Pentax Optio W90 Black Optio W90 Black Optio W90 Manual - Page 36

Histogram Number of pixels→ A histogram shows the brightness distribution of an image. The horizontal axis represents brightness (dark at the left and bright at the right) and the vertical axis represents the number of pixels. (Dark) ←Brightness→ (Bright) The shape of the histogram before and after shooting tells Dark portions Bright portions you whether the brightness and contrast are correct or not, and lets you decide if you need to use EV compensation and take the picture again. Setting the Exposure (EV Compensation) 1p.133 Understanding Brightness If the brightness is correct, the graph peaks in the middle. If the image is too dark, the peak is on the left side, and if it is too bright, the peak is on the right side. Dark image Correct image Bright image When the image is too dark, the part to the left is cut off (dark portions) and when the image is too bright, the part to the right is cut off (bright portions). The Optio W90 has a function where bright portions are indicated as blinking red and dark portions 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. 34