Bloom is the technical name for a glowing effect in imagery. It creates a feathered light glowing around an object. Bloom can be accomplished in Blender. The process for adding Bloom and Glare in Blender differs in Eevee and Cycles.

A side by side comparison of a scene with and without bloom in Eevee.

We will start with Eevee, but click here to jump to the Cycles part. For more on Blender lighting in general, see my complete guide to lighting in Blender.

How to Add Bloom in Eevee

Blender’s realtime render engine is called Eevee and it’s capable of adding a glow or bloom effect very easily. The effect will be based off the strength of emissive materials in the scene.

Quick Tip: Bloom in Eevee

How to add bloom in 25 seconds

To activate bloom (glow) in Eevee, go to the Render Properties panel. Scroll to the tab labeled “Bloom” and check the box.

A glow effect will now be visible around emissive materials in renders and render previews.

The effect will be stronger on materials with a higher emission strength.

Bloom Settings (Eevee)

When bloom is activated in the render properties, several settings appear.

Threshold

The threshold is what strength of emissive material will be affected by the bloom. If it is set to 1, only materials with an emission strength above 1 will have the glow effect.

The bloom settings are displayed in the render properties panel when Eevee is set as the render engine.

Knee

The knee setting adjusts the transition between the areas that are below and above the threshold.

Radius

The radius is how far the bloom effect spreads. Higher values spread farther.

Color

A color can be added to the bloom effect. The default color is white and this will generally be what is used. In this example image, a red color has been added to the bloom.

Having a color other than the emission may be an effect you want…or not.

A red bloom glow effect has been added to an object with green emission to demonstrate how color can be added to bloom in Eevee.

Intensity

The intensity setting is how powerful the glowing bloom effect will appear in Eevee. A higher intensity will be more noticeable.

Blender's Bloom intensity is compared at values of .25, .75 and 2.

The intensity slider has a range of zero to one, but higher values can be entered manually.

Clamp

Clamp places a limit on how strong any single bloom pixel can be. If we have a scene where certain materials are very bright, we can limit the intensity effect with a clamp.

Here’s a link to the Blender manual’s documentation on the Eevee Bloom effect.

Creating Glow / Bloom in Cycles

Quick Tip: Glare Node for Cycles Glow

Glare Node explained in 26 seconds

Although we can’t create a bloom effect in Cycles the same way we can in Eevee, we are able to use the compositor and the glare node to get a similar effect.

Using the compositor to achieve a glow effect in Cycles can be set up before or after we render a single image.

For animations, the compositor nodes should be set up before rendering so they affect all frames of the animation.

Adding a Glare Node in the Compositor

To add glare to a render in Cycles, we go to the compositor. We can find the compositor by changing to the compositing workspace.

The compositing workspace is highlighted in Blender's workspace menu bar.

In order to use nodes, we have to ensure the “Use Nodes” box is checked in the compositor.

The "Use Nodes" check box in Blender's compositor is highlighted.

With “Use Nodes” checked, we should see a node setup that looks like this:

The default node setup in the compositor displays a render layers node connected to a composite output node.

To add glow to a rendered image in the compositor, press “Shift + A” to add a node. Search for a glare node (found in the filter category).

The add node menu is open in the Blender compositor and the glare node is highlighted in the filter category.

Place the Glare Node between the render layers node and the composite output node.

The glare node is placed between the render layers node and the composite output node in the Blender compositor.

The best way to view the effects of the glare node in the compositor is to open another editor screen, change it to an Image Editor and select “Render Result” from the image selector at the top.

Adding Multiple Glare Types

We can add multiple glare types by adding multiple glare nodes. Place a second glare node between the first glare node and the composite output node. Use one glare node for each type of glare we want to add.

Glare Node Settings

The Glare Node in Blender’s compositor has several settings to adjust how the glare appears in the render. We will cover those settings here.

Glare Type

The first setting is glare type and it defaults to “Streaks.” Other options include Ghosts, Fog Glow and Simple Star. Here are examples of each, exaggerated for demonstration.

The four glare types in Blender's compositor are compared: Ghosts, Streaks, Fog Glow and Simple Star.

While Fog Glow may be the simplest and closest to the bloom effect used in Eevee, you can see other types give us some interesting effects. Of course the intensity of these filters can be adjusted.

The glare type chosen will determine which other options are available. Here are the settings displayed for each glare type.

The glare node settings are compared for each type of glare. Each glare type has its own settings.

Glare Quality

Glare Quality is the box which defaults to “Medium” in the above images. This is the resolution of the glare and available options are: High, Medium and Low. Higher quality means a more defined effect with higher resolution.

Iterations

Iterations is an option for all glare types except fog glow. This is how many times the glare filter will be applied. The value can be as high as five. The more iterations, the more intricate the effect will be.

Human Generator is an add-on that creates human characters inside of Blender.

Mix

The glare effect is mixed with the original image by the glare node. The “Mix” setting adjusts how much of the original image is visible compared to the filter effect.

The mix setting range is from -1 (full original image) to 1 (full glare effect). Zero will be a 50/50 mix of the image. Here are some comparisons of glow mixes for reference:

Different mix values from the glare node in the Blender compositor are compared. Values range between -1 and 1.

Threshold

As with the bloom effect in Eevee, the glare node can have a minimum threshold. Pixels with emission strength below the threshold will not have the glow effect applied to them.

Other Glare Settings

As you see there are a handful of other settings on the glare node. They are mostly self-explanatory. If you experiment with them, you may see small differences in the glare effect on your render.

Here is the Blender documentation on the glare compositing node.

Final Thoughts

Although the methods of adding a glow effect are different in Eevee and Cycles, it can be done in both. I have a lot of other helpful content on this site, so please have a look around.

I also have a YouTube channel full of Blender tutorials and would love to have you as a subscriber. Take care and stay creative!

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