Pentax Optio Optio WG-1 Operating Manual page 36

When the image is underexposed, the part to the left is cut off (dark
portions) and when the image is overexposed, the part to the right is cut
off (bright portions).
This camera has a function where overexposed areas are indicated as
blinking red and underexposed areas as blinking yellow.
Understanding Contrast
The graph peaks gradually for images in which contrast is balanced. The
graph peaks on both sides but sinks in the middle for images with a large
difference in contrast and low amounts of mid-level brightness.
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