Photo Histogram Viewer

Reading a histogram

The horizontal axis runs from pure black (left) to pure white (right); the height shows how many pixels sit at each brightness. A histogram crammed against the left edge means crushed shadows; a spike at the right edge means blown highlights that no editing can recover. The colored curves show the red, green, and blue channels — a single channel touching the right edge means that color is clipping even if the image looks fine.

Frequently asked questions

Is there a “correct” histogram shape?

No — a night scene should lean left, a snow scene right. The histogram is a tool for spotting unintentional clipping, not a target shape.

What is “expose to the right”?

ETTR means exposing as bright as possible without clipping highlights, then darkening in post. It maximizes signal-to-noise in RAW files. This viewer's highlight-clipping percentage tells you how much headroom you had.

Why does luminance weight green so heavily?

Human eyes are most sensitive to green, so luminance is computed as 0.2126 R + 0.7152 G + 0.0722 B (the Rec. 709 weights this tool uses).