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Re: White Balance

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john lenihan
Re: White Balance
on Oct 3, 2017 at 4:37:36 pm

Color balance. That could be a long long discussion.

It sounds like the number it tells you in Kelvin when it does the auto white balance is not accurate, or rather, not using the same calibration as when you set it manually. If I were you I would try this experiment, then find out which color temperature gives you the same picture tone. Then mentally use that offset number when you set it.

This error can easily happen if you are shooting with LED lighting, or possible two different colors of light, like daylight plus fluorescent.

Color in degrees Kelvin assumes black body radiation. In other words, a graph of energy vs frequency (which we interpret as color) would look like a bell shaped curve. Remember the curve in school.

This is true for sunlight and incandescent lighting. Your eye interprets the highest point of the curve, the average, as the color temperature of the entire light, even though other colors are present.

If you have LED lighting, it does not produce a bell shaped curve of light. It produces two spikes of light, usually one yellow and one blue. The automatic white balance tries to look at two spikes of color and guess what the average is. The average is actually between the two spikes. There is no perfect way for it to average two peaks and give you one answer that represents a bell shaped curve. So, the designers had to put in some kind of firmware to guestimate this.

John Lenihan

LeniCam Video Productions

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  • White Balance by Gordon McLean on Oct 3, 2017 at 3:39:11 pm
    • Re: White Balance by john lenihan on Oct 3, 2017 at 4:37:36 pm

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