Sigma 20mm f1.4 DG DN A – L Mount

Overview
The SIGMA 20mm F1.4 DG DN | Art lens boasts a construction of 17 elements in 15 groups, including 2 FLD and 3 aspherical elements. It also features an internal focus system and is compatible with high-speed autofocus. The lens is equipped with a stepping motor and is compatible with Lens Aberration Correction, although this function may vary depending on the camera model. On cameras where lens aberration correction is controlled with ON or OFF in the camera menu, it is recommended to set all aberration correction functions to ON (AUTO).

The lens also offers a range of advanced features such as support for DMF and AF+MF, AF Assist (Sony E-mount only), Super Multi-Layer Coating, Nano Porous Coating, and a water- and oil-repellent coating. It also has a focus mode switch, aperture ring, aperture ring de-click switch, aperture ring lock switch, AFL button, MFL switch, rear filter holder, petal-type lens hood, and a mount with a dust and splash-resistant structure. Additionally, the lens is designed to minimize flare and ghosting, has a 9-blade rounded diaphragm, and a high-precision, durable brass bayonet mount. It is also compatible with the SIGMA USB DOCK UD-11 (sold separately; L-Mount only) and is evaluated with Sigmas proprietary MTF measuring system.

The SIGMA 20mm F1.4 DG DN | Art is a versatile and high-performance wide-angle lens that is perfect for astrophotography, landscapes, interiors, and other wide-angle applications. Weighing only 635g, it is significantly lighter and more portable than Sigmas previous 20mm F1.4 lens. The lens delivers exceptional optical performance with ultra-sharp results across the entire frame, even at F1.4. Its advanced features, compact form-factor, and beautiful construction make it a must-have for photographers looking to unleash their creative potential and capture stunning wide-angle images.

Summary
Focal Length: 20mm
Max Aperture: f/1.4
Lens Type: Wide
Lens Mount: L Mount
Weight: 0-2kg
Included in box
Sigma AF 20mm F1.4 DG DN Art – L Mount
Case
Petal-type lens hood with lock (LH878-04)
Front Cap (LCF-82 III), Rear Cap(LCR II)
Filter Holder
Guide Plate (GP-21)

About the Sigma 20mm f1.4 DG DN A – L Mount
The SIGMA 20mm F1.4 DG DN | Art is a wide-angle, ultra-wide-aperture prime that is perfect for astrophotography. Available in L-Mount and Sony E-mount, it delivers outstanding Art-line optical quality and offers a range of advanced features. As well as being very well-suited to astro, the 20mm F1.4 is an ideal optic for landscapes, interiors and a range of other wide-angle applications

Weighing in at just 635g, the lens is significantly lighter and more portable than Sigma’s existing 20mm F1.4,and introduces a number of important features including a manual aperture ring with de-click and lock functionality, a front filter thread and rear filter holder, a Lens Heater Retainer to hold a heat strip in position,and an all-new Manual Focus Lock switch to fully deactivate the focus ring.

The optical performance of the lens is exceptional, with ultra-sharp results across the entire frame even at F1.4, and very well controlled sagittal coma flare – essential for astrophotography. The brightaperture is perfect for night sky landscapes, as well as for hand-heldlow-light shooting and for achieving a shallow depth-of-field.

This superb image quality, compact form-factor and advancedfeature-set, combined with a beautifully constructed body,make for a versatile, high-performance optic that will enablephotographers to unleash their creative potential and startachieving wide-angle images with impact.* Figures are for L-Mount

Outstanding optical performance

The SIGMA 20mm F1.4 DG DN | Art delivers highly detailed results that easily satisfy the demands of professional photographers and film-makers.

The lens is constructed with 17 elements arranged in 14 groups, including two SLD elements and three aspherical elements, one of which is the largest double-sided aspherical element ever produced by Sigma. This advanced optical design rigorously suppresses a rangeof optical aberrations, such as sagittal coma flare and chromatic aberration, and ensures pin-sharpresults right across the frame even wide-open at F1.4.

The outstanding performance of this all-new wide-angle prime has been made possible thanks to Sigma’sunparalleled manufacturing technology at its sole production base at Aizu in Japan, which has evolved over 60years of lens development. The company pioneered the world’s first full-frame 20mm F1.4 prime in 2015, andhas since produced some of the highest-performing wide-angle primes and zooms on the market, including the 14mm F1.8 DG HSM | Art and the 14-24mm F2.8 DG DN | Art.

Advanced functionality for every shooting situation

SIGMA’s experience in optical design, combined with its high-precision manufacturing capability, has made it possible to equip the 20mm F1.4 DG DN | Art with a front filter thread in spite of its very large F1.4 aperture andultra-wide angle-of-view. The lens also comes with a rear filter holder, giving photographers the freedom to more easily combine multiple filters. This is particularly useful for astrophotographers, who may want to attacha light pollution filter at the front and a soft filter at the rear.

The lens has an aperture ring built in, which is de-clickable for a smooth transition between aperture settings– useful for changing exposure seamlessly during video shooting. The aperture ring also has a lock switch. A new Manual Focus Lock (MFL) switch completely deactivates the focus ring, ensuring the focus position won’t change if it is accidentally knocked. So for night-sky photographers, the days of using tape the hold the focusring in position are over.

Another brand new feature designed with astrophotographers in mind is the Lens Heater Retainer, which is a pronounced lip around the front element to keep a heat strip firmly in place. Heat strips are commonly used tostop condensation forming on the elements when working at night.

An AFL button is built into the lens, which can be customized *1 to a range of different functions
*1 Only on compatible cameras. Available functions may vary depending on the camera used

Superb build quality with uncompromising attention to detail

Designed and manufactured at Sigma’s sole factory in Aizuin Japan, the 20mm F1.4 DG DN meets the exceptionally highproduction standards that users have come to expect from Sigma’s Global Vision lenses.

The robust body is built from a combination of aluminium and Thermally Stable Composite (TSC), giving it a sleek finish, and the focus ring has a smooth, well damped action. A petal-shaped lens hood is included, and equipped with a lock mechanism to keep it securely fastened to the lens. A rubber grip makes it easier to attach and remove the hood.

Built with a dust and splash-resistant structure, a water- and oil-repellent coating on the front element, and a rubber seal around the mount, the 20mm F1.4 DG DN is safe to use during longer outdoor shoots.*2

The 20mm F1.4 DG DN is built with exceptional attention to detail in its functionality, construction and design ergonomics, helping users achieve the best possible results in any shooting situation.

*2 While the lens is safe to use in light rain, please note that it is not fully weather sealed and therefore not waterproof

Lens construction: 15 groups, 17 elements (2 FLD and 3 aspherical elements)
Angle-of-view: 94.5°
Number of diaphragm blades: 11 (rounded diaphragm)
Minimum aperture: F16
Minimum focusing distance: 23cm
Maximum magnification ratio: 1:6.1
Filter size: φ82mm
Dimensions (max diameter x length): φ87.8mm x 111.2mm
Weight: 635g

Lens construction: 17 elements in 15 groups, with 2 FLD and 3 aspherical elements
Internal focus system
Compatible with high-speed autofocus
Stepping Motor
Compatible with Lens Aberration Correction
Function available on supported cameras only. Available corrections and 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
Nano Porous Coating
Water- and oil-repellent coating
Focus Mode Switch
Lens Heater Retainer
Aperture Ring
Aperture Ring De-click Switch
Aperture Ring Lock Switch
AFL Button
MFL Switch
Rear filter holder
Petal-type lens hood (LH878-04)
Mount with dust and splash-resistant structure
Support for switching between linear and non-linear focus ring settings (L-Mount only)
Compatible with SIGMA USB DOCK UD-11 (sold separately; L-Mount only)
Designed to minimise flare and ghosting
9-blade rounded diaphragm
High-precision, durable brass bayonet mount
‘Made in Japan’ craftsmanship
Every single lens is evaluated with Sigma’s proprietary MTF measuring system