Generally it is ideal for a lens to have a high rendering performance from the maximum aperture throughout the entire image. For instance, sagittal coma flare, where the point light sources do not gather at one point and leaves a tail, is a typical flare that occurs especially with wide-angle lenses. The SIGMA 24mm F1.4 DG HSM | Art has an optimized power layout, positioning aspherical lens elements at the rear and adjusting the incidence angle of the light source, enabling high rendering performance even from the widest aperture. It is perfect for astronomical photography and shooting illuminations because of the reduced blur on the point light sources near the edge of the image.

One of the elements required to achieve high rendering performance is the correction of chromatic aberration. Particularly, for axial chromatic aberration that is hard to correct even during image processing, the lens development stage was vital in ensuring minimized distortion. The SIGMA 24mm F1.4 DG HSM | Art incorporates FLD (“F” Low Dispersion)* glass and SLD (Special Low Dispersion) glass elements to minimize chromatic aberration of magnification which is mainly visible around the edge of the image. Moreover the power layout ensures the correction of axial chromatic aberration. Without any color blur, it achieves high image quality throughout the entire focusing range, thus achieving sharp and high contrast image rendering.

It is not possible to compensate for distortion that is often observed with wide-angle lenses just by changing the aperture value. Therefore, the lens development stage was vital in ensuring minimized distortion. The SIGMA 24mm F1.4 DG HSM | Art adjusted the incidence angle of the light source from the surface of the first lens and positioned each aspherical glass element to optimize the power layout at respective positions. This has helped it succeed in minimizing distortion throughout the entire image.

For a lens with a large diameter, brightness in the peripheral areas tends to be consequently lower compared to the center. By improving the efficiency at large apertures and minimizing vignetting, it secures very good brightness. Without considering the lack of light even at the open aperture, it ensures high contrast images for indoor photography, astronomical photography and when photographing blue sky.

Flare and ghosting were thoroughly measured and monitored from the lens development stage to establish an optical design which is resistant to strong incidental light such as backlight. The Super Multi-Layer Coating reduces flare and ghosting and provides sharp and high contrast images even in backlit conditions.

With the optional SIGMA USB DOCK, you can update your lens firmware, adjust focus points and customize the setting of Full-time MF function and the timing to operate the Full-time MF function. By attaching this lens to a SIGMA USB DOCK, which is connected to a computer, the dedicated software “SIGMA Optimization Pro” offers various types of customization and adjustment.

With the new product lines, supplied hoods incorporate rubber for the connected part. Lens caps and AF/MF switches are also newly designed in order to improve usability. For the parts inside, metals and a new material called TSC (Thermally Stable Composite)*, which works well with metals, are located to achieve products with high accuracy. The lens barrel includes the year of release, engraved for users to recognize when the lens was released.

* TSC (Thermally Stable Composite) offers thermal expansion characteristics similar to those of aluminum. Parts made with TSC deform less, making possible lens construction of extremely high precision. 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.)

We used to measure lens performance with MTF measuring system using conventional sensors. However, we’ve now developed our own proprietary MTF (modulation transfer function) 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. The SIGMA 50mm F1.4 DG HSM will all be checked using this “A1” before they are shipped.

* A1: Aizu1

All SIGMA’s manufacturing – right down to molds and parts – with a few exceptions, are carried out under a single integrated production system, entirely in Japan. We are now one of the very few manufacturers whose products are solely “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.

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

The HSM (Hyper Sonic Motor) ensures a silent, high-speed AF function. By optimizing the AF algorithm, smoother AF is achieved. It incorporates a new full-time manual focusing mechanism that switches to manual focusing, simply by rotating the focus ring, even when AF is being used. This allows the photographer to make focus adjustments quickly and easily. With the optional SIGMA USB DOCK, you can also set it to conventional full-time manual focus override.

* Depending on the mount, initial operation of full-time manual focus differs

This lens incorporates a brass made bayonet mount which has both high accuracy and durability. A special treatment to reinforce its strength is applied to the surface giving it greater strength and making it highly resistant to long-term use.

As an experienced lens manufacturer that has been creating a diverse range of interchangeable lenses, we have started the innovative chargeable service “Mount Conversion Service”. With this service, the mount of your current SIGMA lenses can be changed to another mount of your choice. It gives a new life to your favorite lenses when you wish to use it on a different camera body.

* This “Mount Conversion Service” is different from a normal repair. In order to apply for the service, please see our Service & Support Section.