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RGB Zebra Oddity/Bug?

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RGB Zebra Oddity/Bug?
« on: 07 / May / 2008, 18:08:45 »
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I was learning how to use the RGB Zebra mode. I tested to see how it works by looking at a Granger Calibration Chart on my monitor then adjusting manual exposure to overexpose the various colors. The odd thing is that the red, blue, and green channels show when they are being overexposed and black shows where they are all overexposed but there's a huge white non-colored gap between the red green and blue channels and where they are all overexposed. Here's the odd part. If I put the Zebra Overexposure Threshold at 32 instead of my usual value of 1 then that blank white area gets filled in with the cyan, magenta, and yellow colors showing all the two-color channels being overexposed. Isn't that how its supposed to work all the time? Is there a bug in the software that subtracts or adds in that value of 32 that prevents the two-color channels showing overexposure? Am I just not using it right?

I'll attach a small example of a Granger Chart to show you what I was using. You can find them online or make them in your favorite editor by using the directions on this page How to Create Color Test Charts . Set your camera to overexpose in RGB Zebra mode while viewing one of these charts on your monitor and you'll see the big white or blank gap where the two-color channels are supposed to be showing overexposure. Then set your overexposure threshold to 32 and you'll see how it then works like it should, filling in the gap with the cyan, magenta, and yellow colors up to the blacked-out overexposure area.


 

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