Full-Array Local Dimming (FALD)

Physical Architecture and Placement

FALD differs fundamentally from edge-lit LCD displays in LED placement. Edge-lit systems position LEDs only along the screen's borders, using light guides and diffusers to spread illumination across the panel. FALD distributes LEDs directly behind the entire surface of the LCD panel, enabling light to be controlled across the full display area. This architecture requires thicker displays than edge-lit designs. FALD sets are substantially thicker than edge-lit alternatives, which can be less than 0.5 inches thin.

Zone Count and Specifications

FALD zone counts range from a few dozen to hundreds or thousands, with zone granularity varying significantly by display type and manufacturer. Some FALD monitors are specified at 384, 512, or 1,152 zones, though the true origin of these specific numbers should be verified against manufacturer documentation before relying on them as industry standards.

The number of zones directly affects performance. The Panasonic DX902 (2016), for example, implemented 512 FALD zones in a 32-column × 16-row configuration and achieved 1,250 cd/m² peak brightness when measured using UHD Alliance window sizes (a reviewer measurement, not full-screen average brightness).

Contrast and Black Levels

FALD enables higher contrast by allowing zones corresponding to dark areas of the picture to be dimmed significantly while zones under bright areas are brightened simultaneously. This targeted control produces much deeper black levels adjacent to bright highlights compared to displays without local dimming. However, unlike OLED displays, FALD cannot achieve true black levels because even when black pixels are displayed, backlight leakage allows some light through.

For context, OLED achieves an absolute black level of 0 nits and infinite contrast through pixel self-emissivity, while Mini-LED panels (which use more numerous, smaller LEDs than standard FALD) can sustain 400–900 nits or more across the entire screen. FALD and Mini-LED technologies offer advantages in bright environments and daytime viewing, whereas OLED excels in dark-room cinematic applications.

Blooming and Halo Artifacts

Blooming (also called the halo effect) is the most visible limitation of FALD technology. This artifact occurs when light from bright objects on screen spills into surrounding dimmed zones, creating a glowing halo around isolated bright elements. The mechanism is inherent to zone-based dimming: when a zone is brightened for a bright object, light inevitably bleeds beyond the zone boundaries into adjacent dimmed areas.

Blooming severity depends on dimming zone density, local dimming algorithm quality, scene complexity, and room darkness. It is most noticeable around isolated bright objects such as stars, street lights, or subtitles on dark backgrounds. Higher zone counts reduce blooming artifacts; on a 27-inch monitor, moving from 576 to 1,152 zones roughly halves visible halo area in demanding HDR scenes according to manufacturer testing (a vendor-sourced estimate, not an independently verified industry benchmark).

FALD versus Mini-LED Local Dimming

Standard FALD uses a few hundred LEDs grouped into dozens of zones, while Mini-LED displays can use 2,000 to 10,000+ tiny LEDs enabling hundreds to thousands of zones for finer control. This difference in LED count and zone granularity translates directly to blooming reduction and contrast performance.

Contrast-ratio claims for high-end systems require careful interpretation. One Mini-LED monitor manufacturer claims its high-end Mini-LED panels can reach a real-time contrast ratio up to 1,000,000:1 via 1,152–2,304 dimming zones, while native static panel contrast remains around 5,000:1. This is a vendor specification for that manufacturer's own products, not an independently measured industry figure. Real-time (dynamic) contrast with active local dimming differs substantially from native static contrast, and marketing claims in this category historically reflect best-case scenarios rather than typical user experience.

Cost and Manufacturing Trade-offs

FALD TVs have higher manufacturing costs than edge-lit designs due to substantially more LEDs and sophisticated control electronics required for independent zone dimming. The increased component count and thermal management requirements add to both the complexity and the final price point of FALD displays.