I have seen posts here saying to use red and not clear LEDs behind red tail light lens to get more visible light. If this is true why are OEM filament bulbs clear and not red tinted? TIA
Red vs clear LEDs question
- Thread starter ffhdriver
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Because a red LED emits ONLY red light. A standard bulb with clear glass emits light of every color.
Case in point: if you have a 1000 lumen red LED and put it behind a red lens, you will still get almost all 1000 lumens passing through. If you place a 1000 lumen white LED behind that same red lines, you will get significantly fewer lumens because they are being filter.
Case in point: if you have a 1000 lumen red LED and put it behind a red lens, you will still get almost all 1000 lumens passing through. If you place a 1000 lumen white LED behind that same red lines, you will get significantly fewer lumens because they are being filter.
White LED's put out very little red light.
The Kenworth I drive at work has the clear lens LED lights ( usually called ice lights) the LEDs themselves inside are also clear, but when you turn them on or put the brakes on, they glow red, and a very intense red. They seem to be brighter than the red lens LED lights on the other trucks in the fleet.
Different white light sources put out different amounts of light in different parts of the visible spectrum. This first spectrograph is of a white LED. Notice that on the right hand side in the red light part of the spectrum (~675nm), almost no light is being emitted.
This second spectrograph is of a normal incandescent lamp. Notice that most of the light being emitted is in the red part of the spectrum. (Disregard that spike in the infrared, the spectrometer used to measure this lamp gets flaky that far out in the spectrum)
Keep in mind that both of these lamps will appear to the eye to be white, but put out light in very different parts of the spectrum. Since much of the light emitted by an incandescent lamp is in the red part of the spectrum, a red tail light lens will not filter out very much of the light emitted by that lamp. That same tail light lens will filter out almost ALL of the light emitted by the white LED.
This second spectrograph is of a normal incandescent lamp. Notice that most of the light being emitted is in the red part of the spectrum. (Disregard that spike in the infrared, the spectrometer used to measure this lamp gets flaky that far out in the spectrum)
Keep in mind that both of these lamps will appear to the eye to be white, but put out light in very different parts of the spectrum. Since much of the light emitted by an incandescent lamp is in the red part of the spectrum, a red tail light lens will not filter out very much of the light emitted by that lamp. That same tail light lens will filter out almost ALL of the light emitted by the white LED.
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