When we talk about digital cameras, we relate to the terms ' full-frame or 'APS- C (cropped) detector '. The detector sizes of these cameras are analogous to the size of a 35 mm frame of film. As similar, the digital cameras that are generally used by numerous shutterbugs moment are categorized as the small format. Medium format photography entered the digital realm back in 1991, with the preface of a device that replaced the film holder on the reverse of an analog camera. Here an expert photographer says Yvette Heiser ,this device was aptly named a 'digital camera back' as it contained an electronic image detector, which allowed digital film-land to be taken rather than film.