Pentax K20D manual Changing Playback Display Method, Using the Histogram, Histogram Display p.26

Playback Functions

182Changing Playback Display Method

The camera switches display information when you press the M button in the Playback screen.

Standard	Captured image and indicators are displayed.
Histogram	Images and histogram (Brightness/RGB) are displayed.
Detailed Info	Shooting information appears with a small image in the
	upper left.
No info. Display	Only captured images are displayed.

• Refer to p.25 for various display information details.

•The information that is shown first during Playback is the last screen that was displayed in the previous session. The information can also be displayed from Standard when setting in [Memory] (p.236) in the [A Rec. Mode] menu.

Using the Histogram

A histogram shows the brightness distribution of an image. The horizontal

7 axis represents brightness (dark at the left and bright at the right) and the vertical axis represents the number of pixels.

The u features two histogram displays. The “Brightness histogram” shows the distribution of brightness and the “RGB histogram” shows the distribution of color intensity.

1 Histogram Display (p.26)

pixels→
Number of
	(Dark) ←Brightness→ (Bright)
Dark	portions	Bright portions

The shape of the histogram before and after shooting tells 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.

1 Adjusting the Exposure (p.100)