Editing Micrograph (section)

==Magnification and micron bars==
Micrographs usually have micron bars, or magnification ratios, or both.

[[Magnification]] is a ratio between the size of an object on a picture and its real size. Magnification can be a misleading parameter as it depends on the final size of a printed picture and therefore varies with picture size. A ''scale bar'', or ''micron bar'', is a line of known length displayed on a picture. The bar can be used for measurements on a picture. When the picture is resized the bar is also resized making it possible to recalculate the magnification. Ideally, all pictures destined for publication/presentation should be supplied with a scale bar; the magnification ratio is optional. All but one (limestone) of the micrographs presented on this page do not have a micron bar; supplied magnification ratios are likely incorrect, as they were not calculated for pictures at the present size.