For years, traditional LCD monitors suffered from poor contrast ratios because their edge-lit backlights remained permanently on, turning blacks into a washed-out dark grey. To solve this, display manufacturers introduced Full Array Local Dimming (FALD) and Mini-LED technologies. However, these systems introduce a specific visual artifact known as blooming (or the halo effect). Our interactive FALD Blooming test helps enthusiasts evaluate local dimming algorithms, estimate zone counts, and optimize display settings in real-time.
What is Mini-LED Blooming & FALD Haloing?
A FALD or Mini-LED display places a grid of microscopic light-emitting diodes directly behind the liquid crystal (LCD) panel. Instead of illuminating the entire screen uniformly, the monitor's control board groups these LEDs into hundreds or thousands of independent local dimming zones. When rendering a dark scene with a bright object (like a cursor or stars in space), the zones behind the bright object light up, while zones in dark areas turn off completely, yielding near-infinite OLED-like contrast.
Blooming (the halo effect) occurs because even the smallest local dimming zones are still vastly larger than individual physical pixels. For instance, a 4K display contains over 8.2 million pixels, but a high-end Mini-LED monitor may only contain 1,152 or 2,304 physical dimming zones. When a small white object (like a cursor) crosses a dark region, the active zone illuminates a square area that extends beyond the cursor's edge. This active backlight bleeds through the LCD panel, creating a glowing "fog" or "halo" around the cursor.
How to Use This Blooming Test Effectively
To get the most accurate evaluation of your monitor's local dimming zone algorithms, follow these benchmarking guidelines:
- Darken Your Environment: Turn off all ambient room lights. GtG light bleed and blooming halos are difficult to detect under bright office lighting.
- Enter Fullscreen Mode: Click the "Enter Fullscreen" button (or press F11). Any surrounding browser window borders or bright UI elements will force surrounding zones to stay lit, skewing the test.
- Observe Zone Transitions: Set the motion pattern to "Bouncing Ball" and check for lag. In cheaper monitors, you may see the backlight zone "chasing" the moving object, leaving a temporary trail of light.
- Use the Alignment Grid: Toggle "Show Grid". By watching which grid boxes light up as the cursor moves, you can visually count and determine the horizontal and vertical resolution of your display's backlighting matrix.
How to Minimize Blooming on Your Display
While blooming is a physical limitation of LCD panel matrices, you can reduce its severity using these settings tweaks:
- Adjust Local Dimming Aggressiveness: Most monitors offer "Low", "Medium", and "High" local dimming options in their OSD. "High" yields the deepest blacks but causes aggressive blooming. "Medium" or "Low" balances contrast while blending the halo edges smoothly.
- Lower Overall Backlight Brightness: Running a display at 100% SDR/HDR brightness in a dark room makes blooming extremely harsh. Drop your brightness to comfortable working levels (e.g. 120–150 nits).
- Add Bias Lighting: Placing a gentle LED strip behind your monitor creates ambient wall glow. This increases your eye's pupil contraction, making blooming halos look much less visible to the naked eye.
Frequently Asked Questions about MiniLED Local Dimming
Is OLED completely immune to blooming?
Yes. OLED (Organic Light Emitting Diode) displays use self-emissive pixels. Every pixel creates its own light and can turn off completely. Since there is no backlight bleed or zones, OLED displays feature perfect black boundaries with zero blooming.
Why does blooming look worse when viewed at an angle?
Most high-end monitors use VA or IPS LCD panels. These panels block light using liquid crystal alignment, which is optimized for straight-on viewing. When viewed from the side, the panel's native contrast drops, allowing backlight light leakage to bleed through more easily, amplifying the halo appearance.
How many zones does a good MiniLED monitor need?
For a standard 27-inch 4K monitor, at least 576 zones are recommended for decent HDR. Monitors with 1,152 or 2,304 zones offer significantly tighter control, reducing blooming artifacts in text and dark video games to almost imperceptible levels.