It is a fully manual lens with no electronics. The photographer must expose manually and focus manually. If you are not comfortable with manual exposure or manual focus this lens will not be suitable for you.
As Samyang 85mm photo lens does, this VDSLR lens also has an outstanding optical function. Hybrid aspherical lens (H-ASP) has a specially designed curved surface to minimize color aberration and realize exceptional image quality and high contrast throughout center to corner of image even when aperture is fully opened.
Samyang’s 50mm F1.4 AS UMC is a fast-aperture, manual focus photo lens designed for full frame image sensors as well as APS-C and smaller sensors. The low F number allows precise control of depth of field as well as the ability to shoot in relatively dark environments.
EOS 6D, EOS 7D, EOS 20D, EOS 20Da, EOS 30D, EOS 40D, EOS 50D, EOS 60D, EOS 60Da, EOS 70D. EOS 300D/Digital Rebel, EOS 350D/Digital Rebel XT, EOS 400D/Digital Rebel XTi, EOS 450D/Rebel XSi, EOS 500D/Rebel T1i, EOS 550D/Rebel T2i, EOS 600D/Rebel T3i, EOS 650D/Rebel T4i, EOS 700D, EOS 1000D/Rebel XS.