Bloom / glow pass
A blurred copy of the brightest parts added back to make intense light spill softly beyond its edges.
See it
What it is
A bloom or glow pass isolates the brightest pixels, blurs them, and adds that soft light back around the source. It imitates light scattering through a lens, sensor, atmosphere, or eye, so an intense highlight appears to spill beyond its sharp boundary. Game engines run the same treatment as a post-process called bloom, and Unreal Engine ships it in the default post-process stack.
Reach for it on neon, fire, emissive graphics, reflections, and hot specular highlights. Build it from the graded image so the threshold selects what is genuinely bright, then tune the radius to the source: small lamps need a tighter halo than a blown window.
Gotcha: a low threshold turns the entire frame milky and lowers contrast. Bloom should grow from bright sources, not sit equally on skin, shadows, and text. Work in a high-bit-depth linear pipeline when possible, and recheck highlights after the display transform for clipping and banding.
Ask AI for it
Build a bloom pass in 32-bpc Adobe After Effects with the Glow effect set to Glow Based On Color Channels. Start with Glow Threshold at 80 percent, Glow Radius at 30 pixels, and Glow Intensity at 0.6, then tune the radius to the source size. Keep skin, shadows, and ordinary white text below the threshold, preserve the sharp original underneath, and check the final Rec.709 transform for clipped highlights or banding.