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SvennoJ on 19 February 2016
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fleischr said:
SvennoJ said:
I can even see a difference in 480p mode, aka both sides running @30 fps. Another flawed comparison, always exaggerating the 30 fps side. The 2 sides should run in synch at 30 fps.
Actually I see less of a difference in 60 fps mode. Which is odd as I can usually tell when a game is 60fps on tv.

I don't think that's odd at all. The closer in you are to a screen, and the higher that display refresh rate, the more forgiving you can be of lower FPS.

60 fps can always sync properly to 30 fps and will look smooth to the naked eye. The frame times are so small that you get proper frame-to-frame turnover to your eyes regardless whether your not your eye truly sees all frames (it doesn't) However something at 50 fps will likely have uneven frametimes here and there - making stuff look weird.

30 fps conceivably should be smooth as 60 fps, but that assumes your eyes will process the frames in perfect progression/turnover and that frame times are even - neither of which are both the case 100% of the time.

When you sit further away, the image has to travel further, you process the image later and you do feel the difference in how responsive the game feels. With higher FPS, your eyes are more likely to see the frame in sync with gameplay.

I think you've got that backwards and i hope you don't mean travel further as in the time for the image to reach your eyes :) That would be 0.01 micro seconds for 12 feet. It will be a while before we can render 75 million fps for that to become relevant!

What does make a difference is the speed at which objects travel through your visual field. In a small you tube window on a 15.4" laptop the difference is far less obvious than on a big tv. The steps objects take through your visual field are smaller, thus less noticeable that the bits in between are skipped.

In real life your eyes only have a very small sharp fov, 1.2 degrees. You're always scanning the scene and track objects with your eyes, the rods and cones collect the light, detect the edges and pass along that info to your brain. With video running at 30 fps, objects step through the screen which doesn't play nice with your eyes tracking the object. Your eyes don't step along to collect the light, they move smoothly. The higher the fps, the smaller the steps, the better your eyes can focus on and follow moving objects. The faster the object moves, the bigger the screen, the higher the fps needed to be able to still see that object in focus while following it with your eyes. Hence sometimes 240fps can still look better than 120fps.

Eye sight is pretty complicated with elements all working at different speeds. For example move your phone in front of you in the dark and it seems that the lighted screen becomes detached and lags behind. And then you have some situations where less frames per 'brain update' is actually better if those 60 fps only manage to smear things together. You see a big blur close to you when you look out the window in a moving car and at some distance your eyes can track the moving ground and it's in full focus. That distance is not fixed nor a smooth transition. At some distances you can catch glimpses of detail while mostly seeing a blurry image.

Anyway that's the easiest way to spot the difference, rotate the view or pan/scroll and it's obvious.