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Lighting with RGB LEDs Answered

Hi all. I am wanting to get into using led lighting for long exposure photos (for the purpose of thermal imaging) and I am looking at RGB LEDs for providing the colour. My question being, should I try finding LEDs that have similar light output in mcd or stick with RGB LEDs? The reason I am asking is when I am looking at specs, the green seems to be 2 to 4 times as bright. Is this an issue? 

Also, the RGB LEDs seem to have a much wider viewing/ lighting angle. 

I am not sure where to go from here. Any help would be appreciated. 

Thank you all very much for the time. 

Professorred

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lemonie
lemonie

8 years ago

If you want to capture "thermal", i.e. infra-red then you should use long-exposure on a digital-camera (silicon picks up IR better than film).
If you just want light then it doesn't matter much, unless you want lighting that isn't visible to human eyes?

L

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professorred
professorred

Reply 8 years ago

Thank you. I am wanting visible light. I was wondering because it sounds to me like when there is a mixture involving the green, there will be too much green. I was wondering if this would be correct (and I should try to match the mcd output) or it there is something to do with optics that negates this (meaning that I should not if I want the green to be equal).

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lemonie
lemonie

Reply 8 years ago

You can get "white" LEDs, they look white. But if you're capturing with an electronic camera they may look different.
I don't know any better.

L

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professorred
professorred

Reply 8 years ago

I am trying to get different colors to show different temperatures. I am just trying to figure out if the RGB LEDs will have too much green. I guess I can always try it and see if it will work.

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lemonie
lemonie

Reply 8 years ago

You should probably use a tungsten-halogen bulb if the temperature range matters. But I don't quite understand why the illuminating-temperature matters.

L

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professorred
professorred

Reply 8 years ago

I was inspired by https://www.instructables.com/id/Build-a-Thermal-Flashlight-Light-Painting-with-T/ and wanted to make it.