Here is the netbox 7600 brochure as iPlayer/netbox friendly HTML.
With this image, one half simulates scaling of the other half. At a distance from the screen when both sides look the same, you are at a viewing distance of twice the optimum - if at 4 metres from the screen both halves look the same, then your optimum viewing distance is 2 metres.
Copyright (c) 2006 Robert Forsyth