misleading.

I use a single histogram as a simplified example. DON'T use a histogram to set exposure unless you have a color (RGB) histogram!

SETTING EXPOSURE

Warning: I show a single histogram to simplify. DON'T use a single histogram to set exposure! You need a color histogram, otherwise you may overexpose colored areas and not know it. Read on to Color Histograms (page 83) after you read this.

Contrary to your camera manual, the histogram doesn't have to be in the middle. Black cats in coal mines may only use the left half. Snow scenes may only use the right half.

The critical thing for which a histogram is helpful is to determine if any highlights have been clipped and washed out. Overexposure is death for a digital image. Histograms make this easy to check. If you have washed-out areas of 100% white (digital value 255) you'll see a tall vertical line at the far right of the histogram.

If you blow an image to smithereens you'll see more than just one line peaked on the right. You may see a train wreck!

© 2007 KenRockwell.com

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converted by Sándor Nagy