title_body: How to visually inspect the magnitude of PID gains? The defaults in Betaflight generally work very well, but I own and fly very different quads ranging from 2" to 6". It may easily be that there is room for little adjustments I can make with the tuning sliders in the Configurator. How can I use graphs and plots generated from blackbox data to determine whether the PID gains on a certain quad are excessive or too low or about okay? How do these scenarios manifest visually in Blackbox Viewer or other visualization tools?
upvoted_answer: This comes with an understanding of how the PID algorithm works and what it actually does. Bardwell videos can be good, but non-quadcopter reference on what a PID controller is will be the best way to visualize this.
  
  Look at the individual P, I, D components, and see how they react to the gyros. A properly damped (critically damped) system is what you're aiming for. I don't remember the math, but you also can't just apply straight math to this, because some of it is by feel (looser = underdamped, tighter = overdamped).
  
  Here's a photo stolen from quora (https://www.quora.com/What-are-over-damped-critically-and-under-damped-systems):