What is visually even brightness spacing?
Your eyes respond to light in a logarithmic way. That means that a significant perceived increase in brightness requires a doubling in the amount of light. Photographers refer to this change as one f-stop. As an example, to increase the brightness 4 full shades of brightness requires 16 times the amount of light. The brightness levels on your light are spaced to provide small, visually even changes in brightness. How does this affect battery runtimes? As a rough approximation, every two levels brighter will halve the battery life and every two levels dimmer will double the battery life. You can maximize battery life by using the minimum brightness level compatible with the task you are performing. The lowest brightness setting will help preserve your night vision adaptation without using a red filter.
