Gold reflectors

I'm curious as to whether there would be any advantage to using Gold plated reflectors over chrome or Rhodium plated ones.

I have noticed that when I reflect a cold LED light off of polished brass and onto a white surface the beam does warm up quite a bit.

Now that you mention it I think I have noticed that effect too. That would be an interesting alternative to a beam filter. As I understand it silver takes the highest polish of any metal but it tarnishes easily so other white metals are commonly used. I think the white metals are preferred because they're reflecting the full spectrum and therefore more efficient but efficiency isn't always the top concern.

indeed, interesting. for those who'll take the hit in efficiency with those warm white LEDs, a gold plated or similar metal'd reflector would do fine too..
hmm. you may be on to something here.

but.. in my opinion. gold reflectors would look rather strange?

I think it would look blingin'! or Dope! or sick! which ever floats your boat..... haha but a gold reflector would definitely be cool/interesting to see. nice job! thinking outside the box! gotta love it!

The spillbeam would be warmer than the hotspot, but it would indeed be bling..

I understand that gold can be very efficient in reflection transmission. With a good gold reflector that is reflecting most of the light, I do not believe you would see a drastic tint change. It seems to reason that the only way to change the tint noticeably would be to filter out (absorb in this case) some of the light. :shrug:

The way I've heard it is the interesting optical quality of silver is its high degree of polish and the interesting optical property of gold is that it can be hammered into sheets thin enough to see through. IIRC from my childhood field trip NASA uses a real gold film on the visor of their space helmets because they can protect against harsh sunlight but still allow their astronauts to see out.

I do know that the colors we see are the result of different colors of light being reflected or absorbed by different materials. For instance white reflects all colors of light so it's good to wear on a hot day because it will reflect solar energy. Black will absorb all colors of light so if you wear black on a hot day you'll heat up pretty quick.

If you reflect light off a shiny surface of a given color the reflected light is also of that color. If you have a shiny penny and a shiny dime you can do a side by side comparison. Aim you light away from a white surface but reflect the light onto that surface with the coin. My blue mirrored sunglasses reflect blue light. I would guess that StarHalo is correct that the spill would be effected to a greater degree than the hot spot but with the right reflector or optic may do a lot to even it out. Even if it didn't it would be a neat effect that might even have some practical use.

I recieved some good input here, now I think I'll take this one set further and do some testing.

The spillbeam would be warmer than the hotspot, but it would indeed be bling..

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The reverse is true. The hotspot (the part reflected from the gold reflector) would be warmer than the spill (the part that goes straight out the flashlight). Warm hotspot with cool spill is actually a pretty nice effect -- comparable to cool white sky, with a warm white sun (providing direct illumination).

One of these days at work I may try sputtering some gold over one of my small plastic reflectors when nobody is looking to try this out...

hmmm, i wonder if i can have them custom made by local jewellers? :sleepy:

betta tell them what OP means in case they made it smo... :laughing:

Sounds very cool.

Looking forward to your test results and pics.

Sgt. LED said:

Looking forward to your test results and pics.

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+1

What about (very) highly polished brass?

Here's my 2 cents.

A proper reflector by definition should not affect the color of the beam it reflects. A proper reflector reflects 100% of the light that is incident upon it, so if a gold reflector is as efficient at reflecting light as a silver/aluminum/rhodium/etc. reflector it should not tint the beam enough to perceive a difference.


That being said a gold reflector would look damn cool.

65535 said:

Here's my 2 cents.

A proper reflector by definition should not affect the color of the beam it reflects. A proper reflector reflects 100% of the light that is incident upon it, so if a gold reflector is as efficient at reflecting light as a silver/aluminum/rhodium/etc. reflector it should not tint the beam enough to perceive a difference.

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But gold doesn't reflect 100% of the light incident upon it; it reflects the yellow wavelengths better than other visible wavelengths. The best reflector should be a substance that is colorless, meaning that it reflects all visible wavelengths equally, like aluminum, silver, and rhodium.

LukeA said:

But gold doesn't reflect 100% of the light incident upon it; it reflects the yellow wavelengths better than other visible wavelengths. The best reflector should be a substance that is colorless, meaning that it reflects all visible wavelengths equally, like aluminum, silver, and rhodium.

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I don't care if it doesn't reflect 100% of light, I want to see it done, if just for the sake of fun.

I'm waiting now to hear back about having a McRxx reflector gold plated.

Morelite said:

I'm waiting now to hear back about having a McRxx reflector gold plated.

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Please post photos here if and when you get it.

If it works I have 6 to send! :thumbsup:

I saw a demonstration from a lighting manufacturer about a year ago that used copper and gold colored reflectors to achieve different color temperatures for their HID fixtures. I guess supermarkets know much more than we do about how color temperature makes their products (mainly vegetables and fruits) sell.

I posted about it, but I don't think anyone noticed.