Flicker Free

In the age of LED lighting, we expect performance: long life, low energy, sleek design. But one critical factor still too often slips through the net—flicker.

Whether it’s an obvious strobe or a subtle shimmer, flickering light is more than a nuisance. It can compromise wellbeing, reduce concentration, distort camera footage, and in some cases, pose a serious health or safety risk.

This explainer breaks down what flicker is, why it happens, and how to design systems that eliminate it.

A large, round, glowing bluish-purple object with evenly spaced horizontal dark lines across it, set against a dark background. Illustrates the problem solved by flicker free LED lighting

What Is Light Flicker?

If you’ve ever noticed lights subtly pulsing—or worse, flashing—it’s usually due to fluctuations in power delivery. These changes cause the LED to switch on and off rapidly, creating the appearance of flicker. In many cases, this effect is too fast to detect consciously, but our brains and eyes still respond.

The frequency of this fluctuation, measured in Hertz (Hz), determines how visible or disruptive it is. As the frequency increases into the kilohertz range, flicker becomes less perceptible—but the potential impact doesn’t disappear entirely.

Why Flicker Free LED Lighting Is So Important

 

Even when flicker isn’t visible, it can still have profound effects on people and environments.

Visual Discomfort

  • Eye strain and fatigue

  • Difficulty concentrating

  • Headaches and migraines

Health Risks

  • Neurological issues in sensitive individuals

  • Triggering seizures in those with epilepsy

Productivity Impact

  • Reduced workplace efficiency

  • Slower learning and increased distraction in educational settings

  • Impaired recovery in healthcare environments

 

Safety Hazards

  • Stroboscopic effects in industrial settings can make moving machinery appear slow or stationary—an obvious safety concern.
The Effects of Light Flicker

Calculating flicker metrics

Flicker Metrics

Flicker-Free Lighting and Content Creation

As digital content becomes central to how brands communicate, lighting that works on camera is no longer optional.

Flickering LED lighting causes a range of video issues:

  • Banding or rolling flicker in videos—even when the flicker is invisible to the naked eye

  • Uneven exposure or colour pulsing on camera sensors

  • Distracting effects in slow motion or high-frame-rate footage

  • Loss of professional quality in product videos, livestreams, and social media content

These problems affect a wide range of industries:

  • Retail & advertising: Flicker can undermine the look of digital signage or in-store displays captured on mobile
  • Broadcast & studios: Lighting must be calibrated for flawless, flicker-free results at any frame rate
  • Corporate & events: Conference rooms, trade shows, and webinars now double as video sets—lighting needs to support that
  • Transport & public spaces: On-camera lighting quality matters for passenger-facing screens, signage, and promotional materials

With flicker-free lighting, brands get:

  • Clean, stable footage across all devices and frame rates

  • More creative flexibility (including slow-mo, drone, and handheld footage)

  • Better looking content on social platforms, where every frame counts

  • A more premium, trustworthy aesthetic for digital storytelling

Put simply: if your lighting will ever appear on video, flicker-free performance is a non-negotiable.

A brightly lit cosmetics store with modern displays, colorful signage, and makeup products arranged neatly on shelves and counters. The ceiling uses flicker free LED drivers for excellent illumination quality

Why Do LED Lights Flicker?

In most cases, flicker in LEDs doesn’t come from the LED itself—it comes from the driver.

Common causes include:

  • Poor-quality LED drivers that can’t stabilise output

  • Incompatible dimming systems, especially at lower levels

  • Low-frequency PWM dimming

  • Mains voltage ripple passed through to the LED

Solid-state LED lighting may be the energy-efficiency gold standard, but flicker can still undermine the system if driver quality and dimming aren’t properly considered.

Pulse width modulation duty cycles

A graph showing voltage vs. time for pulse-width modulation, with four bars illustrating 0%, 25%, 50%, 75%, and 100% duty cycles, and the corresponding average voltage indicated for each.

How to Achieve Flicker Free LED Lighting

The good news: flicker free LED lighting can be achieved with smart design and quality components.

Use a High-Quality Driver

Look for:

  • Low ripple current output

  • High-frequency modulation (typically >25 kHz)

  • Two-stage power factor correction (PFC) to stabilise output

  • Compliance with IEEE 1789 guidelines for safe flicker limits

Adding a capacitor to buffer ripple is one method, but beware—poor-quality capacitors can degrade over time and reduce reliability.

Choose the Right Dimming Approach

Avoid systems that introduce low-frequency modulation at dimmed levels. Opt for:

  • High-frequency PWM dimming (above human flicker sensitivity thresholds)

  • Drivers tested to maintain low flicker at all brightness levels

Select an Intelligent Control Protocol

DALI (Digital Addressable Lighting Interface) is a robust, digital lighting control system that supports flicker-free performance:

  • Devices can be assigned individual or group addresses

  • Two-way communication allows devices to report faults or status

  • Power and data run through the same pair of wires—simplifying installation

DALI allows precise control and reliable dimming without introducing ripple or flicker artifacts.

Validate with Real-World Testing

  • Use flicker meters or slow-motion video to confirm performance

  • Request flicker percentage and modulation depth figures from manufacturers

  • Make sure products are tested and certified to meet flicker safety standards

Specification tips for a flicker free LED lighting project

Lighting professionals can take some steps to reduce their chances of specifying solid-state
lighting products that flicker. Be wary of products advertised as AC-LEDs. The simpler circuit design, lack of a driver, and consequently, low price may seem attractive, but some AC-LEDs can produce up to 40% flicker at full output.  At dimmed levels, the flicker percentage can be even higher.

Also, ensure that your driver supplier/specifier understands flicker and how this is affected by the driver. Trusted advice is key to find the right balance between cost and performance and most importantly, ensuring the best quality of light for any installation.

Visit our products page for LED drivers that power flicker-free LED lighting

The DALI-E1A1 Series is a white LTECH LED driver featuring technical specs, certification logos, and a wiring diagram on its surface, designed for LED lighting systems.

Flicker-free lighting isn’t a luxury—it’s a requirement for modern spaces that prioritise wellbeing, safety, and visual performance.

Whether you’re lighting a classroom, factory floor, train platform or TikTok set, flicker-free systems:

  • Protect health

  • Improve safety

  • Enable better content

  • Deliver more professional, consistent lighting environments

And if your lighting is going to be seen on camera—it better be flicker-free.

Ultimately, the key to achieving flicker-free performance lies in selecting a high-quality LED driver—one that minimises output ripple and delivers consistent current. Designers should collaborate closely with driver manufacturers and suppliers to ensure compatibility across the entire system, including the luminaire design, insulation, control protocols, and the specific demands of the application. A well-matched, carefully specified driver isn’t just a technical detail—it’s central to the long-term success of the lighting installation.