Refresh Rate
Refresh rate measures how many times per second an LED display updates its image, expressed in Hertz (Hz). Broadcast and film applications require 3,840Hz or higher to eliminate visible flicker in camera recordings, while 1,920Hz is acceptable for live-only events without video capture.
Understanding LED Display Refresh Rate
Refresh rate indicates how frequently an LED display redraws its image. Unlike consumer displays that refresh at 60Hz or 120Hz, professional LED video walls operate at much higher refresh rates, typically 1,920Hz to 7,680Hz, to accommodate camera capture requirements.
Why LED Displays Need High Refresh Rates
LED panels use multiplexed driving, meaning not all LEDs are illuminated simultaneously. The display rapidly cycles through rows or sections of LEDs to create the appearance of a continuous image. This scanning process creates potential issues for camera sensors that capture individual frames.
Refresh Rate and Camera Capture
Modern cameras use electronic shutters that capture images in fractions of a second. If the camera exposure time overlaps with the LED display scan cycle, the resulting image may show:
- **Horizontal bands** where some rows are lit and others are dark
- **Flickering** as the relative timing shifts between frames
- **Color shifting** if RGB LEDs update at different times
High refresh rates minimize these artifacts by completing more display cycles during each camera frame.
Recommended Refresh Rates by Application
1,920Hz: Suitable for live events, digital signage, and applications without video recording.
3,840Hz: Standard for broadcast television, corporate events with video production, and general filming.
7,680Hz: Required for high-speed cameras, slow-motion capture, and premium broadcast applications.
Relationship with Scan Ratio
Refresh rate and scan ratio work together to determine display performance. A 1/16 scan panel needs higher base refresh rates than a 1/4 scan panel to achieve equivalent camera-safe performance. Higher scan ratios (1/2, 1/4) inherently support higher effective refresh rates.
Processor and Receiving Card Impact
Achieving high refresh rates requires compatible receiving cards in each panel and proper processor configuration. Some older receiving cards cap at 1,920Hz regardless of panel capability. Always verify the entire signal chain supports your required refresh rate.
Frequently Asked Questions
Why does refresh rate matter for video production?
Camera sensors capture images differently than the human eye. At lower refresh rates, cameras may capture the LED display mid-scan, creating visible banding or flickering in recorded footage. High refresh rates (3,840Hz+) ensure each camera frame captures a complete display cycle.
What refresh rate do I need for my event?
For live events without video capture, 1,920Hz is typically sufficient. For broadcast, film, or events with professional video recording, specify 3,840Hz or higher. Some high-end productions require 7,680Hz for slow-motion footage.
How does refresh rate affect power consumption?
Higher refresh rates require more processing power and generate slightly more heat, but the impact on overall power consumption is minimal compared to brightness settings. The difference between 1,920Hz and 3,840Hz is typically 5-10% additional power.
Related Terms
Scan Ratio
ProcessingScan ratio describes the LED driving method that determines how many pixel rows illuminate simultane...
Gray Scale
PerformanceGray scale refers to the number of brightness levels each LED pixel can display, determined by the b...
LED Processor
ProcessingAn LED processor is the video processing device that receives input signals (HDMI, SDI, DisplayPort)...
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