April 28, 2004

Range Estimation Practice

I've started practicing range estimation.

Here's a problem for you. Look outside your window. There's a car passing by. How far away is it?

I started thinking about this when looking into bullet drop tables. Let's say you sight in your rifle to hit point-of-aim at 150 yards. If you need to hit a target much closer, say 40 yards, how low do you need to hold to hit where you want?

The same problem crops up when playing golf. Of course, with me playing a round every 3 years or so, it's a moot point, but knowing how far you are from the pin helps you select the right club and swing speed.

Football players probably get used to judging distances (at least within 100 yards) and get a lot of help from those hash marks on the field. But you don't get that sort of thing in real life.

Way back when I remember reading a book that gave several "rules of thumb"*. You'd hold out your hand at arm's length, and if a man appeared to be as tall as the length of your thumb, he was x yards away. If his height fit between the tip of your thumb and the first joint, he was y yards away. I wonder if Amazon's new search feature will find that long lost book for me again.

*Maybe this is the true origin of the phrase "rule of thumb"--rather than the allusion to wife-beating that everyone always cites?

Posted by jameshom at April 28, 2004 04:49 PM | TrackBack
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