Magnification and Micron Bars
Micrographs usually have micron bars, or magnifications, or both.
Magnification is a ratio between size of object on a picture and its real size. Unfortunately, magnification is somewhat a misleading parameter. It depends on a final size of a printed picture, and therefore varies with variation in picture size. Editors of Journals and Magazines routinely resize a figure to fit the page, making any magnification number provided in the figure legend incorrect. Scale Bar (or Micron Bar) is a bar of known length displayed on a picture. The bar can be used for measurements on a picture. When a picture is resized a bar is resized with also. If a picture has a bar, the right magnification can be easily calculated. Ideally, all pictures intending for publication/presentation should be supplied with a scale bar; magnification is optional. All but one (of a limestone) micrographs, presented on this page do not have a micron bar; supplied magnifications are the wrong ones (they were not calculated for pictures of present size).
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