‘Every hair on his head is numbered.’
It is estimated that a well-exposed fine-grained 35 mm negative of a focus chart can resolve to the equivalent of about 3000 pixels across the frame. To sample an image adequately, the scanning resolution must be somewhat finer than the detail in the image, so as to avoid sampling artefacts (such as the Moiré patterns formed by striped shirts seen on TV). Because of camera movement, image movement, depth of field limitations and printer slippage, images on film rarely approach the negative's own resolving power.
According to the system used, data in digital film systems may have between 2048 and 4096 pixels per line, and a proportional number of lines (for a full ...