when only a couple sheets are processed in a tube that has the capacity to hold more sheets because the a minimum amount of chemistry is required for the tube to work properly. Processing can be accomplished with the lights on with almost all rotary tube processing systems because they have light-tight covers. The photographer can also generally keep his/her hands free of chemistry, since the solutions are enclosed in the tubes. Also, since many rotary systems have or use a water bath, the bath can be temperature-controlled, resulting in very consistent results across different processing runs. Drawbacks with a one-film-per-tube method is that processing any amount of film can take a very long time; it's difficult to keep up with more than one or two tubes at a time. Also, a mechanized rotary system, depending on its features and capabilities, can be very expensive. Benefits Sheet film is, simply enough, big, and as such has a proportionately great ability to hold information. The image on a piece of sheet film has approximately fifty-six times the surface area of a standard 35mm image. As compared to megapixels, when taking the LP/mm resolution of 8x10 Velvia the resolution is up to a value of 5,285 megapixels. In theory, the "enlargability" of such an image is proportionately great although the very high image quality of small format lenses sometimes allows somewhat greater magnifications than some large format lenses. However, this is not always the case. Sheet film can be enlarged to poster, or even billboard, size with acceptable quality. It is far easier to do retouching directly on the surface of a sheet of film since the images are large, than on smaller formats. Many of the larger formats can be contact printed, and for some ultra-large formats, are only contact printed. Each sheet can receive individualized processing. Since each exposure is its own sheet, it's possible to alter development, based on the contrast of the photographed scene, to best fit the dynamic range of the subject. Because of this, many large-format photographers are also practitioners of the Zone System. Because of the large size and very manual single-use nature of sheet films, it's possible to use a single sheet for more than one exposure. Using a dark slide which has been cut in half, turning a standard format into a long, skinny panoramic format is simple and very cost effective. While