Today we have a topic related to video, we talk about the image frequency, also called frame rate or frames per frame or per second.
A frame or frame is each of the images that form a video. They are expressed with the acronym fps and in hertz (Hz).
The expression is used in the fields of video, cinema or computer graphics. We can make a recording in different frames per second, depending on the type of video, what we are going to record or where it is going to play.
Progressive Vs Interlaced
A moving image can be formed in different ways depending on whether we use the frames in a progressive or interlaced way. What is the difference?
‘In progressive each frame shows all the lines that make up the image. The progressive format is expressed with a p (1080p).
-In interlaced each frame only shows half of the lines of an image, therefore two frames are needed to show the complete image. In static images the quality is fine, but if the images contain a rapid movement they produce lines as if they were blinds. The interlaced format is expressed with an i (1080i).
Like it was before
At the beginning of the cinema there was no base projection speed because, when using cameras with a hand crank, it was impossible to maintain the same speed all the time. It was with the arrival of synchronized sound when 24 frames per second were set as standard speed.
The taumatropo, in wonderturner English, is one of the precursor toys to the cinema. It is a disc with two different images on both sides and a piece of string on each side of the disc, when we turn the discs quickly with the string it produces the illusion that both images are together. In the video you can see it in action.
How it is now
We go with the types of frame rate that exist now, and how and when to use them. To simplify, we will name only the best known that would be 24 fps in cinema, 25 fps in PAL system of European television and 30 fps for the NTSC system of American television.
24 fps
When you want your video to have a cinematic appearance, such as a short film, record at 24fps. It is the most common frame rate, to which our brain is more accustomed, but that does not mean that you cannot use other speeds.
The only drawback of this format is that moving images lose sharpness. If any of the scenes is slow motion and the movement is very fast, keep in mind that the image will not be completely fluid.
There are currently directors who have begun to experiment and record their films above 24 fps, such as Peter Jackson in The Hobbit, which did so at 48 fps.
In fact, it is a matter of debate among the spectators. Those in favor think that it is a way to get even more realism and detail to the image. The detractors, on the other hand, think that recording at a higher frame rate causes the characteristic texture of the cinema to be lost and reminds them of the television look.
25 fps and 30 fps
The 25 fps are used in European television with the PAL system, on LCD screens, computer monitors or projectors.
On the other hand, in American television, having an NTSC system uses 30fps.
And more fps
There are some cameras that also allow recording at 50 fps and 60 fps. It is used in high definition televisions, but at the moment it has not been standardized.
From 60 fps, such as 100 fps or more, they are used to record slow cameras with a sharpness incomparable with slow cameras of 24 fps or 25 fps. The more frames that make up your image, the more fluid and crisp your image and slow motion will be. This can be very useful for recording sports or very fast movements.
