Dan Luu

i've been using my iPhone's slow mo video capture to measure input lag. 60hz usually, trying to figure out how to record at 120 or 240hz. is that an OK method? anything i'm missing?

specifically, i make sure i have my keyboard and the player character in view. then i hit the key as sharply as possible, and count the frames between my finger hitting the key and the character moving.

Sounds approx like what @danluu describes in https://danluu.com/keyboard-latency/ … but at 240fps

If you have a really low-latency setup (fast display, OS settings tuned nicely, quick keyboard, etc.) and the game isn't buffering much, you may want a 1000fps camera for this since you should be able to get into the 30ms range (see http://danluu.com/input-lag/  for some examples).