The refresh rate or frequency is the number of times per second that an image is drawn on an LED screen. The image that forms on the screens is the result of hundreds of continuous refreshments in each of the LEDs in a way that is imperceptible to the human eye. Its unit of measurement in the international system, as it is a frequency, is the Hertz (Hz).
Its main difference with the number of frames per second, is that the refresh rate/frequency includes a number of identical frames that are reprinted on the screen every second, while the second discards the repetitions of the same frame in its measurement.
Some hardware players have frame interpolation or dither technology. These systems generate new frames by making a comparative calculation between two consecutive frames. In this way, they generate a new intermediate image between 2 real frames of the video content These interpolated or dithered frames allow to reproduce contents with more frames per second, offering an improvement in the reproduction and fluidity of contents with accelerated movements.
A high refresh rate tells us the ability of the screen hardware to redraw the contents of the screen several times per second. This allows the emission of moving images to be smoother and clearer, especially when showing fast movements in dark scenes. In addition, a hardware with high frequencies of refreshment will be more suitable for the emission of contents with a greater number of frames per second and to be connected to multiple input players.
In professional uses it is crucial to offer very high refresh rates. This is especially important for screens oriented towards the entertainment and media sector and, which will surely be recorded on video by professional cameras. A refresh rate that is in sync with the camera’s recording frequencies will make the image look perfect and prevent blinking. This is achieved by using content and LED screens with refresh rates that are multiples of the fps format used by the camera.
LED screens are compatible with multiple video standards with different numbers of frames per second (fps). The most usual for content in European PAL video standard is to use 25 or 50 fps. In the American NTSC standard, 30 or 60 fps are usually used. The contents in cinema format are 24 fps. Any of these standards can be reproduced by a LED screen provided that it has the appropriate codecs and the reproductive system is compatible.