Thunderchicken
Member
I happened across this little distance-estimating trick. I am sure it isn’t news to many on the High Road but thought others might enjoy it. Not sure if this is the wrong place for it, but I am sure someone will move it if not.
https://lifehacker.com/how-to-estimate-distance-using-just-your-thumb-1849365952
For those that don’t want to follow a random link, the idea is simple. Extend your arm, thumb raised, look through one eye and align the left edge of your thumb with the item whose distance is to be estimated. Now close the open and open the closed eye and see how much the left edge of your thumb moved. (This requires you know something about the size of the thing you’re ranging). The distance is 10 times your estimate. Be sure to use the same edge of the thumb in each case!
Works through the miracle of similar triangles and the fact most people’s interpupillary distance is about one tenth the distance from their eye to their thumb. (Note, I haven’t verified this). This is probably not the kind of thing a professional sniper uses but might be handy sometime.
https://lifehacker.com/how-to-estimate-distance-using-just-your-thumb-1849365952
For those that don’t want to follow a random link, the idea is simple. Extend your arm, thumb raised, look through one eye and align the left edge of your thumb with the item whose distance is to be estimated. Now close the open and open the closed eye and see how much the left edge of your thumb moved. (This requires you know something about the size of the thing you’re ranging). The distance is 10 times your estimate. Be sure to use the same edge of the thumb in each case!
Works through the miracle of similar triangles and the fact most people’s interpupillary distance is about one tenth the distance from their eye to their thumb. (Note, I haven’t verified this). This is probably not the kind of thing a professional sniper uses but might be handy sometime.
