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What is Signal-to-Noise Ratio in Video?

Signal-to-Noise Ratio in Video

Last updated on January 23rd, 2024 at 02:18 am

You may have come across the term signal-to-noise ratio in product brochures or descriptions.

Sometimes it is written in the short form SNR or S/N.

So, what does signal-to-noise ratio mean? What should you know about it?

To put it simply in the context of video it is the ratio of good video (signal) against “useless” video (noise).

When we talk about video noise, we usually refer to underexposed video. It affects the clarity of a video and usually, a grainy video is one that contains much noise.

No video can be totally free of noise, but if the noise proportion is so low that it’s not noticeable to the naked eye, then we say that the video has a good or high signal-to-noise ratio.

How is Signal to Noise Ratio Measured?

Signal to Noise Ratio is measured in decibels (dB).

A ratio of 1:1 signal to noise ratio equals 0 dB.

The higher the signal-to-ratio the higher the perceived video quality

What is a Good Signal-to-Noise Ratio for Video?

Experts agree that a good enough video quality should be in the range of 15.3 dB and 17.2 dB. 

At 48 dB video can be said to be virtually noise-free.

A 4K studio camera like the Panasonic AK-UC3300GJ/UC3300GSJ can go up to 62 dB.

Signal-to-Noise Ratio in Audio

The same signal-to-ratio principle is applied to audio. This would be the ratio of the useful audio signal to the ‘junk’ signal.

The signal-to-noise ratio in audio can be increased by the use of noise reduction systems.

How to Minimize Video Noise

As mentioned earlier, video noise is usually the result of poor lighting. Good lighting in most instances will minimize video noise.

Use a high-resolution camera. 4K video cameras will do a better job than 1080p Full HD cameras.

You could also use a high-resolution camera with a large sensor size. The larger the sensor size the higher the signal-to-noise ratio that results.

Sometimes you realize your video has a high level of noise only after shooting the video.

In this instance, you would have to use a good video editor to minimize noise or denoise your footage. But there are cons to consider as the video below explains.

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