Incredible rendering performance delivers unprecedented visual experiences. Enjoy enhanced control of light and composition.
SIGMA has extensive experience in leveraging its advanced design capabilities and leading-edge technologies to craft large-aperture prime lenses that bring out the full potential of ultra-high-megapixel DSLRs. As its latest achievement in this category, SIGMA has created an ultra-wide-angle lens with F1.4 brightness. With a focal length of 20mm and F1.4 aperture, this lens delivers outstanding large-aperture brightness and bokeh, delivering unprecedented visual experiences. Allowing the photographer to leverage the perspective provided by the wide-angle and the shallow depth of field provided by the large aperture, this lens is ideal not only for such ultra-wide-angle subjects as landscapes and starry skies, but also for snapshots in low light, indoor photography, portraits with a natural bokeh effect, and much more.
World’s first 20mm F1.4 lens — thanks to advanced large-diameter aspherical lens manufacturing technologies
To offer an ultra-wide-angle 20mm focal length and F1.4 brightness at wide-open aperture, this lens incorporates a large double aspherical lens 59mm in diameter. Lenses of this type had been considered extremely difficult to manufacture, but SIGMA took on the challenge to realise an F1.4 ultra-wide-angle lens that fulfils the strict performance requirements of the SIGMA Art line. What made this breakthrough possible were SIGMA’s advanced manufacturing technologies, which the company has developed over time by producing a wide range of ultra-wide-angle and large-aperture lenses. For example, milestone lenses such as SIGMA 12-24mm F4.5-5.6 EX DG ASPHERICAL HSM, SIGMA 8-16mm F4.5-5.6 DC HSM, and SIGMA 18-35mm F1.8 DC HSM | Art were completely original products that helped SIGMA develop outstanding design and production know-how and its current high-precision, high-efficiency production system. In turn, these advances made possible the new SIGMA 20mm F1.4 DG HSM | Art. Moreover, SIGMA’s advanced optical design minimizes distortion, transverse chromatic aberration, sagittal coma flare, and the reduction of brightness toward the edges of the image. Delivering top performance even at wide-open aperture, this lens can be considered the culmination of SIGMA’s Art line.
Minimised Chromatic Aberrations
This lens minimises chromatic aberrations, a common issue in large-aperture ultra-wide-angle lenses. It features two FLD (“F” Low Dispersion)* glass and five SLD (Special Low Dispersion) glass elements to minimise transverse chromatic aberration, which is mainly visible around the edge of the image. The optimised lens power distribution helps minimise axial chromatic aberration. As a result, this lens delivers high image quality in every situation without colour smearing, and its rendering performance is consistently sharp with high contrast.
FLD glass is ultra-low-dispersion glass that offers performance of the highest level. Highly transparent, its refractive index and dispersion are extremely low as compared to conventional types of glass. It offers characteristics very similar to those of fluorite, which is valued for its high anomalous dispersion. These characteristics minimise residual chromatic aberration (secondary spectrum), which cannot be corrected by ordinary optical glass, while helping to produce sharp, high-contrast images.
Distortion is a common issue in wide-angle lenses, and it is not possible to correct it simply by changing the aperture value. For this reason, a lens must be designed from the start to minimise this issue. By adjusting the incidence angle of light starting with the first lens element and incorporating optimally positioned aspherical glass elements, the SIGMA 20mm F1.4 DG HSM | Art lens minimises distortion throughout the entire image.
Designed to Minimise Flare and Ghosting
From the start of the design process, SIGMA took steps to minimise flare and ghosting and establish an optical design that is resistant to strong incidental light sources such as backlight. At the prototyping stage, SIGMA used not only simulations but actual photographic experiments to assess flare and ghosting under multiple criteria, identify the causes of these issues under a wide range of situations, and take measures to mitigate them. In addition, SIGMA’s Super Multi-Layer Coating helps further reduce flare and ghosting and provide sharp, high-contrast images even in backlight conditions.