Art
20mm F1.4 DG HSM

• Camera Type

  DSLR

• Corresponding Mount

  L-Mount, Sony E-mount, SIGMA SA-mount, Canon EF mount, Nikon F mount

• Sensor Format

  Full-frame [DG]

• Lens Construction

  15 elements in 11 groups

• Angle of View

  94.5°

• Number of Diaphragm Blades

  9 (Rounded diaphragm)

• Minimum Aperture

  F16

• Minimum Focusing Distance

  27.6 cm / 10.9 in.

• Maximum Magnification Ratio

  1:7.1

• Dimensions (Diameter × Length)

  SIGMA SA-mount：φ90.7mm × 129.8mm / φ3.6in. × 5.1in.

  Sony E-mount：φ90.7mm × 155.8mm / φ3.6in. × 6.1in.

  L-Mount：φ90.7mm × 153.75mm / φ3.5in. × 6in.

  *The length of a lens is measured from the filter surface to its mount.

• Weight

  SIGMA SA-mount：950g / 33.5oz.

  Sony E-mount：1,015g / 35.8oz.

  L-Mount：1,035g / 36.5oz.

• Edition Number

  A015

  The three-digit code on the surface of the lens is to indicate the year the lens was first released.
  (Since it is different from the year of manufacture, the release year and edition number may not match depending on the mount.)

• Supplied Accessories

  ・Case
  ・COVER LENS CAP LC907-01
  ・REAR CAP LCR II

• Mount / Product Barcode

  SIGMA SA-mount：00-85126-41256-2

  Nikon F mount：00-85126-41255-5

  Canon EF mount：00-85126-41254-8 (discontinued)

  Sony E-mount：00-85126-41265-4

  L-Mount：00-85126-41269-2

• Camera Compatibility

  LINK

• * This product is developed, manufactured and sold based on the specifications of E-mount which was disclosed by Sony Corporation under the license agreement with Sony Corporation.
  * L-Mount is a registered trademark of Leica Camera AG.

• Advanced technologies makea 20mm F1.4 lens possible

  World’s first 20mm F1.4 lens —thanks to advanced large-diameter aspherical lens manufacturing technologies

  To offer an ultra-wide-angle 20mm focal length and F1.4 brightness at wide-open aperture, this lens incorporates a large double aspherical lens 59mm in diameter. Lenses of this type had been considered extremely difficult to manufacture, but Sigma took on the challenge to realize an F1.4 ultra-wide-angle lens that fulfills the strict performance requirements of the Sigma Art line. What made this breakthrough possible were Sigma’s advanced manufacturing technologies, which the company has developed over time by producing a wide range of ultra-wide-angle and large-aperture lenses. For example, milestone lenses such as Sigma 12-24mm F4.5-5.6 EX DG ASPHERICAL HSM, Sigma 8-16mm F4.5-5.6 DC HSM, and Sigma 18-35mm F1.8 DC HSM | Art were completely original products that helped Sigma develop outstanding design and production know-how and its current high-precision, high-efficiency production system. In turn, these advances made possible the new Sigma 20mm F1.4 DG HSM | Art. Moreover, Sigma’s advanced optical design minimizes distortion, transverse chromatic aberration, sagittal coma flare, and the reduction of brightness toward the edges of the image. Delivering top performance even at wide-open aperture, this lens can be considered the culmination of Sigma’s Art line.

  * Left side: The aspherical glass element incorporated in the Sigma 18-35mm F1.8 DC HSM | Art、Right side: The aspherical glass element incorporated in the Sigma 20mm F1.4 DG HSM | Art.

• Minimized chromatic aberrations

  This lens minimizes chromatic aberrations, a common issue in large-aperture ultra-wide-angle lenses. It features two
  (*)FLD (“F” Low Dispersion) glass and five SLD (Special Low Dispersion) glass elements to minimize transverse chromatic aberration, which is mainly visible around the edge of the image. The optimized lens power distribution helps minimize axial chromatic aberration. As a result, this lens delivers high image quality in every situation without color smearing, and its rendering performance is consistently sharp with high contrast.

  (*)FLD ("F" Low Dispersion) glass
  FLD glass is ultra-low-dispersion glass that offers performance of the highest level. Highly transparent, its refractive index and dispersion are extremely low as compared to conventional types of glass. It offers characteristics very similar to those of fluorite, which is valued for its anomalous dispersion. These characteristics minimize residual chromatic aberration (secondary spectrum), which cannot be corrected by ordinary optical glass, while helping to produce sharp, high-contrast images.

  

• Minimized distortion

  Distortion is a common issue in wide-angle lenses, and it is not possible to correct it simply by changing the aperture value. For this reason, a lens must be designed from the start to minimize this issue. By adjusting the incidence angle of light starting with the first lens element and incorporating optimally positioned aspherical glass elements, the Sigma 20mm F1.4 DG HSM | Art lens minimizes distortion throughout the entire image.

• Exclusive low-dispersion glass

  The degree to which light is refracted by glass depends on the light’s wavelength. This fact causes different colors of light to focus at slightly different points. The result is chromatic aberration, the color fringing that is particularly noticeable in telephoto lenses. Most chromatic aberration can be removed by combining a high-refractivity convex lens element with a low-refractivity concave element. Yet residual chromatic aberration known as “secondary spectrum” may still remain. To minimize this secondary spectrum, which can be a serious issue with conventional lenses, Sigma lenses feature up to three types of exclusive low-dispersion glass offering superior performance: ELD (Extraordinary Low Dispersion), SLD (Special Low Dispersion) and FLD (“F” Low Dispersion). In particular, FLD glass offers ultra-low dispersion in combination with high transmittance and the anomalous dispersion characteristics of fluorite. Meticulous deployment of these types of exclusive low-dispersion glass and optimization of power distribution gives Sigma lenses superlative image rendition undiminished by residual chromatic aberration.

  

• Flare and ghosting reduction

  From an early stage in the lens design process, flare and ghosting have been measured to establish an optical design resistant to strong incident light sources such as backlighting. Sigma’s Super Multi-Layer Coating reduces flare and ghosting to help photographers produce sharp and high contrast images even in backlit conditions.

  

• The ideal high-speed lens for snapshots and much more

  Top-level performance for the ultra-high-megapixel era

  At the dawn of the film camera, there was very little high-sensitivity film, and bright lenses that worked well in low-light conditions came to be known as “high-speed lenses.” These lenses are ideal for shooting indoors, in the evening, under cloudy skies, or in any low-light situation. Since the Sigma 20mm F1.4 DG HSM | Art provides the benefits of an ultra-wide angle lens with minimal distortion, it is ideal for photographing landscapes, starry skies, and architecture. In addition to capturing wide-angle shots with the whole scene in focus, the photographer can leverage wide-open aperture to take snapshots with the subject in focus and the background blurred with an attractive bokeh effect. Designed for ultra-high-megapixel digital cameras, this high-performance lens delivers outstanding resolution and high-clarity image quality even at wide-open aperture.

  

• The finest in materials, usability and functionality.

  A refined, integrated design made with the photographer in mind

  In our new product lines, the lens caps and AF/MF switches are newly designed to improve usability. To ensure precise operation, internal parts feature generous use of metal and (*)TSC (Thermally Stable Composite), which is highly compatible with metal parts. The lens barrel is engraved with the year of release for instant access to this information.

  (*)TSC (Thermally Stable Composite)
  TSC (Thermally Stable Composite) is a type of polycarbonate with a thermal expansion rate similar to that of aluminum. It has high affinity to metal parts which contributes to high quality product manufacturing.

  

• Hyper Sonic Motor ensures high AF speed

  The Hyper Sonic Motor (HSM) ensures silent, high-speed autofocusing, while the optimized AF algorithm helps realize even smoother AF performance. At any time during AF, users may access MF simply by rotating the focus ring. This feature makes faster focus adjustment possible, since there is no need to use the AF/MF focus mode switch. Also, the optional Sigma USB DOCK allows the user to set the lens to conventional full-time manual focus override.

  Note: The operation of full-time MF may vary based on mount type.

  

• Metal lens cap available (sold separately)

  Matching the high-quality finish of the lens exterior, optionally available metal lens cap LC907-02 will go on sale simultaneously with the lens. Featuring materials identical to those of the lens barrel, this metal lens cap establishes a new level of unity within Sigma’s new lens lines.

  

• Rounded diaphragm

  The 9-blade rounded diaphragm creates an attractive blur in the out-of-focus areas of the image.

  

• High-precision, rugged brass bayonet mount

  The brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens.

  

Lens construction

FLD glass

SLD glass

Aspherical lens

• Spatial frequency

  S:Sagittal Line

  M:Meridional Line

• 10lp/mm

• 30lp/mm

Diffraction MTF

Geometrical MTF

• F1.4

• F2.8

• F5.6