field sequential color video

[DaveWM]

I tried seaching, Just want to know if there is a video of one of these systems operating?

[Sandy G]

I THINK Apollo 12 used one...The SECOND moon landing. Remember 11 was in B&W, for some reason or another they couldn't get/didn't think a color camera would work on the moon, or maybe because a small, light color camera had yet to be developed..

[DaveWM]

I was just hoping for a you tube video or such showing how they look. I see photos of the receivers over on the ETF site, but could not find one with a video.

[Steve McVoy]

The only way to show field sequential color in a video would be to photograph the screen. Assuming you could deal with the frame rate differences, it wouldn't look any different from a video of NTSC. Still photos show the color quality and resolution well.

It would be possible to show the "color fringing" problem by taping something like a basketball game.

When the History Channel program "Failed Inventions" from the Modern Marvels series airs again, you can see a small amount of field sequential color in it.

[David Roper]

I suppose recording the CBS System on a camera using the NTSC scan rates would end up a strobing, artifact filled mess. That's probably why there hasn't been any posted. You can, however, get true-to-life video of a Col-R-Tel type of converter. There's one playing in the background of the video presentation of the 2003 Early TV Convention in all its flickering glory. In fact, if you pause the VHS and advance frame by frame you can see the converter step through its sequential fields: red, green, blue, red, green, blue....

[Phil Nelson]

I took this snapshot of a b/w set using a CBS color converter at the last ETF convention.



As Steve noted, a still photo basically shows you what there is to see. An average person walking by will say, "Hmm, that's a nice looking color TV."

To me, the only difference from a conventional picture was some flickering. Perhaps that's more evident to some people than others, like the strobing from fluorescent lights.

This converter uses a magnifying lens, so some of the reflections & whatnot in the snapshot result from that.

As with all TV shots, the only way to get a true depiction of the screen image is to turn down the room lights somewhat. My memory is that this screen looked deeper and less washed-out than it appears in this snapshot.

Phil Nelson

[DaveWM]

well next up is I want to build one

I will have to add that to me "to do list"

[Phil Nelson]

You may remember this thread with a DIY article from Popular Science.

http://videokarma.org/showthread.php?t=247597

Phil

[wa2ise]

Originally Posted by Sandy G

I THINK Apollo 12 used one...The SECOND moon landing. Remember 11 was in B&W, for some reason or another they couldn't get/didn't think a color camera would work on the moon, or maybe because a small, light color camera had yet to be developed..

Also very limited bandwidth from the RF path from the Moon to Earth. NASA threw it together just a few months before the moon landing. Slow scan TV. And at the receiving site in Australia, they used a pair of crude scan converters to make it 525i/30frames (NTSC B&W)) and 625i/25frames (PAL B&W) to feed the TV stations around the world. This scan converters were essentially a CRT display with long persistence prosper running at the slow scan rate, and regular B&W cameras operating at NTSC and PAL rates looking at that display. Heard it said that the slow scan video was significantly better than what the world saw live off those scan converters, but NASA can't find the tapes (they suspect someone in need of tape erased and reused them). A few still camera photos exist though.

Think NASA used sequential color on some early shuttle missions. Saw some footage of a shuttle crew launching a satellite, and as the satellite rotated, you could see color artifacts.

The astronauts on Apollo 12 accidentally pointed the camera at the Sun while moving it, and burned out the camera tube sensor. It didn't hurt the mission except for a huge loss of public interest (what, no more moon landing video?). That and "Been there, done that" didn't help.

[Steve McVoy]

Here is a .wmv file from Cliff Benham:

http://www.earlytelevision.org/2010_...n_photos3.html

[ceebee23]

I still find field sequential / spinning disks amazing. We all understand the principle but somehow it remains fascinating that it works so well!

Must get round to sorting out a color wheel set!

[DaveWM]

SOOO COOL

I have got to get one of those...