How can it be that films in 1000 fps are slow-motion but when you play a game and the fps varies from lets say 60-250 it doesn’t get “slower” the closer you get to the 250?

Question

Because you would then assume that higher fps = slowmotion / slower image

In: 0

Answer 1

If a video is recorded at 1000 fps, and you play it back at 1000 fps, it won’t be slow-motion.

However, that’s not what happens. The point of recording at such high framerates is that you can then play it back at something like 60 fps, and see a smooth video in which time progresses much more slowly than in reality. For instance, if you played it back at 50 fps, then one second in real recorded time would be stretched over 20 seconds of playback time. This is how you get the slow-motion effect: things that took 1 second in real life now take 20 seconds.

You need the high recording frame rates for the video to look smooth when its played back slowly. For instance, say you recorded at 60 fps and then played the video back at 3 fps. Again, this would mean that 1 second of recorded time would be stretched over 20 seconds of playback time. Only now, every second you play back only contains 3 frames, so it won’t look smooth at all. Instead, it will look like a fast slide show. And you don’t really get the benefit of slow-motion allowing you to see fast movements slowed down, because anything that happened in between those 3 frames is either not captured or smeared out as motion blur in each frame.

When you play a game, the fps is simply how many frames are drawn every second. At 30 fps, the game world is rendered 30 times per second. At 200 fps, the game world is rendered 200 per second. But the rate at which time progresses in the game world isn’t changed. It’s just a matter of how many “glimpses” you get of the game world in each second. There’s no recording and playback. Or, if you prefer, you can think of it as recording the game world and playing it back at the exact same time, with the same frame rates for recording and playback.