Sigma 28-45mm F1.8 DG DN | Art lens for L-Mount 

The ultimate fast-aperture hybrid zoom for both stills and video

The SIGMA 28-45mm F1.8 DG DN | Art is a full-frame zoom lens with a constant maximum aperture of F1.8, delivering sharpness and clarity comparable to that of a prime lens.

In addition to its unprecedented brightness, the SIGMA 28-45mm F1.8 DG DN | Art delivers sharpness and clarity comparable to that of a prime lens throughout its entire zoom range. Also equipped with fast and precise AF and superior operability, this innovative optic turns a new page in the history of zoom lenses and their creative possibilities. It is a lens that will inspire full-frame film-makers, while bringing unparalleled versatility to stills photographers.

The lens’ fast F1.8 aperture allows full-frame camera users to expose hand-held in low light and produce beautiful bokeh, while enjoying the flexibility of a zoom. This unique optical achievement has been created through SIGMA’s accumulated optical design experience and advanced production technology at the company’s sole production base in Aizu, Japan. 

The 28-45mm is particularly well-suited for video thanks to its controlled focus breathing, internal zoom and ultra-smooth HLA focus motor.

Outstanding build quality

By rights, such a fast zoom should be big and heavy, but while the lens’s rigidity and durability protect its sophisticated optical design, this is achieved at a weight of less than 1kg. What’s more, this reliable photographic tool uses a versatile filter size of φ82mm, meaning no compromise in portability or convenience.

Towards the rear of the barrel is an aperture ring, which can be de-clicked for stepless aperture changes. When put into Auto, aperture is controlled by the camera. A lock switch allows users to lock the ring in Auto or Manual so it’s not accidentally knocked into a different setting.

To reduce flare and ghosting in bright sun, and to help protect the front element from damage if dropped, the lens has a robust petal-type lens hood with lock button. A rubberised ring on the hood makes for easier removal and fitting.

The durable brass mount is surrounded by a rubber seal to help keep out dust and moisture, and there are weather resistant seals throughout the lens body.

• Precision brass mount with seal: Protects against dust and moisture.
• Aperture ring: With a click/de-click switch and a lock switch.
• Zoom ring: A large, rubberised ring with a smooth action. The zoom is internal.
• Focus ring: A large, rubberised ring with a smooth action. Focusing is internal.
• Petal-type lens hood: Lockable hood that cuts down on flare while limiting vignetting.
• Focus Mode switch: For changing between AF and MF.
• AFL button: Customisable depending on camera body.
• Aperture Click switch: Clicks or de-clicks the aperture ring.
• TSC construction: Made from a strong and light polycarbonate that behaves in a similar way to aluminium.

Professional feature-set

A range of controls on the lens include an AF/MF switch, two customisable AFL switches, and switches to de-click and lock the aperture ring.

The lens is constructed from Thermally Stable Composite, a strong and light polymer that has a similar thermal expansion rate to the interior aluminium parts. This ensure that the lens behaves in a uniform and reliable way regardless of the temperature.

HLA focusing motor

The 28-45mm F1.8 DG DN | Art uses SIGMA’s High-response Linear Actuator motor to control the focus group of lens elements. More powerful than a stepping motor, it ensures extremely rapid AF. It’s also very accurate and near-silent, and works perfectly with focus tracking systems.

The other advantage the powerful HLA motor brings with it is that it can move larger and heavier focusing groups than a stepping motor, which unlocks the door more advanced optical designs, and therefore sharper results.

The pinnacle of optical quality in a zoom

With each optical aberration meticulously corrected throughout the zoom range, the SIGMA 28-45mm F1.8 DG DN | Art rivals prime lenses for clarity and definition. Thanks to its advanced coatings, the lens produces clear images, even in backlit environments, while focus breathing is thoroughly suppressed, bringing expressive power to film-makers and photographers.

Through the effective arrangement of 5 SLD elements and 3 aspherical elements, aberrations are rigorously corrected. Axial chromatic aberration, which is particularly noticeable with large-aperture lenses, has been thoroughly suppressed, and the lens delivers clear images with minimal coloration, from sharply focused details to large, smooth bokeh.

Close-up shooting

The minimum focusing distance is a constant 30cm across the entire zoom range, with a maximum magnification ratio of 1:4 at the telephoto end, providing excellent close-up shooting capabilities. As well as offering precise focus in confined spaces, the lens can therefore be used close to a subject without affecting sharpness when using the zoom.

Rugged design for tough conditions

In addition to a dust- and splash-resistant body, which has rubber seals around the focus, zoom and aperture rings, as well as the buttons and switches, the frontmost surface of the lens is coated with a water- and oil-repellent coating so that it can be used safely even in harsh outdoor environments.

Ideal for gimbal use

Employing an inner zoom mechanism, the overall length of the lens remains constant when the focal length or focus distance changes. This means the lens is easy to use when shooting hand-held, highly stable when mounted on a tripod or gimbal, and more resistant to dust and water contamination.

Made in Aizu, Japan

All Sigma cameras and lenses are designed, manufactured and assembled at our sole factory at Aizu in Japan. This domestic production model is unusual in today’s industry, with most imaging companies opting to outsource to other countries to reduce costs. But SIGMA believes that keeping virtually all manufacturing, processing and assembly in Aizu is essential for creating innovative, carefully thought-out and impeccably constructed products that meet the high standards demanded by professional photographers and film-makers around the world.