Photoshop

Adjust Exposure for HDR images

The Exposure dialog box is designed for making tonal adjustments to HDR images, but it works with 8‑bit and 16‑bit images. Exposure works by performing calculations in a linear color space (gamma 1.0) rather than the image’s current color space.

  1. Choose Image > Adjustments > Exposure.
  2. Set any of the following options:
    Exposure
    Adjusts the highlight end of the tonal scale with minimal effect in the extreme shadows.

    Offset
    Darkens the shadows and midtones with minimal affect on the highlights.

    Gamma
    Adjusts the image gamma, using a simple power function. Negative values are mirrored around zero (that is, they remain negative but still get adjusted as if they were positive).

    The eyedroppers adjust the image’s luminance values (unlike the Levels eyedroppers that affect all color channels).

    • The Set Black Point eyedropper sets the Offset, shifting the pixel you click to zero.

    • The Set White Point eyedropper sets the Exposure, shifting the point you click to white (1.0 for HDR images).

    • The Midtone eyedropper sets the Exposure, making the value you click middle gray.