Here is some additional info:
- The concept of the first generation SIGMA 50mm F1.4 DG HSM | Art has been completely redesigned.
- By introducing all the latest technologies and maintaining the highest class of optical performance, we achieved both the optimal size and high-speed AF required for today’s mirrorless systems at a high level.
- In addition to the brightness and large, beautiful bokeh produced by the large aperture of F1.4, various aberrations are optimally balanced to pursue uniform and well-balanced image quality from the center to the periphery of the image.
- Based on the latest optical design technology, it is equipped with 14 lenses in 11 groups, including 3 aspherical lenses and 1 SLD glass.
- It effectively suppresses various aberrations such as astigmatism and curvature of field that cannot be corrected in the camera.
- Despite its large aperture of f/1.4, it is designed to pursue imaging performance in the image periphery, suppress sagittal coma flare, and withstand harsh starscapes and nightscapes with point light sources from wide open.
- Clear image quality with no color bleeding over the entire image circle.
- For the first time in the Art line, we have adopted the linear motor “HLA” (High-response Linear Actuator).
- By adopting a double-sided aspherical lens for the focus element, high-speed and quiet focusing and high tracking performance are achieved despite the large aperture.
- By adopting a double-sided aspherical lens for the focus element, high-speed and quiet focusing and high tracking performance are achieved despite the large aperture.
- The lens barrel is equipped with a focus mode switch, a switch that turns the aperture ring click ON/OFF, an aperture ring lock switch that prevents inadvertent operation, and an AFL button that can be assigned any function from the camera.
- It has a dust- and drip-proof structure, and the front element of the lens has a water- and oil-repellent coating.
via Digicameinfo