LED scan rate decoded: 1/8 vs 1/16 vs 1/32 and what your supplier won't tell you
Scan ratio is the LED spec hidden behind the headline refresh-rate number. Here's what 1/8, 1/16, 1/32 and 1/64 scan actually mean for image quality and on-camera fidelity.
If you read only one number on an LED cabinet datasheet, the industry hopes you read the refresh rate. “3,840 Hz” looks reassuring next to a competitor’s “1,920 Hz.” It is also one of the easier numbers to game.
The number that actually decides whether a wall reads cleanly on a broadcast camera, holds grayscale at 1% brightness, and survives a fast-shutter slow-motion replay is the scan ratio — printed two lines further down the same datasheet, often without explanation.
This post is the reference for what scan ratio means, why it matters, and how to specify it.
What scan ratio is, in one paragraph
An LED module is electrically organised in rows. Lighting every row at full brightness simultaneously would draw too much current and waste energy on still imagery, so driver ICs cycle through the rows: light row 1, switch off, light row 2, switch off, and so on. The scan ratio is the proportion lit at any one moment. A 1/16-scan module lights one row in every sixteen at a time. A 1/32-scan module lights one row in every thirty-two.
A higher denominator (1/32, 1/64) means each row is lit for a smaller fraction of any given moment, but — under a typical PWM scheme — the driver IC can divide its time budget into shorter, more frequent pulses per row. That sounds like a downgrade — and for raw brightness, it is — but it is what allows the driver to deliver cleaner low-grayscale fidelity and reduce camera-visible banding. The exact behaviour depends on the driver IC’s PWM architecture (standard PWM vs PWM+ vs energy-saving), which is why naming the IC matters as much as quoting the scan ratio.
Why headline refresh rate alone is misleading
A driver IC running at 3,840 Hz refresh on a 1/16-scan cabinet refreshes each LED 3,840 times per second, but the LED is lit for roughly 1/16 of each cycle. A 1/32-scan cabinet at the same 3,840 Hz lights each LED for roughly 1/32 of each cycle — a shorter pulse per cycle that, under most PWM schemes, the driver delivers as more frequent shorter pulses across the cycle. The exact pulse distribution is a function of the driver IC’s PWM architecture, not the headline scan ratio in isolation.
For human-eye viewing, the two are typically indistinguishable. For a camera with a fast shutter, the 1/32 cabinet usually wins, because — depending on the driver IC’s PWM architecture — the shutter is more likely to open during an “on” pulse rather than coincide with the longer dark gaps a 1/16 cabinet leaves between pulses. The exact behaviour is driver-IC-dependent, which is why the question to ask is always “what scan ratio and what driver IC” — never one alone.
This is why broadcast engineers ask about scan ratio first and headline refresh second. A 1,920 Hz / 1/32 cabinet typically outperforms a 3,840 Hz / 1/16 cabinet on camera even though the headline number is half.
Scan ratios in commercial cabinets, by application
| Application | Typical scan | Why |
|---|---|---|
| Outdoor billboard, bright daylight | 1/4 or 1/8 | Maximum brightness per watt; cameras rarely involved. |
| Stadium perimeter, score and ribbon | 1/16 | Compromise between brightness and broadcast capture. |
| Indoor retail, corporate lobby | 1/16 or 1/32 | Lower brightness draw, lower flicker visibility. |
| Broadcast studio, behind-the-anchor | 1/32 or 1/64 | Camera-grade refresh, clean grayscale. |
| Virtual production / XR volume | 1/32 or 1/64 | Cinema-camera shutter compatibility. |
| COB fine-pitch ≤ P1.5 | 1/64 | Low-grayscale colour fidelity at 0–5% brightness. |
Notice what is not in this table: a magic “best scan ratio.” 1/64 on an outdoor billboard is a waste of money. 1/8 in a broadcast studio is a service ticket waiting to happen. The right answer is application-specific and is decided by the camera shutter range, ambient brightness and viewing distance — not by which number sounds biggest in marketing.
How driver IC and scan ratio interact
The reason every cabinet does not ship at 1/32 is that pushing a high scan ratio requires a driver IC capable of holding 16-bit grayscale at the shorter pulse width. Not every IC can do this.
The reference table:
| Driver IC | Maximum scan | Bit depth | Typical use |
|---|---|---|---|
| ICN2266 | 1/16 | 14-bit | Budget indoor, no broadcast |
| ICN2153 | 1/32 | 16-bit | Cost-down V-SPEC alternative |
| MBI5153 | 1/32 | 16-bit | Professional / broadcast standard |
| MBI5252 | 1/64 | 16-bit (PWM+) | COB fine-pitch, broadcast |
| MBI5353 | 1/64 | 14-bit + dithering | Energy-saving outdoor |
| FM6353 | 1/32 | 14-bit | Outdoor billboard, energy-saving |
A “professional broadcast LED” cabinet quoted with an ICN2266 driver is not professional broadcast LED. It is a budget cabinet relabelled. The scan-rate cap on the IC is the giveaway.
The full driver-IC reference, with PWM type and Aurora’s notes on real-world performance, lives at /resources/performance-benchmarks.
How to ask the question on an RFP
If you are writing a tender, the line item to insert is:
Driver IC family must be specified by name. Scan ratio at full image data must be 1/32 or finer for any application where camera capture is anticipated; 1/64 for broadcast and virtual production. Quotations stating only headline refresh rate without naming the driver IC and scan ratio will be returned for clarification.
Suppliers who can answer that question in one paragraph are credible. Suppliers who answer with marketing copy and “high refresh chip” are not.
Aurora’s stack
Aurora publishes the driver IC and scan ratio for every range on the Performance Benchmarks page. The summary:
- LUX (fine-pitch indoor / broadcast): MBI5252, 1/64 scan, 16-bit.
- V-SPEC (standard professional): MBI5153, 1/32 scan, 16-bit.
- GSR (price-led outdoor): ICN2153, 1/32 scan, 16-bit.
Verified at factory acceptance using the in-house LED Analyser MLED test system.
Talk to us and bring your camera package and shutter range. We’ll quote against your actual application — not the headline number.
Frequently asked questions
What is LED scan ratio?
Scan ratio (sometimes called scan rate) is the proportion of LED rows in a module lit at any one moment. A 1/16-scan cabinet lights one row in every sixteen at a time and cycles through all sixteen rows so quickly the eye sees a continuous image. A 1/32-scan cabinet lights one row in every thirty-two. Under a typical PWM scheme, the higher denominator generally allows the driver IC to deliver shorter, more frequent pulses per row, which is why 1/32 cabinets typically read cleaner on camera than 1/16 cabinets at the same headline refresh figure — but the exact behaviour depends on the driver IC's PWM architecture, so always read scan ratio and driver IC together.
Is a higher scan ratio always better?
Lower-denominator scan (1/8) means each LED row is lit a bigger fraction of the time, which gives more headline brightness for less power but at the cost of camera-visible banding. Higher-denominator scan (1/32 or 1/64) gives cleaner camera capture and better grayscale at low brightness, at the cost of more demanding driver-IC selection. Pick the scan ratio that fits the application: 1/8 for outdoor billboard, 1/16–1/32 for professional indoor, 1/32–1/64 for broadcast and fine-pitch.
What does a '3,840 Hz / 1/16 scan' spec actually mean?
It means the cabinet refreshes every LED 3,840 times per second, but only one row in sixteen is lit at any one moment. On a fast-shutter camera that opens during a 'dark' phase of the cycle, you get scan-line banding regardless of the headline 3,840 Hz number. The same cabinet built at 1/32 scan with the same driver IC would visibly outperform it on broadcast camera.
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