# Confusions regarding frame rate?

We know that when many image are shown in succession they create illusion of video

1. But what is the minimum rate of frame/images so that still images appear as video?
2. In this case, images/frames are moving horizontally or vertically?

In this case, images/frames are moving horizontally or vertically?

Neither. They just appear; usually, they stand still for as long as a frame is displayed.

But what is the minimum rate of frame/images so that still images appear as video?

That depends on a lot of factors like brightness, amount of motion in the material, and mental state of the observer.

Typically, upwards of roughly 20 frames a second, things are perceived as fluid motion, but there seems to be some benefits to going higher in frame rate, especially in high-movement scenes.

Traditionally, cinema and TV used to be 24 or 25 frames a second, but this number has changed in recent years, with digital TV producing whatever frame rate the video codec used does.

The vision centre of the brain retains an image for $$\frac{1}{15}^{th}$$ of a second and any image added in that time frame gives a sense of continuity. 24 FPS is mostly used in movies and TV.

Also, the images do not move horizontally or vertically in spatial domain to create a sense of motion.