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Chromakey CMYK values

Posted: Mon, 8th Feb 2010, 1:25pm

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xtremed

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Does anyone knows what values you need for chromakey green in CMYK values?

We want to replace our standard backdrop system with a presentation system like the picture below, but i don't know the exact values for green.

Posted: Mon, 8th Feb 2010, 1:35pm

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Joshua Davies

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You can't easily reproduce chroma green in CMYK - it normally comes out pretty dull when printed. You would be much better off using a pantone colour like Pantone 354. Hope this helps.
Posted: Mon, 8th Feb 2010, 1:41pm

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xtremed

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tnx for the quick reply, but wouldn't it be possible to open the pantone colour in photoshop and simply copy the cmyk values of that colour?
Posted: Mon, 8th Feb 2010, 1:50pm

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Joshua Davies

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Most Pantone colors cannot be simulated in CMYK (when it comes to the printing stage). I believe they use 15 pigments rather than just CMYK to produce the colours, hence they can be more solid and vivid...
Posted: Mon, 8th Feb 2010, 1:55pm

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xtremed

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Okay thanx! I'll ask the producer of the stands how they print it wink cmyk or pantone
Posted: Wed, 10th Feb 2010, 2:48pm

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njush

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Schwar is the expert of course, but just something to consider...
The precise numerical color printed onto your background is on one piece of the puzzle.

The color that ultimately matters is the RGB value of the screen in the photos that you import into PK. (PK indicates that it's using RGB difference keying rather than old-style chroma keying). The color in the photos are the result of 3 key factors ...
1) The color of the screen
2) The temperature of your lighting
3) The white balance setting of your camera

Your ultimate goal is to have a very high Green channel value, and very very low Red and Blue channel values.

Ideally, you would setup your background and lighting, and shoot a gray card to custom configure your camera's white balance to the lighting. Then, hang a series of green color chips from a Pantone book on your background and shoot photos using the calibrated white balance and lighting.

Select your color by importing the photos into photoshop or any other application that allows you to measure the RGB values of the image pixels. The green chip that provides the highest green channel value with lowest values in blue and red channels (Ideally something close to or over 200 in green and 50 or below for red and blue for an 8 bit image) is going to be the ideal color for your configuration.