Flashlight Output Through Filters

[beezaur]

Hi Guys,

Has anyone examined how much light gets through filters put on their flashlights?

I know when you put a red filter on a white LED, the output is greatly diminished. White LEDs tend not to produce much red light. But when you put a blue filter on an LED, you get a lot of light.

The opposite is true of incans. Red filters on incans pass a lot of light, but not much blue gets through.

Has anyone measured this in any way? Have there been spectrographs made?

Scott

 

[cratz2]

I don't have any way to take any such measurements. I realize the differences between the different color filters being used with LED or incand, but I have often wondered how much of a difference using cheap plastic makes vs camera lens quality glass? I've never taken apart any colored lenses, but two of my modded Mag lights lights have salvaged camera lenses in them.

 

[kanarie]

Has anyone examined how much light gets through filters put on their flashlights?

I know when you put a red filter on a white LED, the output is greatly diminished. White LEDs tend not to produce much red light. But when you put a blue filter on an LED, you get a lot of light.

The opposite is true of incans. Red filters on incans pass a lot of light, but not much blue gets through.

Has anyone measured this in any way? Have there been spectrographs made?

try to get hold of a example booklet with gel filters (Lee) it has all the diagrams you will ever need for every filter
you will see than throughput can vary from 10 percent to 90 percent within one color