Where can I found example video in 120fps and up?
Most slo mo iPhone videos are 120-240fps. Higher production quality videos that have slowed down video usually shoot at 60fps and cut it in half to 30fps. This is due to many high ends cameras not shooting high speed and if they do it is usually at lower resolutions. That is unless they have a camera dedicated for high speed like a phantom flex. The second part about making a slow motion video. You don't really make it. You shoot something that is going to be cinematic slowed down or adds emotion to it when slowed. Then simply cut the video to 50% or less depending on the frame rate. General rule of them is don't go under 30fps as it gets very choppy.