Red Dot Range Estimating People with the Naked Eye
This works for my eyes. Yours might be slightly different.
50 yds - Face T box features (my Max pistol range)
200 yds - featureless no face ( Center Mass point of aim, point of impact with 50 yd zero)
300 yds - head looks like pin dot on top of body. Red Dot on face to drop bullets into Center Mass.
400 yds - space between legs still visible. No distinguishable head. Old Point is on top where head would be.
500 yds - people look like a little thin lines to me. No distinguishable features. Hold Point is cut the line in half and hold that distance over.e
Link to original video from Shrek. this video confirms that the system works. It does however need to be calibrated to your specific eyesight. That means adjusting the distance. I completely dropped use of arms, because I could not see them. Most likely due to heavy jackets this time of year. Fun exercise to experiment with on today's event you can't be having fun at the gun range.