Using the hand method, three fingers correspond to mils?

Using the hand method, three fingers correspond to mils?

• A. 50 mils
• B. 150 mils
• C. 100 mils
• D. 200 mils

Answer: (C)

Mils measure angular size in the sight picture, and the hand method gives a quick, rough way to estimate that angle using your own hand at arm’s length. When you place three fingers across your line of sight, that span typically subtends about 0.1 radians, which is roughly 100 mils. Put another way, 100 mils corresponds to about 5.7 degrees of angle; at arm’s length, a span of roughly six centimeters across the field of view matches that angle, and three fingers fit that range for most people. So the three-finger span is commonly taken as about 100 mils. If you used a smaller span, you’d be closer to around 50 mils, while a larger spread would approach 150–200 mils, which is why the three-finger estimate best fits the 100 mils mark.

Mils measure angular size in the sight picture, and the hand method gives a quick, rough way to estimate that angle using your own hand at arm’s length. When you place three fingers across your line of sight, that span typically subtends about 0.1 radians, which is roughly 100 mils. Put another way, 100 mils corresponds to about 5.7 degrees of angle; at arm’s length, a span of roughly six centimeters across the field of view matches that angle, and three fingers fit that range for most people.

So the three-finger span is commonly taken as about 100 mils. If you used a smaller span, you’d be closer to around 50 mils, while a larger spread would approach 150–200 mils, which is why the three-finger estimate best fits the 100 mils mark.