Before revision: distinguishes the following types: Mechanical vignetting Optical vignetting Natural vignetting A fourth cause is unique to digital imaging: Pixel vignetting A fifth cause is unique to analog imaging: Photographic film vignetting Mechanical vignetting Mechanical vignetting occurs when light beams emanating from object points located off-axis are partially blocked by external objects such as thick or stacked filters, secondary lenses, and improper lens hoods.
After revision: (laterally or vertically off from the optical axis of an optical system under consideration)of the optical systemdistinguishes the following types: Mechanical vignetting Optical vignetting Natural vignetting A fourth cause is unique to digital imaging: Pixel vignetting A fifth cause is unique to analog imaging: Photographic film vignetting Mechanical vignetting Mechanical vignetting occurs when light beams emanating from object points located off-axis are partially blocked by external objects such as thick or stacked filters, secondary lenses, and improper lens hoods.