LED for infra Red signal

[Brady]

Any advice on budget level LED fixture to work on a dance show. I am looking at mainly using deeper colour range so not to bothered about the fact that LEDs struggle with warmer colours. What is my major consideration is that I am using Infared cameras to pick up the movement of the dancers and need something that will not interfere with this if possible. I also have a small budget and I'm looking at purchasing 4-6.

 

Any help would be great

[Jivemaster]

You will likely find that LED emitters are roughly spectral with some serious peaks, but the cameras -called infra red- will actually have a broad spectrum response from blue well into the IR region. You may need to put filters over the lens to pass only IR and even that will be a steep but sloping cut. Wratten 87C to the Wratten 89 series. http://medicalphotography.com.au/Article_03/02c.html refers to all the technique.

 

There is no knowing whether your LED disco lights will emit any or sufficient IR for your needs, and without tests there is no knowing how much visible light the IR filters will pass. There are three sorts of IR emitters, 1K tungsten with a glass wratten 87 filter, LED with some visible red light pass, and LED IR with NO visible light pass. For security work the visible light passed acts as an indicator/deterrent of lights and cameras, for your work you may want to use a tighter cut light source with NO visible light shown but then you need night vision scopes to see whether they are on or not!

 

If you get gelatin filters then perhaps you can cut them to suit your camera lenses but genuine gelatin filters are destroyed by a fingerprint so wear cotton gloves or handle them inside the tissue paper fold they (should) come in (or both! they are fragile).

 

Also be aware that not all clothes are IR opaque! Be careful what you expose/record/distribute.

[DrummerJonny]

you need night vision scopes to see whether they are on or not!

 

Or a camera phone...

 

This also works for checking the batteries in remotes.