Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Early Color Television (http://www.videokarma.org/forumdisplay.php?f=36)
-   -   early Network color was not equal (http://www.videokarma.org/showthread.php?t=141244)

old_tv_nut 01-01-2008 02:33 PM

1 Attachment(s)
100% amplitude bars are NOT good for playing through a RF modulator. The NTSC system (and PAL) are designed to overmodulate the yellow and cyan bars in this case, since such full amplitude colors are almost never encountered in natural scenes.

The 75% bars are not 75% saturated, they are 100% saturated, but 75% amplitude. However, they are usually set next to a 100% white bar, which makes all of them look darker by comparison. When this pattern is used, it happens that the yellow bar chroma peaks equal the amplitude of the 100% white bar, so it is safe from overmodulation.

The picture posted by Pete is actually quite good, just the white balance and exposure of the still camera is off. I have attached an adjusted copy, which should be much closer to the visual effect in person.

yagosaga 01-01-2008 03:23 PM

Quote:

Originally Posted by old_tv_nut (Post 1551326)
The 75% bars are not 75% saturated, they are 100% saturated, but 75% amplitude. However, they are usually set next to a 100% white bar, which makes all of them look darker by comparison. When this pattern is used, it happens that the yellow bar chroma peaks equal the amplitude of the 100% white bar, so it is safe from overmodulation.

Thank you very much for this correction!

Quote:

The picture posted by Pete is actually quite good, just the white balance and exposure of the still camera is off. I have attached an adjusted copy, which should be much closer to the visual effect in person.
This picture with adjusted white balance does reveal what the the visual effect in person on a CT100 might be.

Here is a link to color bars on a 15GP22 which looks similar to your adjusted copy:

http://bs.cyty.com/menschen/e-etzold...5inBetrieb.jpg

- Eckhard

old_tv_nut 01-01-2008 03:54 PM

That link is very interesting - was the original a film or print rather than digital? (The color rendition just strikes me that way)

Pete Deksnis 01-01-2008 04:12 PM

I just got back from a trip to two food stores and am playing catchup. Looks as though everybody's ok with everything. Maybe i shoulda left earlier:D You're right about the adjusted copy matching the screen; maybe just a little less red, but it's amazing how similar the original (posted earlier) and adjusted look through the filters.

yagosaga 01-01-2008 04:30 PM

Quote:

Originally Posted by old_tv_nut (Post 1551452)
That link is very interesting - was the original a film or print rather than digital? (The color rendition just strikes me that way)

This photo is digital. The room was illuminated by a bulb. Hence the yellowish background.

- Eckhard


All times are GMT -5. The time now is 12:32 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.