F4 Simulator
As OLDSIMMAN has said the F4 simulators had 2 models. A high level transit model and a 2nd model known as the 3 Facet model. This was a triangular shaped frame which was designed to carry 3 separate models . In the F4s only two facets were used one carried airfield model and the other the Ground attack model. When a model change was demanded the whole model frame was retracted away from the horizon mirrors, rotated to bring the new model into position and then raised back into the mirrors. The whole sequence took about 2 minutes during which time the picture was in simulated cloud.
The big problem was that the whole visual system was very maintenance intensive. The cameras used were standard Phillips / Pye studio cameras. The ones on the F4s were LDK33s which were designed for use as tele-cine or fixed caption work. The cameras were capable of producing superb images in a studio environment. The problem was that in the simulator the depth of field was required to be from a few inches to approx. 30 feet, consequently the lens aperture to achieve this was extremely small. This meant that the camera video gains were always up towards maximum and the tubes (plumbicons) degraded quite quickly. Similarly with the projectors, to get an adequate daylight brightness level on the screen the system was always working flat out and the tube phosphors quickly lost brightness. The picture displayed to the pilot was always good immediately following a tube/plumbicon change but a month later was normally very poor.
On the Phantom another short coming was the scene displayed on approach. At 0 degrees pitch angle the horizon was at approximately the centre of the screen (Pilots Eye height). When the aircraft was on approach the horizon moved down the screen to reflect the pitch attitude, the trouble was the runway dropped off the screen, there was of course no peripheral vision, this was a bit of a bummer if you were trying to do a visual approach . The solution was to pitch the visual scene down on the approach. The aircraft instruments continued to show the correct attitude.