What would happen if you combined a TIR and reflector?

[MacTech]

just out of curiosity, what would happen if you were to combine a reflector and TIR optic, lets say in a SF KL-1 or KL-4?

I'd imagine there is some light lost to the non-reflective heatsink and absorbed /reflected back to the emitter with a standard TIR optic, i'd imagine combining a reflector *and* optic would allow almost all the light lost to the heatsink and such to be reflected back out....

in theory, a reflector/optic combo should allow both a long throwing beam and a decent amount of spill

anyone tried this?

 

[dyyys1]

I've never had a TIR light before. Does it really lose enough light out the back to make a reflector worthwhile? I thought a TIR caught close to 100% of the light.

 

[Alteran]

I thought it was closer to 90%.:thinking:

 

[nerdgineer]

I tried something like that when I added different reflectors into an LED light which had a focusing lens and created a spot beam. Basically, I got the same focused spot plus a wide donut ring around it.

The reason is simple. Light going forward from the LED was focused into a spot by the lens as before. The light which was going sideways - that was lost before - is not also pushed forward by the reflector. However, the lens is designed to focus a point light source into a collimated beam. The reflected photons are moving forward more or less in parallel (like a point source far, far back from the lens) so the same lens focuses them into a different pattern and not into the original spot or a contiguous spill beam. In my case, that new pattern was a wide donut with a pronounced dark band between the spot and the ring. Uglier than the spot alone.

It might be possible to custom design come combination of reflector and collimator, but I think you'd have a hard time not getting a donut because of the 2 distinct ways light would get from the led out the front.

Anyway, after fiddling for a while, I removed the reflectors and kept it just as a spot.