Skip to main content
Rendering artifactPost Processing

Auto-Exposure Pumping

Stabilize exposure metering when bright and dark objects enter or leave the camera view.

auto exposureeye adaptationpost processingcameralighting

What you're seeing

The whole frame brightens or darkens abruptly as small bright or dark regions enter and leave the view.

Likely causes

  • Bright objects near the screen edge have too much influence on metering.
  • Low Percent or High Percent prioritizes unstable brightness ranges.
  • Speed Up and Speed Down do not match the intended camera response.

Check in this order

  1. 01Open HDR Eye Adaptation and watch target, actual, and final EV100 while reproducing the change.
  2. 02Enable histogram debug and identify bright or dark pixels that should not drive metering.
  3. 03Use a center-weighted Exposure Metering Mask to reduce edge influence.
  4. 04Tune Low Percent, High Percent, Speed Up, and Speed Down for the expected camera movement.

Views and commands

Exposure visualization

Show > Visualize > HDR (Eye Adaptation)

Shows the luminance histogram and target, actual, and final EV100 values.

Histogram debug

r.EyeAdaptation.VisualizeDebugType 1

Marks pixels outside the configured exposure histogram range.

Post Process setting

Exposure > Exposure Metering Mask

Weights screen regions so edge highlights have less influence.

Adaptation transition

r.EyeAdaptation.ExponentialTransitionDistance 1.5

Restores the documented default transition distance in f-stops for comparison.

Epic documentation

Related guides

Unreal Directive is free and ad-free.

If it saved you time, you can help keep it that way.

Donate