casting an optic.

I plugged an IMS reflector with a luxeon, sealed between them with silicone, and filled the reflector with clear polyester. Now the die looks about four times smaller in area.

What do you think; relative to an empty IMS, will it
1: be 4 times as bright (lux)
2: be 2 times as bright (lux)
3: be less bright (lux)
3: emit more lumen
4: emit less lumen
5: be out of focus

If I ever manage to get the optic and led divorced from the reflector, will it become
A: brighter
B: darker
than before?

it will emit less lumens, and be less bright (lux)

Not sure about the second part. if you remove the led from the reflector, then you get no light (darker) i guess?

The polyester in the reflector would most definately reduce the amount of lumens produced, however, unless you turn it on, Im not sure if you would be able to accurately determine what would happen. My guess would be that it will either be completely out of focus, or, if your extremely lucky, it will have a focused hotspot.

Its really hard to say what will happen without actually turning it on.... we dont know anything about it, the characteristics of the polyester, the reflector, the luxeon. Its all speculation. If you didnt have the polyester, it would definately be brighter, without the reflector it would be just a candle looking thing.

why dont you turn it on and find out?

It is still not completely hardened. I want to wait a bit to stabilise it.

The polyester is definately not high optical grade; the yellow tint is visible. There seem to be some pico-bubbles along the reflector surface, and a couple of mini-bubbles on the top surface.

I believe the IMS is made specifically for luxeons, and a normal high dome seems to be perfectly focused when an empty IMS is seated on it. I think it's parabolic. It's 20mm diameter by 17mm tall.

I'm gessing your optic will be dimmer than the reflector. The contact between the reflector surface and the resin will mess up any optical properties the optic you cast may have (anything touching the surface of an optic messes up the internal refraction).

If you separate the optic and the reflector, the beam will be brighter, but still not good (not clear resin, bubbles, etc.). In addition, you may have a slight shift in dimension (and thus, focus) from using a mold that's already exactly formed for focus to make your optic.

Try casting a rubber mold of the reflector first and using that to form your new optic. That'll also help you release the optic once it's cured.

good info and idea.

so how to I calculate the shift in focus?

BTW it's a good bit dimmer and obviously defocused.

But do you think it is possible to get a tighter focus than with a reflector since the dome is "gone"?

AilSnail said:

so how to I calculate the shift in focus?
...
But do you think it is possible to get a tighter focus than with a reflector since the dome is "gone"?

Click to expand...

That's beyond my technical knowledge, sorry.

Ok, maybe someone else can chime in; will I have to move the led further into the reflector, or the other way?

I did manage to break free the led, and afterwards the optic from the reflector, but the optic got destroyed. But it had a very nice surface where it had been contacting the reflector, I didn't see those microbubbles I was talking about: might have been a hallucination.

I do have some liquid that is supposed to make polyester not stick, but it is so thickly floating that I suspect the surface would become uneven.

What can be used to make a plug from the reflector, and then a mold from the plug? Newbie used wax as a mold, but that can't be used for both the mold and the plug I think.
What sort of rubber were you talking about?