The Telemeter is a function that measures the approximate distance from the point of measurement to an event such as a firework or bolt of lightning/thunder. It uses the difference between the speed of sound and the speed of light to estimate the distance to an event that generates both light and sound simultaneously.

1. Start the chronograph when you see the light from the firework.
2. Stop the chronograph when you hear the sound of the firework.
3. The value at which the second hand points approximates the distance between your position and firework. As shown in the illustration, the distance to the firework is approximately 1 km.