Enrico Marega Interactive photography course
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The histogram and ETTR

The camera screen can fool you, the histogram can’t. It’s a graph of how many pixels there are at each brightness level: black on the left, white on the right.

1Simulator

Read the histogram

Change the exposure and watch the graph shift. With the warnings on, blown highlights flash red and blocked shadows flash blue.

2Simulator

ETTR: expose to the right

Two ways to reach the same photo: expose normally and brighten later, or expose to the right and darken later. Look at the noise in the shadows.

There’s no perfect histogram

1Simulator A night photo will have its graph piled up on the left, a beach in summer on the right, and that’s fine. What matters are the edges: if the graph is squashed against the right edge you have blown highlights, with no detail; against the left one, blocked shadows.

1Simulator Every camera can show the histogram and make clipped areas flash when you review the photo: on Nikon it’s the Highlights option among the playback display options, on Canon the Highlight alert; on Sony, Fujifilm and Ricoh you’ll find it among the playback display settings.

2Simulator ETTR (Expose To The Right) takes advantage of a property of the sensor: bright areas have less noise. If you shoot RAW, expose as brightly as you can without blowing the highlights and then bring the exposure back down in post-processing: the shadows will be cleaner.

Key points

  • Horizontal axis: from black (left) to white (right). Height: how many pixels have that brightness.
  • Graph squashed to the right = blown highlights. To the left = blocked shadows. In between, any shape is fine.
  • ETTR: in RAW, expose as brightly as you can without clipping, then darken in post: less noise in the shadows.

Try it yourself

Turn on the histogram and the highlight warning in the playback menu. Photograph a sky with white clouds and raise the compensation until the clouds start to flash: the shot before that is your ETTR.

Post the result and tag me @enrico.marega, or send it to me by DM: I’d love to see how you tackled it.

Quick check

The histogram touches the right edge with a tall peak. What does it mean?
With the ETTR technique, what do you do in post-processing?