An Art level 20mm F1.4.
The ultimate lens for astrophotography.

Outstanding optical quality and a range of invaluable features –
The ultimate astrophotography lens from the 20mm F1.4 pioneer

The F1.4 series represents the SIGMA Art line, which pursues the highest optical performance and rich expression. The full-frame SIGMA 20mm F1.4 DG DN | Art is a mirrorless version of the SIGMA 20mm F1.4 DG HSM | Art; the one and only lens* with its unique specification of maximum aperture of 1.4 and an ultra-wide angle of 20mm. This lens offers photographers overwhelming optical performance and unlimited potential for ultra wide-angle creativity at a compact physical size. The exceptional F1.4 brightness and the breathtaking sharpness across the entire image even at maximum aperture make this lens the ultimate choice for astrophotography. In nightly darkness and focused to infinity, the 20mm F1.4 DG DN | Art captures stars in the sky as clear, precise pinpoints of light. State-of-the-art optical design and the large, high-precision double-sided aspheric glass front element made it possible to add a front filter thread without any compromises regarding optical performance or size. The addition of other invaluable features such as a rear filter holder and a variety of useful switches further increases the creative possibilities and easy usability of the lens. Its incredible sharpness and very bright aperture, coupled with the compact body and thoughtful features, make the SIGMA 20mm F1.4 DG DN | Art the ultimate lens for astrophotography and an ideal companion for any photographically demanding situation.

  • * As an AF interchangeable lens for mirrorless cameras that covers 35mm full-frame (As of August 2022, by SIGMA)


©Jack Fusco

©Tony Noël

©Dean Sherwood

©Shigemi Numazawa


Highest optical performance on a new level

The SIGMA 20mm F1.4 DG DN | Art delivers exceptionally detailed results that easily satisfy the high demands of professional photography and other high-end applications. With 17 glass elements arranged in 15 groups, including two SLD, three aspherical glass elements and the largest class double-sided aspherical glass element in SIGMA’s history, the 20mm F1.4 DG DN | Art rigorously suppresses various optical aberrations such as sagittal coma flare or image distortion to produce highly-detailed images with exceptional sharpness and accuracy from the center to the furthest corners, allowing photographers to make use of the entire field of view afforded by its ultra-wide viewing angle. This ultimate astrophotography lens is the culmination of the unparalleled manufacturing technology of SIGMA’s sole production base in Aizu, Japan, as well as the company’s know-how and experience with large-aperture wide-angle lenses, such as the SIGMA 20mm F1.4 DG HSM | Art, the SIGMA 14mm F1.8 DG HSM | Art and the SIGMA 14-24mm F2.8 DG DN | Art.

The largest class double-sided aspherical glass element

Designed for perfect results even in the most demanding conditions

The new MFL (Manual Focus Lock) switch

When the MFL switch is set to “LOCK”, the focus ring operation will be disabled.
This is to prevent the focus ring from accidentally being moved, which would cause out-of-focus images.

Support front and rear filters

The lens also comes with a rear filter holder, allowing photographers the freedom to combine multiple filters to suit a huge variety of shooting situations for near-unlimited creative potential at an ultra-wide viewing angle—for example, using a front filter to reduce light pollution and a softening filter on the rear to take impressive, sharp photographs of nightly landscapes with star-filled skies.

Lens heater retainer

Further, the lens also equips a lens heater retainer, meaning that lens heaters used to prevent internal condensation as the temperature drops on longer night shoots will stay securely attached to the barrel without protruding into the image and causing unsightly vignetting. With its brilliant optical power and its full range of useful features despite its compact and lightweight body, the SIGMA 20mm F1.4 DG DN | Art is the ultimate choice when photographing the night sky.

Superb build quality and usability with uncompromising attention to detail

Its dust- and splash-resistant structure* and the water- and oil-repellent coating on the front glass element make the SIGMA 20mm F1.4 DG DN | Art safe to use during longer outdoor shoots, especially during the night.

  • * Although this construction allows the lens to be used in light rain, it is not the same as being waterproof.

1 Focus mode switch
2 AFL button
3 MFL (Manual Focus Lock) switch
4 Aperture ring click switch

5 Lock mechanism
6 Aperture ring lock switch

Thoughtful features such as a focus mode switch, a customizable AFL* button, and an aperture ring lock switch enhance the lens usability. An aperture ring click switch can be used to turn the aperture ring click on and off, allowing photographers to enjoy the sound and feel of the click, as well as smooth aperture operation during video recording.
The robust body is built from a combination of aluminum and Thermally Stable Composite (TSC), giving it a sleek finish, and the included petal-shaped lens hood is equipped with a lock mechanism to keep the hood securely fastened to the lens, and the rubberized grip area makes attaching and removing the hood a quick and easy process. Manufactured in Japan with an uncompromising approach towards every single detail, the SIGMA 20mm F1.4 DG DN | Art offers photographers an exceptional experience with high-end results even in the most difficult conditions, thanks to its outstanding optical performance, exceptional build quality perfect for professional use, brilliant and precise ergonomics, and a range of useful features.

  • * Only on compatible cameras. Available functions may vary depending on the camera used.

Additional features

Lens construction: 17 elements in 15 groups

Inner focus system

Compatible with high-speed autofocus

Stepping Motor

Compatible with front filter (φ82mm)

Compatible with Lens Aberration Correction

*Function available on supported cameras only. Available corrections or auto correction functionality may vary depending on the camera model.
*On cameras where lens aberration correction is controlled with ‘ON’ or ‘OFF’ in the camera menu, please set all aberration correction functions to ‘ON'(AUTO).

Support for DMF and AF+MF

Compatible with AF Assist (Sony E-mount only)

Super Multi-Layer Coating

Water- and oil-repellent coating

Aperture ring

Aperture ring click switch

Aperture ring lock switch

AFL button

MFL switch

Rear Filter Holder

Lens Heater Retainer

Focus Mode switch

Support for switching between linear and non-linear focus ring settings (L-Mount only)

Petal-type LENS HOOD (LH878-04)

Dust and Splash Resistant Structure

Compatible with SIGMA USB DOCK UD-11 (sold separately; L-Mount only)

Designed to minimize flare and ghosting

Every single lens is evaluated with SIGMA’s proprietary MTF measuring system

11-blade rounded diaphragm

High-precision, durable brass bayonet mount


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—Art, Contemporary, 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.


20mm F1.4 DG DN | Art

Lens Construction

  • SLD glass

Lens Construction

17 elements in 15 groups

Angle of View

  • 94.5 °

Number of Diaphragm Blades

11 (Rounded diaphragm)

Minimum Aperture


Minimum Focusing Distance

23cm / 9.1in.

Maximum Magnification Ratio


Filter size


Dimensions (Diameter × Length)

  • L-Mount
    φ87.8mm × 111.2mm / φ3.5in. × 4.4in.
  • Sony E-Mount
    φ87.8mm × 113.2mm / φ3.5in. × 4.5in.


  • L-Mount
    635g / 22.4oz.
  • Sony E-Mount
    630g / 22.2oz.

Edition Number


Supplied Accessories

・Petal-type LENS HOOD LH878-04

Corresponding AF Mounts / Barcode No.

  • L-Mount
  • Sony E-Mount


  • Lens Heater Retainer

    The Lens Heater Retainer is a protruding lip at the front of the lens. When the…

  • Rear filter holder

    The rear filter holder allows the attachment of a sheet-type filter to the rear…

  • MFL switch

    The MFL (Manual Focus Lock) switch disengages the focus ring on the lens. After…

Performance / Data

MTF Chart

Diffraction MTF

Geometrical MTF

Product Lineup

20mm F1.4 DG DN | Art

  • L-Mount

    Supplied Accessories

    ・Petal-type LENS HOOD LH878-04

    Barcode No.
  • Sony E-mount

    Supplied Accessories

    ・Petal-type LENS HOOD LH878-04

    Barcode No.


Supplied Accessories


Barcode No.


* The image is for SIGMA.

  • L-Mount

    Barcode No.
  • Sony E-mount

    Barcode No.


Barcode No.

Separately Sold Accessories


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 adjust the sensitivity of speed to the MF function* through the UD-11.
* Scope of adjustment varies depending on specifications of the individual product.

  • L-Mount

    Barcode No.


Water-repellent, Antistatic type. Protector is developed to protect the lens surface from dirt and dust as well as scratches. It is an ideal filter for regular use as it is completely colorless so does not affect color reproduction.

* Thinner frame wide type.

Barcode No.


Normal type. Protector is developed to protect the lens surface from dirt and dust as well as scratches. It is an ideal filter for regular use as it is completely colorless so does not affect color reproduction.

* Thinner frame wide type.

Barcode No.


UV Water-repellent, Antistatic type. UV filter prevents the bluish tone that generates when the weather is fine, by absorbing ultraviolet rays. It is effective in most situations, such as landscape, portrait and general photography on a sunny day. It is also an ideal filter for regular use as it is completely colorless so does not affect color reproduction.

* Thinner frame wide type.

Barcode No.


PL Water-repellent, Antistatic type. Circular PL filter removes the reflection of water surface and glass windows, and increases the contrast in landscape photography.

* Thinner frame wide type.

Barcode No.

Catalogs / Resources

Manuals / Brochures

Impressions / Samples