compared with the
Samyang 14mm f/2.4 SP the Sigma 14mm f/1.8 is bigger, heavier, more expensive and with more much coma and astigmatism below f/4 but is weathersealed, better build quality, has less vignetting and less distortion so better for lowlight photojournalism, moonlit scenes at 2 sec exposures, timelapse imagery or video