John McPhee, former Delta Force sniper, offers some good tips on how to quickly judge distance by recognizing different body parts with the naked eye. For example, the difference between 100 and 200 meters is the recognition of the face. It is always interesting to see how people can perfect their craft based on their lessons learned downrange. This would be a great video if you are thinking about becoming a sniper or enjoy competitive shooting.
Image courtesy of Youtube
Video courtesy of Trigger Time TV and SOB Tactical