Sigma Art 24mm F1.4 DG HSM

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.

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