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  Apollo 11: Black and white lunar TV camera

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Author Topic:   Apollo 11: Black and white lunar TV camera
BBlatcher
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Posts: 57
From: Savannah, GA, USA
Registered: Aug 2011

posted 09-03-2012 07:17 PM     Click Here to See the Profile for BBlatcher     Edit/Delete Message   Reply w/Quote
The video camera that recorded Armstrong's first step on the moon was black and white. Yet the crew had a color camera for use within the cabin. So why was camera that recording that historic a black and white camera?

FullThrottle
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Posts: 93
From: Seattle, WA, USA
Registered: Sep 2010

posted 09-03-2012 07:25 PM     Click Here to See the Profile for FullThrottle   Click Here to Email FullThrottle     Edit/Delete Message   Reply w/Quote
I'd have to say its because the color 16mm camera was not being broadcast live, and the tapes only viewed after recovery, post mission...

The B&W camera was purposely built for live broadcast to the world. A standard live color camera in 1969 was hundreds of pounds and very massive in size. It was a technological feat to shrink it down to less than 10lbs and make it handheld.

Robert Pearlman
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Posts: 43576
From: Houston, TX
Registered: Nov 1999

posted 09-03-2012 07:26 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
From TVTechnology:
Dick Nafzger, a NASA employee involved in video for more than four decades, explained the decision to restrict the feed from the lunar surface to black and white.

"We had narrowed the bandwidth as much a possible to try and get a good S/N, "Getting TV from the moon was a big unknown. We figured that slow scan video would give us the best chance for locking onto [the signal] with a 210-foot dish."

Nafzger observed that at time, Apollo missions had a fairly wide bandwidth FM link to Earth for telemetry and voice communications — so wide in fact, that it was possible to send nearly full bandwidth 525/60 NTSC video back from both the command module and the lunar lander. However, a design decision was made to limit the LEM video transmissions to 500 kHz to assure a good signal-to-noise ratio from the moon's surface, as there were many unknowns, including a small transmitting antenna and low power transmitter. This necessitated a reduced resolution/slow scan television system.

"It was obvious that we couldn't do color," he said. The first [lunar landing] mission wasn't going to change to include a color camera. It was only after this that we began to get confident that we could handle three MHz from the moon's surface."

Dwight
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Posts: 577
From: Germany
Registered: Dec 2003

posted 09-06-2012 01:44 PM     Click Here to See the Profile for Dwight   Click Here to Email Dwight     Edit/Delete Message   Reply w/Quote
The path chosen to use a black and white slow scan camera is detailed in the book, "Live TV From the Moon".

The LM was capable of sending color pictures, but due to the technology not being tested for use on the lunar surface, proposals for a sequential color system were quickly dismissed. As Dick Nafzger points out, it was still a big unknown and so the opted to go SSTV.

There was a little-known proposal however to send color pictures as a backup by using a mechanical color wheel system which could be attached to the TV camera's existing lens. This idea was also nixed as it was too close to launch to test it properly. Despite the sequential color system being ready, its use on Apollo 12 was not guaranteed, and it was put through a number of tests prior to that mission. Indeed the whole idea of color TV being used so soon on the Apollo missions is thanks largely to Tom Stafford, who argued for the development for use on his Apollo 10 flight. Original plans would have implemented the color system around 1971.

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