Mirror Gain

[Supadog]

Hi,

I've asked someone to make me a parabolic mirror for a robot and they want to know the 'mirror gain' i would like. Does anybody know what 'mirror gain' is?

thanks

[brewnog]

If the mirror is pointing straight back at the light source, the light will be "concentrated" if you will, onto a smaller projected area, but with a greater intensity, directly back in the direction it came. Think of the bright flash you get instantaneously from a lighthouse or fire engine warning light. The gain is just the ratio of the two intensities. (Although, depending on how you want to express the gain, it may be a log of this ratio).