Explain to me LED optic's, reflector's etc,,,,,,,

Explain to me LED optic\'s, reflector\'s etc,,,,,,,

I was asking on my LSH-P thread about the difference's in optic's Vs reflector's, the advantage and dis-advantage of each kind. I got 3 people PM me offering me reflector LUX III mod's for my ARC, and if i buy another I would give it thought.(to me the light is damn bright anyway, but i know anything can be improved) I know the bigger and or longer the reflector the better the throw or so I read, but what are the beam difference's between these two style's. VDG

Re: Explain to me LED optic\'s, reflector\'s etc,,,,

A reflector is superior for most purposes, because it allows you to have both a tight hotspot and a broad sidespill. But unlike a reflector, a properly designed optic can collect nearly all of the LED's output and project it into a narrow beam. This is what the Inova X0, T1, etc. do.

Re: Explain to me LED optic\'s, reflector\'s etc,,,,

Correction: the optic can collect nearly all of the LED's output in a smaller package and project it forward - you get a good hotspot, but almost no spill.

You can get a reflector that does the same thing, but it'll be far larger than the optic will be, and it'll provide as much throw... but there'll be a hotspot that will be accompanied by a fairly bright corona. While the hotspot is not quite as intense as that produced by an optic, you'll get a wider area illuminated in the process.

Re: Explain to me LED optic\'s, reflector\'s etc,,,,

IMO.....

Reflectors are better for a balanced beam: flood AND throw. Reflectors IMO also provide better beam quality, and top notch reflectors (many Surefire reflectors, plus Arc 4 and Pelican M6 LED reflector) produce superior beam quality over optics. The best reflectors out there have the ability to produce smooth beams with zero artifacts, that balance throw and flood (sidespill).


Most commonly used optics I've used OTOH are all about throw, at the expense of poor beam qualtiy and little usable sidespill. Most optics magnify the artifacts, and at close range the beams are quite ugly. Coronas that have more rings than Saturn (often with different colored rings in LEDs), hotspots that can have square to diamond surround patterns, HUGE voids of black between the hotspot and corona rings, and strange lines and blotches inside the hotspot are common in many of my optics based lights. The TIROS optics that Inovas and the new SF KL1 use tend to produce the nasty rings, and the 30mm optics of the Elektrolumens produce lots of artifacts. When used at long range, these artifacts are not really noticable though, so these lights get used for long range only.

That is not to say that all optics produce terrible quality beams, as my Arc LSHs and Surefire L1s have reasonable beam quality, and also have a good combination of throw to flood. The Surefire L1s are not perfectly smooth, they have bands of different light brightness, but its not as bad as rings. The Arc LSHs have the smoothest beams of all my optics lights, with the main artifact being slightly visible lines in the hotspot.


There seem to be two types of users. Those that want throw and don't care about close range beam quality, and those that want as few artifacts as possible (zero is best). I would take the better beam quality over throw any day. YMMV

Re: Explain to me LED optic\'s, reflector\'s etc,,,,

VG, After removal of the dreaded retaining ring inside of the Lsh you can omit the reapplication of Loc-Tite.This will let you have a relatively easy access to optic and reflector changes from a single light and makes for easy lens changes should it become scratched,etc.. Let one of the modders who contacted you remove the ring though, having the right equipment and experience makes a world of difference.

Re: Explain to me LED optic\'s, reflector\'s etc,,,,

Realistically, an optic can be shaped to do anything a reflector can do. Most optics are shaped to colimate the light, i.e. get all the light more or less on parallel paths. Most optics (NX05, Fraen, etc) are of the TIR type, where light is reflected off the inside of the carefully shaped acrylic. The shape can be changed to provide more spill (NX05 style) or less (Fraen LP style). Most optics focus the light, including any flaws in the light source.

Optics are very sensitive about the placement in relation to the light source. The NX05, for instance, fits right up against the LED. Optics also require that NOTHING touches the back side. When retaining rings touch, they cause rings.

I've noticed actual rings in the surface of cheap reflectors and some cheap optics. I recognize the rings as tool marks from when the molds were made. The tool marks should have been polished away.

The ARC LSH used an NX05 optic. The LSHF uses a Fraen optic. I have one of each in my current EDCs. The Fraen lets the weaker light (19 lumens) throw as far as the stronger one (24 lumens). The stronger light has an NX05 in it.

In short, any light using an NX05 can be adjusted to produce a pretty nice beam. The light should be constructed in such a way that either the LED or optic can be moved to center it. Most reflectors are not as sensitive to left-right centering but are very sensitive to getting the LED at the right height to match the focal point.


Daniel

Re: Explain to me LED optic\'s, reflector\'s etc,,,,

One other thing you have to worry about in the optic is the angles for internal reflection and the refraction index of the material in question - there is the potential for, should the design be poor or the placement be less than ideal, light getting 'lost' inside the optic or being reflected at an angle which renders it useless for your poses, even with the 'flood' optics like the NX05. You can lose as much in there as you would a poorly designed reflector, for much the same reasons.

In reality, yous pays your money and yous takes your chances - though I've found most of the modders here prefer to use reflectors, and good ones, rather than optics. That's probably because of the expense involved in really good optics, as far as placement, design, and materials go. But they're very compact compared to reflectors which do the same thing, and really can concentrate the light.

But for me, I don't always want concentrated light, so out comes the Q-III. /ubbthreads/images/graemlins/grin.gif