When it comes to ultra-wide-angle lenses, photographers require outstanding image quality from the center of the image to the edges without any distortion. Such performance is particularly valuable in architectural photography. The new SIGMA 12-24mm F4 DG HSM | Art leverages SIGMA’s accumulated expertise in the processing and manufacture of aspherical lenses and incorporates multiple aspherical lenses produced with precision glass molding. The lens also features lens elements made with FLD (“F” Low Dispersion) glass, which is equivalent to fluorite in performance, and an optimized power distribution. Together, these features help minimize distortion, transverse chromatic aberration, and coma flare. As a result, image quality is outstanding across the image, all the way to the edges.

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.

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.

To deliver amazing image quality, SIGMA has added in all its latest technologies, starting with the mechanical system. The optical system features an ⌀80mm diameter aspherical lens element, which is the largest for this lens class on the market. By leveraging all of its development experience to date, SIGMA has established a new era of 12-24mm performance.

The SIGMA 12-24mm F4 DG HSM |Art features an ⌀80mm large-diameter molded glass aspherical lens—the largest such element in this class of lens. This lens is highly effective in minimizing distortion, spherical aberration, and coma flare.

The newly designed Hyper Sonic Motor (HSM) is large, offers 1.3 times the torque of its predecessor. Even at low speeds, it offers exceptionally stable performance.

Leveraging the incredibly broad perspective of an ultra-wide-angle lens, photographers can compose close-up shots with impressively expansive backgrounds.

* At 24mm end of the zoom range

With F4 throughout the zoom range, this lens is one stop brighter than conventional lenses. Photographers can now use a higher shutter speed that will crisply capture leaves fluttering in the breeze and other quick-moving subjects. A constant aperture during zooming also makes this lens exceptionally easy to use.

The lens mount incorporates rubber sealing to protect the mount from dust and water drops. The front and rear lenses feature a water- and oil-repellent coating that is particularly useful when shooting in a drizzle, near ocean spray, and in a wide variety of other conditions.

The lens for the Nikon camera includes the electromagnetic diaphragm mechanism and is able to receive the appropriate signals from the camera body. This feature ensures precision diaphragm control and stable Auto Exposure (AE) performance during continuous shooting.

To ensure precise operation, internal parts feature generous use of metal and Thermally Stable Composite (TSC),* which is highly compatible with metal parts.

* TSC offers thermal expansion characteristics similar to those of aluminum. Parts made with TSC deform less, making lens construction of extremely high precision possible. As compared to polycarbonate containing 20% glass, a commonly used material, TSC offers approximately 70% higher elasticity. As compared to polycarbonate containing 30% glass, it offers 25% higher elasticity. (Comparison is between SIGMA-produced components.)

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

The newly designed Hyper Sonic Motor (HSM) is large, offers 1.3 times the torque of its predecessor. Even at low speeds, it offers exceptionally stable performance.

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

Mount Converter MC-11 allows you to use your SIGMA SA mount and SIGMA EOS mount (Canon-compatible) interchangeable lenses with the Sony E-mount camera body. Owners of multiple camera systems can now get even more out of their valuable lens assets.

We used to measure lens performance with a Modulation Transfer Function (MTF) measuring system using conventional sensors. However, we have developed our own proprietary MTF measuring system (A1)* using 46-megapixel Foveon direct image sensors. Even previously undetectable high-frequency details are now within the scope of our quality control inspections. All SIGMA 12-24mm F4 DG HSM | Art lenses are checked using this A1 system before they are shipped.

*A1：Aizu１

The 46 effective megapixel (4,800 × 3,200 × 3 layers) and 44 recording megapixel (4,704 × 3,136 × 3 layers) 23.5 × 15.7mm APS-C X3 direct image sensor captures all primary RGB colors at each and every pixel location, ensuring the capture of full and complete color. Using three silicon-embedded layers of photo detectors, stacked vertically to take advantage of silicon’s ability to absorb red, green and blue light at different respective depths, it efficiently reproduces color more accurately, and offers sharper resolution, pixel for pixel, than any conventional image sensor. Since color moiré is not generated, the use of a low-pass filter is not required, meaning light and color, generated by the 46-megapixel APS-C X3 direct image sensor is captured with a three-dimensional feel.

With only a few minor exceptions, all of SIGMA’s manufacturing, including molds and parts, takes place under a single integrated production system in Japan. We are now one of the very few manufacturers whose products are truly made in Japan. We like to think our products are somehow imbued with the essence of our homeland, blessed as it is with clean air and water, and focused, hard-working people. We pride ourselves on the authentic quality of SIGMA products, born of a marriage between highly attuned expertise and intelligent, advanced technology. Our sophisticated products have satisfied professionals and lovers of photography all over the world because our manufacturing is based on genuine craftsmanship, underpinned by the passion and pride of our experts.

With the optional SIGMA USB DOCK, you can update your lens firmware and adjust the focus position and other settings. Simply connect the lens to the SIGMA USB DOCK and the dock to a computer to use the dedicated SIGMA Optimization Pro software and perform various types of customization and adjustment.

Over the years, SIGMA has manufactured an extremely wide variety of interchangeable lenses. Leveraging our unique know-how and resources, we present our new Mount Conversion Service, which will be available for the SIGMA 12-24mm F4 DG HSM | Art and other SIGMA interchangeable lenses SIGMA will convert the current lens mount internal components, allowing you to continue using your favorite SIGMA lenses from the new product lines with a different camera body. Thanks to this service, you can use a favorite lens for many years to come, unrestricted by your original choice of camera system.

Note: SIGMA’s mount conversion service differs from ordinary repairs and product support and is not offered at your local SIGMA dealer or camera store. To access this service, please communicate directly with SIGMA.