Panel & Backlight
Blooming Test (Mini-LED)
A bright object on black to judge local-dimming halos.
▶ Start full-screen testMoving dot← / → or tap the sides to switch · Esc to exit
How to use
- 1Dim the room and click Start.
- 2Move your cursor / finger to drag the bright dot around the black field.
- 3Watch for a glowing halo (bloom) around the bright object.
- 4Use → for the zone sweeps: count how often the halo jumps as the square crosses the screen — that's roughly the number of dimming zones across (or down).
- 5Press Esc to exit.
FAQ
Why does blooming happen?
Local-dimming backlights have a limited number of zones. A small bright object lights its whole zone, so some glow spills into the surrounding black area.
Does OLED have blooming?
No. Every OLED pixel makes its own light, so a bright object on black has no backlight zone to spill out of. Blooming is specific to LCDs with local dimming, including Mini-LED.
How do I reduce blooming?
Most local-dimming displays let you set how aggressive the dimming is. A lower setting shrinks halos but lifts blacks; a higher one deepens blacks but blooms more. A little light in the room also makes halos less noticeable than a pitch-dark one.
Tips
- Run it in a dark room; blooming around the bright dot is hard to see with the lights on.
- More dimming zones = less bloom. OLED shows essentially none.
Related tests
Dead Pixel TestFull-screen solid colors to find dead, stuck, and bright pixels.Open test→Backlight BleedReveal LCD backlight leakage and IPS glow in a dark room.Open test→Brightness UniformityA 50% gray field, a 9-zone grid and a panning gray to spot uneven backlighting.Open test→Burn-in TestFull-screen fields and a checkerboard to reveal OLED burn-in.Open test→
Related guides
Learn more about what this test reveals and how to act on the results.
Mini-LED vs OLED: Which Is Better for You?Brightness and burn-in resistance versus perfect blacks and zero blooming — the real trade-offs between Mini-LED and OLED, and who each suits.How to Test a New TV for Dead Pixels and UniformityUse your TV's browser or a phone to run solid-color and gray tests that reveal panel defects and dirty-screen effect.What Is IPS Glow (and How to Reduce It)?That silvery corner shine on IPS panels is a viewing-angle effect rather than a defect — how to tell it from bleed, and how to reduce it.HDR Explained: What Makes a Display Actually HDRMost monitors labeled 'HDR' aren't. Here's what real HDR needs — peak brightness, local dimming, contrast and wide color — and how to check.