A technique for selective lightening of an area of a print by giving it additional exposure. This is accomplished usually by blocking the projected image during exposure using the printer's hands, creating a small opening with them to let the light fall only on the selected image area. Because the hands cast a soft-edged shadow, this limits the ability to burn in small areas accurately. Sometimes this can be worked around by cutting an appropriately shaped hole in a piece of thin cardboard to wave over the picture. See Dodging. Contrast The range of tonality of an image. A high contrast picture is one with detail in dark shadows as well as bright highlights. A low contrast picture is lacking in either bright highlights or dark shadows, or both, with only the midrange represented. Photographic film can hold a higher range of contrasts than can printing paper. A high contrast slide will usually print with some loss of shadow and highlight detail unless extra steps are taken, such as dodging and burning, the use of a contrast mask, or by utilizing printing paper with different contrast ranges.
A process used in custom print making wherein after the initial exposure on the enlarger, A second exposure is made, with portions of the image shielded from the light in order to give the unshielded portions of the image additional exposure. Typically used on the areas of an image occupied by sky in order to bring out details of clouds.