Combining an optical design with in-camera corrections that keep distortion under control, this lens offers an extremely well-controlled sagittal coma flare that yields pin-point stars from edge to edge. Additionally, a new Manual Focus Lock (MFL) switch disables the focus ring, ensuring that focus never changes, even after hours of shooting under chilly, dark skies. The lens has also been developed to accept 82mm front filters, a rarity on ultrawide primes, and another unique feature includes a rear filter holder, which accommodates sheet filters for various creative effects.

As part of the Art line within Sigma's Global Vision series, this lens is designed to achieve truly notable optical performance and is ideally suited for creative and artistic applications.

Prime wide-angle 20mm f/1.4 lens is designed for full-frame format Sony E-mount mirrorless cameras and can also be used with APS-C models where it provides a 30mm equivalent focal length.

Fast f/1.4 maximum aperture is well-suited for working in low-light conditions and provides greater control over the focus position when using shallow depth of field techniques.

Two SLD and three aspherical elements have been incorporated within the lens design to correct for chromatic aberrations throughout the entire focusing range and to ensure exceptional clarity and contrast. This optical design also helps to control distortion and limit vignetting.

Employs a concave double-sided aspherical element, which provides outstanding edge-to-edge sharpness and optical performance.

Optimized for astrophotography, the lens offers extremely well-controlled sagittal coma flare and limits ghosting.

A Super Multilayer Coating has been applied to lens elements to minimize lens flare while producing contrast-rich and color-neutral imagery, even in backlit conditions.

Inner focus system powered by precise STM stepping motor provides high-speed autofocus and near-silent operation.

Optimized for astrophotography, a new MFL (Manual Focus Lock) switch disables the focus ring, ensuring that focus never changes, even after hours of shooting under chilly, dark skies.

Aperture ring with click switch and lock switch prevents accidental aperture changes.

A rounded eleven-blade diaphragm helps to produce an attractive out-of-focus quality.

Petal-shaped lens hood helps to reduce lens flare when working in strong lighting conditions and offers some protection to the front element of the lens.

82mm front filter threads and rear filter holder for sheet-type filters.

Curved lip at the front of the lens keeps an optional lens heater from slipping in front of the lens.

Brass bayonet mount for ensured precision and durability.

Compatible with AF Assist function on select Sony E-Mount mirrorless cameras.