How to Read a Histogram

The LCD lies — it's too bright at night and too dim in sunshine. The histogram doesn't.

What it shows

A histogram is a graph of how many pixels fall at each brightness level, from pure black on the left to pure white on the right. Its shape isn't "good" or "bad": a snow scene should lean right, a night scene left.

Clipping

• Right edge spike: highlights clipped to pure white — no detail can be recovered.
• Left edge spike: shadows blocked to pure black.

Specular highlights (the sun, glints on water) can clip; large clipped skies or bright rock usually mean you should expose less.

RGB vs. luminance

The default luminance histogram can hide a single clipped channel. Sunsets often clip red, and blue skies can clip blue, while the luminance graph looks fine. Use the RGB histogram in your camera, or the online histogram & clipping checker, which highlights clipped areas in red.

Expose to the right (ETTR)

Digital sensors record the most information in the brighter tones. Exposing as bright as possible without clipping highlights gives cleaner shadows after processing — but only in RAW, and only if you then correct the brightness in editing.

When one exposure isn't enough

If the histogram touches both edges, the scene's range exceeds the sensor's. Bracket exposures and blend them; the HDR bracketing calculator estimates how many frames you need.

In the field

Turn on highlight alerts ("blinkies") and the RGB histogram in playback. After each composition, check — it takes two seconds and saves the shot.