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The first practical X-ray television system in the UK was developed by Dr George Hay at Leeds General Infirmary. The image was formed on a high speed fluorescent screen, and the light produced focused onto the target of an Image Orthicon. In order to utilize as much of the available light as possible a mirror optical system was used. The Mirror optical system was produced by Odelca, and the television camera was a modified broadcast camera, made by Marconi.
The whole assembly was huge, the camera tube alone is about 1m long!   

Although the image quality was poor by today's standards, it was much better than could be achieved using the naked eye to view a fluorescent screen. The light out of a fluorescent screen under normal clinical conditions is about the same as you would get from a sheet of white paper viewed by starlight. That is, a night with no moon and no cloud. Under these conditions, the contrast and spatial resolution is set by the eye of the observer.
Modern X-ray televisions systems have used an image intensifier to boost the amount of light from a fluorescent screen, the light being amplified more than 10,000 times, before being focused on the target of small, high resolution camera tube. This arrangement is now being replaced by solid state digital panels, much the same as the chip used in a digital camera, but about 45 x 45 cm in size, having 2,000 x 2,000 pixels, and a bit depth of up to 16 bits.