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Post by echard on Sept 2, 2008 21:23:12 GMT -4
A friend of mine just produced a reply to the Mythbusters' A17 video showing the supposed "wires". www.youtube.com/watch?v=L9mYWWHREagAs predicted, no scratches on the cleaner copy. Whew, that was a close one...
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Post by ka9q on Sept 2, 2008 22:36:35 GMT -4
Another advantage to such a system, was that it didn't require the three colour tubes that an ordinary colour video camera of the time would have required, a reduction of weight by about 2/3rds I would imagine, not mention the power savings as well. This was in fact the major reason for choosing this sequential-color scheme. A very similar scheme had been proposed by CBS for broadcast use in the 1950s but lost out to the NBC "compatible color" scheme now known as NTSC and finally due to be phased out of over-the-air US television next year. Arguably the sequential color system was less efficient with bandwidth than NTSC. In the sequential scheme full and equal bandwidth was given to each of the red, green and blue images. This slowed down the effective color frame rate by a factor of 3 and produced that famous NASA video artifact of moving objects breaking up into colored images. The primary colors are not sampled at the same time. NTSC saves bandwidth by exploiting the limitations of the human eye. It remixes the RGB color signals into a luminance (B&W) signal plus two color components, I and Q. (The amplitude of I and Q is called "chroma"; their phase angle is called "hue"). The luminance signal is given the most bandwidth because the human eye has many more rods than cones. Less bandwidth is allotted to the I channel, and less still to the Q channel. The I color axis was chosen to correspond to human skin tone so that the system might reproduce it more accurately than other colors. These color signals were then multiplexed on a subcarrier overlaid on the luminance signal, and the frame rate isn't reduced.
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Post by JayUtah on Sept 2, 2008 23:30:34 GMT -4
As predicted, no scratches on the cleaner copy.
Golly, I've got that DVD set...somewhere.
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Post by Czero 101 on Sept 3, 2008 0:13:03 GMT -4
A friend of mine just produced a reply to the Mythbusters' A17 video showing the supposed "wires". www.youtube.com/watch?v=L9mYWWHREagAs predicted, no scratches on the cleaner copy. Whew, that was a close one... Great video! As predicted, no scratches on the cleaner copy.Golly, I've got that DVD set...somewhere. Same here... and a few other sets that no doubt have the same footage. Cz
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Post by ka9q on Sept 3, 2008 0:16:28 GMT -4
The kinescopes were made in the early 1970's mainly because the National Archives did not accept a non-film based medium to be archived. Thus all complete Apollo downlinks held at the Archives are kinescope, whereas those held by CBS would be their own 2" videotape. How good was kinescope technology in the early 1970s? I have seen kinescopes made of TV programs in the early 1960s before video recorders became widely used. They generally look awful. (I'm not sure, but I think I've seen some Honeymooners episodes recorded this way.) They'd look very contrasty and you'd get big black halos around light sources. But I don't know how much of that was the video camera, the CRT or the film. Movie film technology was already quite good by the 1960s so I would tend to discount it as a cause of significant kinescope artifacts, especially if it were run at the 30 Hz video frame rate instead of the usual 24 fps. Anybody know?
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Post by dwight on Sept 3, 2008 12:00:51 GMT -4
The NASA material was transferred to 16mm hi-res film. Kinescopes are particularly robust and cirumvented the need for standards conversion. However there is an increase in contrast and the resolution is not as good as the video source. The black halo around the lights on TV programs is actually due to the older pickup tubes.
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Post by bazbear on Sept 5, 2008 22:32:34 GMT -4
How 'bout a hydrogen-filled set? Great idea! Of course, adding a PA system announcement of "smoke 'em if you got 'em" would really be a blast
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Post by Data Cable on Sept 6, 2008 2:24:42 GMT -4
"smoke 'em if you got 'em" would really be a blast Not if there's no oxygen.
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Post by smlbstcbr on Sept 6, 2008 13:14:24 GMT -4
True, but ingenious nonetheless. A plus to that is that you have very high (relatively speaking) quality frames (though filtered by the cam filter). With NTSC, quality is sacrificed for the sake of color and speed.
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Post by fiveonit on Sept 17, 2008 23:48:05 GMT -4
Yes... I think that's what NASA did!A small excerpt from the film and stage crew on the Fake Apollo moon set. I got this from a Ex NASA employee who SWEARS the moon landings were faked!Director: "Alright guys... shine up those wires holding up the Astronauts so they're nice and shiny" Stage Hand: "Should we wipe them down with WD-40 so they're clean, shiny and oily?"Director: "Yep... that should do it! I just hope 40 years from now that some 14 year old kid, with a C- average, watching this video in his mom's bedroom doesn't see the wires. Then we're doomed!!"Stage Hand: "Should we tie a wire to each individual grain of fake moon soil?? We do have to simulate 1/6 gravity ya know" Director: "That'll take forever!!! And we've wasted enough time with that Earth Transparency in the CM window!! Let's just project everything at half speed to make it look right - That'll work!!"Stage Hand: "Then what's the point of the wires??"Director: "Hmmmmmm.... Good question"
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Post by Count Zero on Sept 18, 2008 1:04:13 GMT -4
You owe me a new keyboard, Fiveonit.
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Post by echnaton on Sept 18, 2008 9:21:17 GMT -4
Now everyone at work is looking at me. Wondering why I am wiping my monitor.
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Post by fiveonit on Oct 1, 2008 0:42:54 GMT -4
You owe me a new keyboard, Fiveonit. Can't prove it!!! Now everyone at work is looking at me. Wondering why I am wiping my monitor. Milk or Soda? I guess I'm glad I made someone's day!
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Post by dragonblaster on Oct 20, 2008 6:43:34 GMT -4
It's not easy being an atheist. Really puts a crimp on the old valedictions, curses and oaths.
My favorite MB boom was the myth about the WWII bomb and the French railway station. Why on earth the real LOL moments in MB for me tend to be huge explosions I have no idea.
If it were my house, I very, very much doubt I would be ROFPMSL!
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Jason
Pluto
May all your hits be crits
Posts: 5,579
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Post by Jason on Oct 20, 2008 12:16:16 GMT -4
The water heater rocketing up out of the little red shack was pretty good too, IMO.
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