Judder is a motion problem on a TV that makes moving objects or camera movements appear uneven, jerky, or slightly choppy rather than smooth. It is especially noticeable during slow camera pans, such as when the camera moves steadily across a landscape or follows a person or object.
Judder usually occurs when the frame rate of the video does not match the TV’s refresh rate. For example, most movies are filmed at 24 frames per second (24 fps), while TVs commonly operate at 60 Hz or higher. Since these rates do not divide evenly, the TV has to display some frames for longer than others. This creates an uneven motion pattern, causing the image to appear as if it is moving in small jumps rather than smoothly.
What is judder on a TV?
Now let’s take a closer look at judder and what causes it. Judder is a motion issue that makes moving objects or camera movements appear uneven, jerky, or slightly choppy rather than smooth. It is particularly noticeable during slow camera pans and in movie scenes with steady movement.
Judder commonly occurs when the frame rate of the content does not match the TV’s refresh rate. For example, most movies are recorded at 24 frames per second (24 fps), while many TVs use a 60 Hz refresh rate. Because 60 is not evenly divisible by 24, the TV cannot display each movie frame for exactly the same amount of time.
To solve this, TVs commonly use a technique called 3:2 pulldown. The TV repeats some frames three times and others two times to convert the 24 fps movie into a 60 Hz signal. This creates an uneven frame pattern: some frames remain on the screen slightly longer than others.
The difference is very small and usually not noticeable in most scenes. However, during slow camera movements or when objects move steadily across the screen, this uneven frame timing can become visible. The result is a characteristic stuttering or slightly jerky appearance known as judder.
How to get rid of judder?
TV manufacturers use several technologies to reduce or eliminate image judder. One of the simplest and most effective solutions is 24p playback, which allows compatible TVs to display cinematic content at its original frame rate of 24 frames per second, without converting it to 60 Hz or 120 Hz. In simple terms, the TV and its T-CON board are designed to support the direct display of 24 frames per second, preserving the original frame timing of the movie.
Many modern TVs also support motion interpolation. In this case, the TV analyzes consecutive frames and generates additional intermediate frames to make movement appear smoother. Depending on the manufacturer, this feature may be called Motion Smoothing, TruMotion, MotionFlow, Auto Motion Plus, or something similar. The processing is performed by the TV’s image processor and is specifically designed to compensate for uneven motion and improve fluidity.
However, motion interpolation has its drawbacks. It can create the well-known “soap opera effect,” making movies look unnaturally smooth and different from the way they were originally filmed. In some situations, it can also produce visual artifacts around moving objects.
For this reason, many viewers prefer to disable or minimize motion interpolation when watching movies and instead use the TV’s native 24p support. This preserves the original cinematic appearance while avoiding unnecessary image processing.
It is also worth noting that judder has become much less noticeable on modern TVs. Advances in image-processing algorithms and more powerful processors have significantly improved the way televisions handle frame-rate conversion and motion. While judder was a more noticeable problem on older TVs, modern models generally handle it very well. Today, pronounced judder is more likely to be found on budget TVs with less powerful or outdated image processors.
