Its important to understand a few simple terms and concepts with regards to digital video, and resolution and frame rates are both simple and essential.
Resolution
The resolution of a video refers to the number of pixels that make up each single image or frame of the video. The higher the number of pixels, the higher the quality of the image.
A pixel is essentially a tiny "coloured dot" that, when combined with thousands of other pixels, form an image.
The resolution of a video is given as the number of pixels of the width and height of each image. For example, a full HD video image is made up of 2,073,600 pixels, but is represented like this:
HD Video resolution: 1920 x 1080 (width x height)
Frame Rate
Frame rate refers to the number of sequential frames, individual images, that are displayed to produce the illusion of a moving image.
In cinema, a single second of movement is shown in 24 frames. Our brains interpret this rapid succession of images as movement, and thus creating a successful illusion.
The speed and frequency of this display is referred to as a Frame Rate and is measured in Frames Per Second (FPS). So taking the above example of a cinema projector, it displays video at a rate of 24 fps.
Example: A DVPAL video has a resolution of 720 x 576 and a frame rate of 25fps.
Both resolutions and frame rates are extremely variable in the world of digital video and are important terms to know and understand.
What about Refresh Rates?
Refresh Rates are a slightly more complicated concept, relating to the speed at which your screen or projector "draws" an image. Refresh rates are becoming a more common term with HD video recorders and are measured in Hz (hertz - cycles per second).
Common HD camera refresh rates are 50hz and 60 hz - the former more common in PAL regions and the latter in NTSC regions (more on PAL and NTSC here). More info on refresh rates here.
How can I check the frame rate and resolution of files on my computer? In Windows: Right click on your video file and select “Properties”. Select the “Summary” tab and click on “Advanced”. Here you will see the video’s frame rate and resolution (Image width and height). In OSX: Click once on your video file, then press Command (apple) + I. This will bring up an information box with the video fille details. In Ubuntu: Right click your video file and select “Properties”. Click on the “Audio/Video” tab for video information.
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