![]() ![]() Thanks to our knowledge of lens design accumulated over a long period of time plus the latest lens manufacturing techniques, SIGMA has finally made the dream of a zoom lens with F1.8 throughout its entire focal range come true. zoom lens for digital SLR cameras with image sensors up to APS-C format. Images were shot in RAW on the EOS 700D, and converted in ACR using identical settings. It has enabled us to develop a wide glass-molded aspheric lens, and the incorporation of SLD (Special Low Dispersion) glass has optimized power distribution of the optical elements and compensated for various aberrations as well as curvature of field at the widest angle. The new SIGMA 18-35mm F1.8 DC HSM is the first zoom lens ever to offer an initial. The images were shot under controlled fluorescent lighting, and a custom white balance set from the Passport's own grey card using the Canon lens. Available for Mounts: Sigma, Sony, Nikon, Pentax, Canon Focal length: 18-35mm Maximum aperture: f/1.8 Minimum aperture: f/16 Lens construction: 17 elements in 12 groups Angle of view: 76. The 18-35mm f/1.8 is a member of the Art line and there’s a shiny little A on the lens barrel to indicate that. ![]() In addition, the technological innovation at our Aizu factory also contributes to better lens production. The Sigma 18-35mm f/1.8 DC HSM Art lens is part of Sigma’s new Global Vision program, which includes three lens lines: Art, Sports and Contemporary. SIGMA proudly introduces the 18-35mm F1.8 DC HSM next-generation. In order to compensate for astigmatic aberration across the entire focal range, we have relied on the experience and know how gained when designing our super wide angle zoom lenses such as SIGMA12-24mm F4.5-5.6 II DG HSM and SIGMA 8-16mm F4.5-5.6 DC HSM. Image quality until now found only in a fixed focal length lens. As the aperture value gets larger, the depth of focus becomes shallower, thus it makes the lens design extremely complicated in order to compensate for various distortions, such as spherical, axial chromatic and astigmatic aberration along with curvature of field. Razor sharp in center from F2.8 and outstanding from corner to corner at F4. Excellent sharpness in center from wide open between 18-28mm. I have read a lot of reviews and they seem to agree. Narrowing the aperture (selecting a higher-numbered aperture setting), results in more depth of field. ![]() The 35mm examples, with their narrower angle of view, have a more-diffusely-blurred background than the 18mm examples. To achieve a wide zoom lens with a maximum aperture of f1.8, various technical problems need to be overcome. The sigma 18-35/1.8 is known for being exceptionally sharp. 35mm: f/1.8 f/2.0 f/2.8 f/4.0 f/5.6 f/8.0 f/11.0 f/16.0. ![]()
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