Why Do LED Light Flicker on Video and Camera?

One persistent issue that photographers, videographers, and even casual users often encounter is the flickering of LED lights when captured on video or camera footage. The phenomenon of LED light flickering can be frustrating and detrimental to the quality of visual content. It manifests as rapid fluctuations in brightness or a pulsating effect, which can be distracting, visually unappealing, and even pose health risks.

In this blog, we will delve into the reasons why LED light flicker on video and camera footage. We will explore the technical aspects of LED lights, including their operation and the factors that contribute to flickering. Furthermore, we will discuss the effects of LED light flickering on video and camera footage, highlighting the challenges it poses for professionals in the field.

What Causes The Flickering Effect In The Video?

The major factors contributing to LED light flicker on video and camera are:

Incompatibility with camera frame rates

LED lights and cameras operate on different frequencies. The frame rate of a camera refers to the number of individual frames captured per second. If the frequency of the LED light’s on/off cycles does not align with the camera’s frame rate, flickering can occur.

For example, if the LED light frequency is not a multiple or fraction of the camera’s frame rate, there will be a mismatch, resulting in flickering on the captured footage.

Voltage fluctuations

LED lights are sensitive to changes in electrical supply voltage. Fluctuations in voltage can occur due to various factors, including power grid irregularities, load changes, or incompatible dimming systems. These voltage variations can cause the LED lights to flicker as the current flowing through them fluctuates, resulting in inconsistent brightness levels.

Pulse-width modulation (PWM)

PWM is a commonly used technique to control the brightness of LED lights. It works by rapidly turning the LED on and off at a high frequency while varying the width of the pulses. However, if the PWM frequency is low, it can become visible on video footage as flickering, especially when the camera’s exposure settings or shutter speed are not synchronized with the PWM frequency.

Dimming controls

LED lights are often equipped with dimming capabilities, allowing users to adjust the brightness levels. However, not all dimming controls are compatible with LED lights, leading to flickering issues. Certain dimming techniques, such as phase-cut dimming or trailing-edge dimming, may cause inconsistencies in the electrical current supplied to the LEDs, resulting in flickering.

Also read: Do LED Strip Lights Consume a Lot of Electricity?

Different types of LED light flickering

LED light flickering can manifest in various ways, depending on the underlying causes. Some common types of flickering include:

• Regular Pulsations, where the light intensity fluctuates rhythmically.
• Random Flickering, which occurs unpredictably.
• Rapid On/Off cycling, where the light rapidly switches on and off.

Effects of LED Light Flickering on Video and Camera Footage

Visible flickering and its impact on video quality

• Flickering LED lights can create noticeable variations in brightness levels throughout the footage, leading to an inconsistent and distracting visual experience.
• These fluctuations in lighting can result in a lack of uniformity, making it challenging to achieve a professional and polished look in video recordings.
• The presence of flickering can be particularly problematic when capturing events, interviews, or scenes with rapid motion, as it can cause distortion and hinder the overall clarity of the footage.

Strobe effects and the danger of seizures

• LED light flicker on video can produce a strobe effect, where the lights pulsate at a frequency that is perceived as a rapid series of flashes.
• This strobing effect can be visually uncomfortable for viewers and may even trigger seizures in individuals with photosensitive epilepsy or other related conditions.
• It is crucial to minimize or eliminate strobing effects to ensure the safety and well-being of the audience.

Challenges for professional photographers and videographers

• Flickering can disrupt the intended lighting setup, making it difficult to maintain consistent and accurate color rendition.
• Professionals who rely on slow-motion or high-speed recording techniques may face additional hurdles, as the flickering can become more apparent and pronounced in such scenarios.
• Time-consuming post-processing efforts may be required to correct or mitigate the effects of flickering, potentially delaying project completion and increasing production costs.

Also read: Manufacturing Process of LED Lights & Fixtures?

How To Stop LED Lights From Flickering On Camera?

Synchronizing camera frame rates with LED light frequency:

1. Determine the frequency at which your LED light flicker on video by using a slow-motion camera or a specialized LED flicker detection tool.
2. Adjust the camera’s frame rate to be an exact multiple of a fraction of the LED light’s frequency to achieve synchronization.
3. By aligning the camera’s frame rate with the LED light frequency, you can reduce or eliminate flickering in the captured footage.

Stabilizing voltage supply and reducing fluctuations:

1. Ensure a stable power supply by using high-quality power sources and surge protectors.
2. Consider using voltage regulators or stabilizers to minimize voltage fluctuations caused by irregularities in the power grid or other electrical devices.
3. If using dimming controls, choose compatible ones that provide smooth and consistent dimming without introducing flickering issues.

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Using LED lights with high-frequency PWM

1. Opt for LED lights that utilize high-frequency pulse-width modulation (PWM) for dimming, typically above 1 kHz.
2. High-frequency PWM reduces the likelihood of visible flickering, as it surpasses the sensitivity of most cameras to capture the pulsating effect.
3. When purchasing LED lights, check the specifications or consult with manufacturers to ensure they employ high-frequency PWM dimming technology.

Utilizing dedicated dimming controls and compatible fixtures

1. Use dedicated LED dimmers specifically designed for LED lighting systems to ensure smooth dimming performance.
2. Choose dimming controls that are compatible with your LED lights, considering factors such as voltage compatibility, dimming range, and flicker-free operation.
3. It is advisable to test the compatibility between LED lights and dimming controls before undertaking critical video or photography projects.

Alternative lighting options to avoid flickering issues

1. If LED light flickering persists despite applying the above solutions, consider using alternative lighting options such as incandescent bulbs, fluorescent lights, or tungsten lamps.
2. These traditional lighting sources do not exhibit the same flickering characteristics as LED lights, providing a workaround for situations where flickering is a persistent problem.

You may also like to read our detailed guide about reasons and ways to stop LED lights flickering.

Final Words

In conclusion, the flickering of LED lights in video and camera recordings can often pose challenges for content creators and professionals in visual media. This flicker typically results from a mismatch between the frequency at which the LED lights pulse and the frame rate or shutter speed of the camera. LED lights commonly operate by rapidly turning on and off at frequencies that are generally imperceptible to the human eye but can be captured by the sensitive sensors of modern cameras. When the frequency of the LED light pulses aligns closely with the camera’s capturing speed, it can create a strobing effect in the recorded video, which can be distracting and diminish the quality of the footage.

Addressing this issue effectively requires an understanding of both the lighting equipment and camera settings. Adjusting the shutter speed or changing the frame rate of the camera can often mitigate the flickering effect by either syncing with the frequency of the LED lights or by smoothing out the appearance of the flicker in the final footage. Alternatively, using high-quality LED lights designed specifically for video production, which offer flicker-free performance or have adjustable refresh rates, can resolve these issues without needing to compromise on camera settings. For those in professional settings, investing in specialized lighting equipment that ensures consistent illumination without pulsing can be a worthwhile consideration to maintain high production values. Ultimately, understanding the technical aspects of both LED lighting and camera operations is key to overcoming the challenges of flicker, ensuring that the final visual output is both pleasing and professional.