|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
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.