a 7-degree field of view. The aperture ranged from F4 to F44, with a T5 light transmittance rating. Color decoding and signal processing Signal processing was needed at the Earth receiving ground stations to compensate for the Doppler effect, caused by the spacecraft moving away from or towards the Earth. The Doppler Effect would distort color, so a system that employed two videotape recorders (VTRs), with a tape-loop delay to compensate for the effect, was developed. The cleaned signal was then transmitted to Houston in NTSC-compatible black and white. Unlike the CBS system that required a special mechanical receiver on a TV set to decode the color, the signal was decoded in Houston's Mission Control Center. This video processing occurred in real time. The decoder separately recorded each red, blue and green field onto an analog magnetic disk recorder. Acting as a framebuffer, it then sent the coordinated color information to an encoder to produce a NTSC color video signal and then released to the broadcast pool feed. Once the color was decoded, scan conversion was not necessary, because the color camera ran at the same 60-fields-per-second video interlace rate as the NTSC standard. Operational history It was first used on the Apollo 10 mission. The camera used the command module's extra S-band channel and large S-band antenna to accommodate the camera's larger bandwidth. It was only used in the lunar module when it was docked to the command module. Unlike the earlier cameras, it contained a portable video monitor that could be either directly attached to the camera or float separately. Combined with the new zoom lens, it allowed the astronauts to have better precision with their framing. Apollo 12 was the first mission to use the color camera on the lunar surface. About 42 minutes into telecasting the first EVA, astronaut Alan Bean inadvertently pointed the camera at the Sun while preparing to mount it on the tripod. The Sun's extreme brightness burned out the video pickup tube, rendering the camera useless. When the camera was returned to Earth, it was shipped to Westinghouse, and they were able to get an image on the section of the tube that wasn't damaged. Procedures were re-written in order to prevent such damage in the future, including the addition of a lens cap to protect the tube when the camera was repositioned off the MESA. The color camera successfully covered the