturers whose products are solely made in Japan. This gives us full control over our production processes and helps us maintain the highest levels of quality control over the design, manufacture and construction of every product. Great care is taken to ensure the highest quality materials are chosen.

All I series lenses are designed with an all-metal barrel. The precision-cut aluminium parts not only give the lens a sleek, stylish finish but provide superb durability, which improves the quality of the entire product. Metal materials are also used in internal structures that slide with the operation ring for added robustness. These high-precision components, crafted with Sigma’s cutting-edge metalworking technology, are also used in the production of the cine lens line-up for professional film-makers.

The lens has an aperture ring so that users can change aperture using either the lens or the camera. Great attention was paid to ensure the click is well-define but not too sharp. Sound-deadening grease has been used to create a more rounded sound. Similarly the metal focus ring is perfectly weighted for a precise and smooth action to ensure accurate manual focus control.

Remarkably, the 20mm F2 DG DN | C is almost identical in size and weight to the 24mm F2 DG DN | C, despite having a considerably wider angle-of-view (see image). The two lenses join other F2 optics in the I series range, such as the 35mm and 65mm, to make a perfect primes set.

Magnetic metal lens cap and metal lens hood

The 20mm F2 DG DN | C comes with a carefully machined metal lens hood, a feature not even found on Sigma’s Art series lenses. A large number of grooves called ‘knurling’ are cut in, improving the lens operation by serving as slip resistance and giving the lens a premium look and feel unique to the I Series. A specially chosen plastic was used for the part that connects to the lens to ensure smooth operation.

Included in the box is the regular Sigma plastic lens cap as well as an all-metal magnetic cap (pictured left), which snaps firmly on to the end of the lens. With no requirement for a spring-loaded clasp, the cap has a sleek, minimal finish.

Optional magnetic lens cap holder with carabiner

Available to buy separately is a new lens cap holder, onto which the magnetic metal lens cap can be quickly and easily attached when the lens is in use. This keeps the cap within easy reach and makes it less likely to get lost. Plus, its elegant design is a stylish addition to a photographer’s equipment.

The holder comes with a carabiner so that it can be attached to clothing or a bag strap.

Other features

  • 1Lens construction: 13 elements in 11 groups, with 1 FLD, 1 SLD element and 3 aspherical elements
  • Compatible with high-speed autofocus
  • Stepping motor
  • Aperture ring
  • Compatible with lens-based optical correction (supported cameras only. Corrections may vary)
  • Mount with dust- and splash-proof structure
  • Super Multi-Layer Coating
  • Nano Porous Coating
  • Focus Mode Switch
  • Petal Type Lens Hood (LH656-03)
  • Compatible with SIGMA USB DOCK UD-11 (sold separately / for L-Mount only)
  • Designed to minimise flare and ghosting
  • Supports DMF, AF+MF (for Sony E-mount only)
  • Inner focusing
  • Every single lens undergoes SIGMA’s proprietary MTF measuring system ‘A1’
  • 9-blade rounded diaphragm
  • High-precision, durable brass bayonet mount
  • ‘Made in Japan’ craftsmanship


You'll find our philosophy and craftsmanship in every product

Our new lineup fully expresses our approach to lenses and photography itself. All of our lenses belong to one of three lines—Contemporary, Art, or Sports—all of which share our development philosophy and advanced manufacturing system. High performance, high quality, and high end in every respect, these lenses give people who love photography lasting value and consistent, exciting results. The secret is our passion for craftsmanship that we put into every production process and every product.

Evaluation with Sigma's own MTF measuring system “A1”

We used to measure lens performance with MTF measuring system using conventional sensors. However, we’ve now developed our own proprietary MTF (modulation transfer function) measuring system (A1) using 46-megapixel Foveon direct image sensors. Even previously undetectable high-frequency details are now within the scope of our quality control inspections. The SIGMA 50mm F1.4 DG HSM will all be checked using this “A1” before they are shipped.

* A1: Aizu1

“Made in Japan”

All Sigma’s manufacturing – right down to moulds and parts – with a few exceptions, are carried out under a single integrated production system, entirely in Japan. We are now one of the very few manufacturers whose products are solely “made in Japan”. We like to think our products are somehow imbued with the essence of our homeland, blessed as it is with clean air and water, and focused, hard-working people. We pride ourselves on the authentic quality of Sigma products, born of a marriage between highly attuned expertise and intelligent, advanced technology. Our sophisticated products have satisfied professionals and lovers of photography all over the world because our manufacturing is based on genuine craftsmanship, underpinned by the passion and pride of our experts.

Applicable for the Mount Conversion Service

As an experienced lens manufacturer that has been creating a diverse range of interchangeable lenses, we have started the innovative chargeable service “Mount Conversion Service”. With this service, the mount of your current SIGMA lenses can be changed to another mount of your choice. It gives a new life to your favourite lenses when you wish to use it on a different camera body.

* This “Mount Conversion Service” is different from a normal repair. In order to apply for the service, please contact your nearest authorized subsidiary/distributor of SIGMA.

Outstanding wide-angle performance in an ultra-compact body

Lens construction



20mm F2 DG DN

Lens Construction 13 elements in 11 groups
Angle of View (35mm) 94.5 degrees
Number of Diaphragm Blades 9 Blades (Rounded diaphragm)
Minimum Aperture F22
Minimum Focusing Distance 22cm
Maximum Magnification 1:6.7
Filter Size Diameter 62mm
Dimensions Diameter 70mm x 72.4mm
Weight 370g

Corresponding AF Mounts

Barcode No.

L-Mount 00-85126-490969
Sony E-mount 00-85126-490965

Outstanding wide-angle performance in an ultra-compact body

Diffraction and Geometrical MTF Chart - 20mm F2 DG DN

Outstanding wide-angle performance in an ultra-compact body


Sigma Lens Cap

Front Lens Cap

Protect the front element of your lens with a SIGMA Rear Lens Cap. Helps to prevent dust, scratches and unwanted damage. Supplied with new SIGMA Global Vision lenses* *Excluding some lens variants.

Item No.


Lens Hood LH656-03

Lens Hood for 20mm F2 DG DN | C (LH656-03)

The Lens Hood LH656-03 is designed specifically for the SIGMA 20mm F2 DG DN | Contemporary. The hood will help protect the front element of the lens whilst also blocking any unwanted light from entering the lens. The knurled surface of the metal hood helps prevent your fingers slipping when attaching and removing the hood. …

Item No. 490H01


Magnetic metal lens cap FRONT CAP LCF62-01M (62MM I series)

The SIGMA I series features full-frame compatible lenses that offer new value to mirrorless systems. It is the dedicated magnetic metal lens cap crafted without any compromise that completes the concept of the I series, which embodies the quality of the products, the feeling of using it and the pleasure of owning it. In order …

Item No. A00262


Lens Cap Holder CH-11

Magnetic metal lens cap holder SIGMA LENS CAP HOLDER CH-11

The magnetic metal cap holder LENS CAP HOLDER CH-11 (sold separately) allows you attach the cap to the strap of your belt or a bag for carrying around hands free. Push your finger through the donut-shaped hole when you remove the cap from the cap holder. Lens cap supplied separately.      

Item No. AN2900


Rear Lens Cap

Protect the rear elements of your lens with a SIGMA Rear Lens Cap. Helps to prevent dust, scratches and unwanted damage to the lens contacts. Supplied with new SIGMA Global Vision lenses* *Excluding some lens variants.

Item No.


Sigma USB Dock UD-11

Designed exclusively for the use with a SIGMA Contemporary, Art, or Sports lens and its accessories, the SIGMA USB DOCK allows users to update firmware and customize settings on lenses in these lineups. As the latest addition to the lineup, the USB DOCK UD-11 is designed for two types of mirrorless camera mounts: the L-Mount …

Item No.