Collimators?

[Xcandescent]

So the term "collimator" comes up frequently with regards to the Luxeon Star -- obviously, because they sell units with them.

So ... um ... what exactly are they?

Do a search on "collimator" in your average search engine, and you'll likely come up with lots of links to telescope calibration and spectrographic measurement. As you might imagine, this is not helpful when trying to deduce why one would apply such a thing to an LED.

As far as I can tell from reading a few threads, they're just pieces of hard, transparent material that somehow spread the light output from an LED without noticeably reducing its brightness. (Right? Wrong? Help!)

If that's true, then I would certainly be interested in locating collimators for the 5mm Nichia white LEDs, as they might be very helpful in my current project. If not, well I'd still like to know how LED collimators work anyway, what materials are used, what goes into their design, etc.

-XCN-

 

[Xcandescent]

Thanks for the replies. Now that I know what a collimator does, it's fairly obvious it's not what I'm looking for.

Basically, I need a way to spread the light out from a Nichia 5mm without affecting the brightness of the light output -- or at least minimally affecting it. There have been suggestions in the past like scratching up the dome or buying a Nichia with a non-clear assembly (i.e. the NSPW515BS), but since the brightness of an NSPW500BS is just enough to light the screen of a GBA (and non-LED solutions suck too much power) I'm not willing to go dimmer than that. And no, I'm not touching the LS for this; I don't want small children going blind.

-XCN-

 

[Kill-O-Zap]

Xcandescent,

If I'm not mistaken there are wider Nichia 5mm's than the 500BS's, I think the 500 is about in the middle of the range, there are wider and narrower ones. I think they go pretty wide, dunno, maybe 50 degrees or more? If you want to cover a larger surface, there's no getting around the fact that it will be dimmer, whatever route you go, so you might need to use two to four LED's instead of one. More LED's also tends to smooth out the beam.

--Sal

 

[bucken]

Xcandescent,
Sounds like you need the "Afterburner" from TritonLabs.com. They are truly Awesome, if installed properly. I had mine installed by Greg at ImportHQ, and he really does outstanding work.

(Edit) Another option that I did initially was to perform a double LED mod to the LS lightshield. This also works great, and seemed to be OK on power usage. Also use a narrow strip of WriteRite across the black area at the top of the screen. This will help greatly to eliminate the glare from the LED's.

-bucken-

(For those not familiar with GBA's, or Game Boy Advance... The Afterburner is the name of an internal LED screen light product which does an excellent job of lighting up the entire GBA screen from the inside. Getting decent light to the screen after sundown has always been a big problem with GBA's... until the Afterburner.)

 

[woodbender]

Does anyone know if there are different replacement collimators for the ls? I would like to get a couple with tighter spots on them. I want to be able to pop them out and change them for my particular needs. I just started a triple ls maglite conversion today and I would like at least one to project a tighter beam. Any help is appreciated.

 

[Xcandescent]

Originally posted by bucken:
Xcandescent,
Sounds like you need the "Afterburner" from TritonLabs.com. They are truly Awesome, if installed properly. I had mine installed by Greg at ImportHQ, and he really does outstanding work.

(Edit) Another option that I did initially was to perform a double LED mod to the LS lightshield. This also works great, and seemed to be OK on power usage. Also use a narrow strip of WriteRite across the black area at the top of the screen. This will help greatly to eliminate the glare from the LED's.

<font size="2" face="Verdana, Arial">I know about the Afterburner, and most of the existing external light shields and mods out there. IMHO, the Afterburner is probably going to be the best solution as far as screen coverage goes, but there's enough of a washout effect and issues with installation that I'd still like to try to make a good external solution.

I haven't had problems playing my GBA in the dark, but that's only because I imported an Arm Light Advance -- which is probably the best external solution right now once you balance out weight, battery life, and screen coverage -- and even then, the coverage is a bit spotty in the center, and the unit is HUGE. (Haven't evaluated the US Arm Light Advance yet -- surprised it made it over here at all.) Gamester's Flood Light is the champ in the brightness/screen coverage category, but it sucks batteries, and the additional weight of 3 AA's kills my wrists.

I've heard good things about the Joytech Illuminator Pro, but I haven't been able to order one (AFAIK they're only available from one source in the UK).

I'm pretty familiar with the LS mods; I keep in touch with the guy who runs GBAlight.com, and I did a 2-LED mod on a Glowguard which is still posted there. Too bad I didn't know about REAL Nichia LEDs at the time, and used Radio Shack rejects instead.

Of course, that's completely ignoring all the issues with powering the LEDs correctly (which got me into this mess in the first place ...)

I've got a pipe dream that, one day, I'll be able to make a GBA external light that Doesn't Suck. I've got all the necessary features spec'ed out -- but designing and getting a light shield made is not quite the same as making circuit boards.

I should probably be a lot more realistic ... but then if I had been, I would never have gotten to the point where I now have a circuit to properly power the thing.

-XCN-

 

[Slick]

A collimator GATHERS light and is like a lens that the LED kind of protrudes into. The collimator basically gathers and redirects (difuse) light captured from the LED into a usable "beam".

Try playing with acrylica marbles for your nichia's or even a Luxeon collimator works well for this. I've tried it with good results.

 

[Xcandescent]

Originally posted by Kill-O-Zap:
If I'm not mistaken there are wider Nichia 5mm's than the 500BS's, I think the 500 is about in the middle of the range, there are wider and narrower ones. I think they go pretty wide, dunno, maybe 50 degrees or more? If you want to cover a larger surface, there's no getting around the fact that it will be dimmer, whatever route you go, so you might need to use two to four LED's instead of one. More LED's also tends to smooth out the beam.

<font size="2" face="Verdana, Arial">Hmm. I may have to bite the bullet and try to wheedle some wider samples out of Nichia, then. As it is now, I'm planning on using at least 2 LEDs.

-XCN-

 

[Kill-O-Zap]

It's a lens, that's all it is. The LS collimator is pretty oddly shaped as a lens goes, it's more or less of a truncated cone. Looking at it when mounted on the complete LS/O you'd never think it's anything but a lens. Once you pop it out, you say "what the heck is that!". But basically, it's still just a lens.

The reason the LS has an optics option is that unlike the 5mm LED's, LS itself is almost totally unfocused; it spreads light over nearly a whole hemisphere. To get a focused beam like in a flashlight, you could use a reflector, or a collimator, which is more compact and does a much nicer job.

I don't know how useful that would be with a 5mm Nichia. The Nichia's come in different pre-focused beam widths, you can get them pretty narrow if that's what you need.