# Of 60i, Hockey and High Sticks

Say a slapshot taken by a typical hockey player moves at 80mph (117.33 feet/sec).

Based on what research I could do into filming fast paced things such as hockey, it’s recommended that one shoots in 60i, which captures 60 frames/second, and most network broadcasts do.

Does that means that roughly 2 feet of puck movement is captured per frame? How does a hockey game seem so fluid, then, even in slow motion? Does that mean that video review of something like a goal scored off a high stick might have to be done from images that might not even include the actual deflection, but possibly from those a foot before and a foot after the player’s stick?

This doesn’t seem to jive with my perception of watching games on TV, so am I just under the spell of the magic of television, or am I right in thinking that these numbers don’t add up to reality and that there’s something missing?

It jives with me. Remember, that 2 feet/frame is only for when the puck is moving at its maximum speed. When it hits something, it slows way down, even if it speeds back up a lot as it rebounds. And the person who deflects the puck isn’t going to be moving at 80 mph, so they’re not going to be moving from hands down to hands above shoulders to hands down again in 1/60th of a second.

So yeah, regular speed video, stepped through one frame at a time, will show a slapshot puck as a blurry object moving two feet between frames, while the deflector will take at least 10 or so full frames to lift their stick (even if they’re moving nearly as fast as possible), and likely another 20 or so holding their stick (that’s just 1/3 of a second). The puck will probably be contacting the deflecting stick for a couple full frames.

And of course, on TV, they’ve got slow-motion cameras going for stuff around the net. The original shot, at full speed is 60 frames/sec, but the replay might be shot at many times that.

They use high speed cameras for slow motion replay. For example: http://sportsvideo.org/main/blog/2010/04/21/inertia-unlimited-xmo-settles-into-mid-season-mlb-mode-at-regional-nets/