No lens is optically perfect. In the ideal world, every lens would produce a sharp, undistorted, evenly illuminated image that’s sharp from edge to edge. Some lenses come close, but the fact is that lens designers have to work within the limitations of the laws of physics and the glass materials they have available, and […]
An optical effect in some lenses where straight lines come out slightly bowed. You often see ‘barrel distortion’ with wideangle lenses or ‘pincushion distortion’ with telephoto lenses at their longest zoom setting. More expensive lenses tend to have less distortion but, generally, the longer the lens’s zoom range the more likely you are to see distortion creeping in.