Quick answer: Bloom is set in a Post Process Volume under Lens > Bloom.
- Too much glow: lower Intensity (the default is 0.675) and lower the emissive values in your materials.
- Soft haze over everything: raise Threshold from its default of -1 to around 1, so only bright parts glow.
- No bloom at all: check that Intensity is above 0, that Show > Post Processing > Bloom is ticked, and that your emissive is bright enough.
- Glow changes as you look around: that’s auto exposure. Lock it first.
How bloom works
Bloom spreads light from bright pixels into their neighbours, like a camera lens. It depends on how bright a pixel is after exposure. That’s why the same emissive material can glow a lot in a dark scene and barely at all in daylight.
Too much bloom
- Add a Post Process Volume and tick Infinite Extent (Unbound).
- Under Lens > Bloom, lower Intensity. Try 0.3.
- Lower the emissive strength in your materials. A screen or LED often needs only 1 to 10. Very high values make huge halos.
- If bloom still pumps as you move, lock auto exposure. See fixing auto exposure.
Everything has a soft haze
In UE5, Threshold defaults to -1, which means every pixel blooms a little. That looks natural in many scenes, but it can make stylised or clean scenes look foggy. Tick Threshold and set it to around 1, then raise it until only the brightest parts glow.
Bloom is not showing
| Check | Where |
|---|---|
| Intensity is above 0 | Post Process Volume > Lens > Bloom |
| The volume affects the camera | Tick Infinite Extent (Unbound) |
| The bloom show flag is on | Viewport Show > Post Processing > Bloom |
| Bloom is enabled for the project | Project Settings > Rendering > Default Settings > Bloom |
| The emissive is bright enough | Raise it, or lower exposure so it stands out |
| Scalability isn’t hiding it | Test with Post Processing set to Epic in Engine Scalability Settings |
Standard or Convolution?
Standard bloom is cheap and fine for games. Convolution uses an image of a lens glare (Convolution Kernel) to make realistic streaks and halos. It looks great in cinematics, but it costs much more GPU time, so test it on your target hardware before using it in gameplay.
Rings, ghost circles and streaks across the screen come from Lens Flares, a separate setting in the same Lens section. Grime that shows up around bright light is the Dirt Mask.
FAQ
Why does bloom look different in the editor and in Play?
Usually exposure. The viewport may use a fixed exposure while the game uses auto exposure. In the viewport’s Lit > Exposure menu, tick Game Settings.
Can I make one object glow without bloom everywhere?
Raise the Threshold so only very bright pixels bloom, then make that object’s emissive brighter than everything else.
Does bloom cost performance?
Standard bloom is cheap. Convolution bloom is expensive, especially at high resolutions.