It has very little distortion, chromatic aberration, or vignetting. Distortion, vignetting, and chromatic aberration are all well controlled. Vignetting is often an unintended and undesired effect caused by camera settings or lens limitations. The f/3.5 lenses all show vignetting at smaller apertures whereas the f/2.8 lenses do not. This lens has shown to have lower vignetting than other Canon 50mm lenses. DX lenses may produce vignetting when used on film and FX cameras. The 6-bit code on lenses gives information about optic vignetting characteristics, permitting software adjustment. This type of vignetting is caused by the physical dimensions of a multiple element lens. However, this results in additional field curvature and vignetting. All DA lenses can be mounted on Pentax film bodies, albeit with increased vignetting. Pixel vignetting only affects digital cameras and is caused by angle-dependence of the digital sensors. The Nikon 1 series and the Pentax Q series can use C-mount lenses without vignetting. This marginal coverage field produces images with often pronounced vignetting. Although vignetting is still an issue, photos can be taken, and infinity focus achieved. There is a fair amount of vignetting, wide open.