HDR Photography Explained in a Diagram

Reddit user MacTuitui created this simple diagram (click to enlarge) explaining the idea behind HDR photography. The first low dynamic range (LDR) taken normally with a camera isn’t able to capture much of the detail found in the highlight and shadow areas of the scene. Two (or more) photographs are then taken at different exposure values to capture a wider range (the bracketing step) and subsequently combined into a single image with a high dynamic range (HDR). Since most displays aren’t capable of displaying this full range, the image needs to be tone mapped to have its appearance approximated on LDR screens.

  • L. E. R.

    My favorite is the rainbow. Helps me to calm down with those Beautiful COLORS

  • Anonymous

    Isn’t there a lot more overlap than that? A good sensor has at least 8EV of range, so the chart should show at least 4EV of overlap

  • Chris Kandel

    I think it’s more a chart to illustrate the idea of how HDR works, not so much to take into account every scenario possible.

  • Vdhamer

    The diagram explains the use of bracketed exposures well. But the key challenge is – once you have all the information from the original scene – how to map that to a limited range without just reducing the contrast. That would give muddy looking details. The solution is to locally over and underexpose the image (like you would do in a dark room: burning and dodging) while avoiding readily distracting transitions (“halos”) as much as you can.

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