What is a "deep" reflector good for!?

HEK_Hamburg

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What is a \"deep\" reflector good for!?

Hi!

What is a "deep" reflector good for!?
I know that a "large" reflector is good for throw, but is it the same with a "deep" one?

When I look at my Q3 I note that the Luxeon is pretty deep inside the reflector.

What is that deep reflector for?
 

HEK_Hamburg

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Re: What is a \"deep\" reflector good for!?

Just compare the reflector of the E1e and the Q3!
P0023030_0000009.jpg
 

nerdgineer

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Re: What is a \"deep\" reflector good for!?

I think a deeper reflector reduces the angle of the corona put out by the light so the light will have a smaller "spill". The additional light intercepted by a deeper reflector would - in a well focused light - go towards making the hot spot brighter.

I'm not sure but I think a larger reflector has the capability to focus a distributed (i.e. not a point) light source into a tighter hotspot, so diameter and depth of the reflector together determine its potential for creating a hot spot.
 

Darell

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Re: What is a \"deep\" reflector good for!?

Take a look at the KL6 yead for a deep one too. There are two ways to concentrate the photons better - both involving more surface area. One is to go wide, and the other is to go deep. The wider or deeper you go, the better control you have of all those bouncing photons. Fewer photons escape reflector redirection if you put the source down deeper. In general, the shollower your reflector is for a given source and diameter, the more of a flood you should expect.

And with that, we have reached the ragged edge of my knowledge on the subject, so I'll shut up.
 

McGizmo

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Re: What is a \"deep\" reflector good for!?

what nerdgineer said.

I'll add that the larger the focal length (distance from focal point to base of parabola), the more effective the reflector will be in managing and partially collumating light generated outside of the real focal point. As the focal length increases, unless the depth of the reflector also increases, the angle of captured or redirected light will decrease.

For instance, say you want a reflector that is 1.5" deep. As you increase the focal length, the diameter of that reflector increases. You become more efficient in the management of photons which are reflected but you receive fewer photons with which you have control over and more escape out the front in a direct spill. This is all assuming that the light source has a lambertian distribution like the Luxeon LED's. That is to say that the light is evenly dispursed from 0 to 90 degrees off axis. If the majority of the light is generated off axis or even rearward (think of an incan with frosted tip, then the depth of the reflector at some point will have less effect on reflecting the available light. The Pelican light with inverted LED takes this consideration to the extreme.

Back to the lambertian light source, one must compromise between the use of space (volume) allowed and find an acceptable mix of focal length and diameter which together dictate the depth of the resulting reflective surface. If you play with generating parabolas, you will realize that the variation in focal length has a significant impact on the diameter!

My 27 mm reflector and 38 mm reflector both have the same focal length; the 38 is simply an extension of the reflective surface of the 27 mm. In otherwords, if you shorten the depth of the 38 to that of the 27 by chopping off the front section of the 38, you will end up with the same reflector. In terms of lux, the 38 will typically give you a reading about double that of the 27. If the orange peel on the 38 were smoother like that of the 27, the lux reading would even be higher. The deeper a reflector, the more light you "ram" forward but at some point the beam is possibly too concentrated if spill is also of value.

None of the reflectors we use really collumate the light and there is significant as well as desireable divergence in the beam. If you had a 3" diameter reflector that perfectly columinated the light, you would have a 3" diameter beam at any distance. This would be a very specific and generally useless beam, IMHO.

The TIR optics have greater control over more of the light that is generated in the lambertian LED's but I personally don't care for most of them because of how they place that light. I think we will continue to see improvements in the materials used as well as the designs and resulting beams from these optics. Not only is photon creation in a growing and everchanging technology, I believe that photon management is also young with considerable growth to look forward to! I can't help but think that the scientists and engineers won't be able to alter the reflective and refractive surfaces of the TIR optics to a level where we can take a conventional reflected beam pattern and improve upon it. I can imagine that the very surface of the TIR elements will be treated much like the holographic films now available so that you can get concentrated and yet artifact free beams. I digress...... /ubbthreads/images/graemlins/blush.gif

The simple answer to the posed question in the subject is that a deep reflector manages more of the created photons than does a shallower reflector. Whether this management has the desired results is up to the viewer's determination.
 

Darell

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Re: What is a \"deep\" reflector good for!?

Man, that Don guy sure has a lot of words in 'im. /ubbthreads/images/graemlins/smile.gif

Good point about the deeper one providing the MOST control of the escaping photons. If you had a wide reflector like the dinner plate, even if it were relatively deep, you've got all kinds of wild photons jumping out the front.
 

14C

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Re: What is a \"deep\" reflector good for!?

Might not a "deep" reflector also approach the more ideal parabola? I understand some auto headlights are designed this way.
 

SilverFox

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Re: What is a \"deep\" reflector good for!?

Hello Don,

How does the reflector shape the hot spot of the beam?

I noticed in Bernhard's "Reflector Shoot Out" that the 3 watt beams had more of a pinpoint spot where as the 5 watt beams had a larger hot spot. Is this a function of focus or simply the differences in the light source?

Also, at what distance does the collumated light start following the inverse square law again?

I have been utilizing illumination measurements for years (photography) and it is obvious that when you need more (artificial) illumination, you simple decrease the distance from the light to the subject. With focused light this is not always the case.

I was taught that 1 foot candle measured at 1 foot is equal to 1 lux measured at 1 meter. I recently picked up a light meter that measures in both foot candles and lux. This relationship does not seem to hold true for lights with deeper reflectors. I believe the inverse square law applies to light radiated equally in all directions, but it seems to also work well with lambertian light sources as well. It also seems to apply to reflected light, but at greater distances.

When an illumination measurement is reported (lux), it is possible to "influence" that measurement by adjusting the focus of the reflector?

Tom
 

McGizmo

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Re: What is a \"deep\" reflector good for!?

Tom,

I am certainly no expert; merely an inqusitive student. I can answer to the best of my understanding.

If one had a perfect columating beam and it were in a vacuum where no light were lost to particles in the path, I believe your lux measurement would be the same at any distance. The quantum physics guys might pull out a photon or two (heisenburg uncertainty) or even add some (parallel universe /ubbthreads/images/graemlins/smile.gif ) but for our purposes, there would be no divergence in the beam. The inverse square relies on a lambertian distribution which you do not have if there is any columation or may I call it psuedo columation or bundling of the photon paths. /ubbthreads/images/graemlins/icon3.gif

I believe there is also a certain amont of convergence of light from our typical reflectors. If you take any of the turbo heads and bring the beam close enough to target, you will see a null that does not remain on distant targets. The more effective the columation, I believe the further you will need to go to have convergence of light cover this null that is the shadow if you will of the light source itself. Because of this, I think measuring lux at 1 meter can give false information on some of the seriously columated and far throwing systems.

We don't have perfect columation because our reflective surface is not a perfect parabola and our source of light is not from an infinitely small point, perfectly alligned with the focal point of the reflector. Most of the light produced or photons sent out comes from outside the focal point and as a result these photons are redirected by the reflector but not in columation. The further the photon source is from the focal point, the less it will be columated with photons emanating from the focal point. The greater the displacement from focal point, the greater will be the divergence of the resulting beam, I believe. This is my understanding and explaination of the 5W VS LuxIII beams when both LED's are placed in the same reflector.

Since our image (source of light or luminous die of the LED) is not a single point, we want to arrange the image so that the maximum amount of light generated is closest possible to the focal point. To my way of thinking, this is done by placing the image in the same, perpindicular to the parabolic axis, plane in which the focal point of the parabola lies. If your image size, relative to the focal length of the parabola is large (5W die in small reflector), placing the image on this plane has so much light being generated outside of the focal point that you get a beam so loose in collumation that there is a null in the center. At least this is my current interpretation. /ubbthreads/images/graemlins/smile.gif I have had some success with the 5W in placing the die below the focal point. The other means of blending or randomizing the photon paths to blurr the projection is by the orange peel surface of the reflectors where you have significant surface area that is not true to the parabolic curve. Again, I have digressed! /ubbthreads/images/graemlins/blush.gif

If you use a lambertian Luxeon, 1 or 5W with no collumating device, the rules you learned in photography will still apply.

In terms of "influencing" the lux measurement, if there is any convergence of light in the beam then I would think you could fool the lux measurement in terms of its implication of throw. If lux is measured from the source of light, IE the LED and say at one meter, you could stick a magnifying lense down close to the meter and get a good BS measurement! /ubbthreads/images/graemlins/grin.gif On a similar note, a larger diameter reflector is at a disadvantage in the 1 meter reading over a small diameter reflector because if the two had the same lux reading, the actual divergence from the large diameter reflector is less than that of the small one and its beam will hold to a tighter angle than the small one. The "cone" of light does not have its "point" at the LED but further behind it! If you want to measure the beam angle, the rim of the reflector must fall on the line used in angle measurement, if that makes any sense?? To illustrate take a ridiculous for instance of a 1' diameter reflector compared to a 1" diameter reflector and the beams being measured at 1 meter from the source of light or the front of the reflector. In either case, I believe you will agree that the lux measurements at 1 meter will be a very poor indication of what you might expect at 100 yards!! /ubbthreads/images/graemlins/icon15.gif The 1' diameter reflector would suck big time at one meter but kick A$$ at 100 meters! /ubbthreads/images/graemlins/nana.gif
 

SilverFox

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Re: What is a \"deep\" reflector good for!?

Hello Don,

Thanks.

I'll have to check with my buddies (in a parallel universe) to see if they are aware of the possibilities of added photons... /ubbthreads/images/graemlins/smile.gif

The magnifying glass/candlepower method must be how the hand held spot lights are rated. I wonder if there is a standard power of magnification used...

If I understand you correctly, the reason the hot spot on the 5W is larger than the 3W has more to do with the size of the light source than the focus of the source. Am I close?

Tom
 

McGizmo

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Re: What is a \"deep\" reflector good for!?

[ QUOTE ]
cornkid said:
So one of the new kl1s could outhrow the e2e?

-tom

[/ QUOTE ]

I am not clear how this should follow nor is this the case, in reality. /ubbthreads/images/graemlins/icon3.gif The optic in the X200 has a much tighter beam and further reach but I don't think it will match the E2e (never really compared them). I have been successful in greater throw over the E2e with a LuxIII but it has required a larger diameter reflector.

FWIW, I like to consider myself open to all kinds of irreverent humor but the last line in your sig line just falls way short of being funny. Sorry. It is a "kid" joke though so perhaps it is in sync for you? /ubbthreads/images/graemlins/thinking.gif Just my humble opinion that you did not request so feel free to ignore this completely! /ubbthreads/images/graemlins/blush.gif
 

Cornkid

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Re: What is a \"deep\" reflector good for!?

Confucious says:
" One who stands on toilet, is high on pot."
" One who looks into the business end of a 65 lumen surefire, is temporarily blinded and a stupidhead."
" One who goes to sleep with itchy butt, wakes up with smelly finger."

Ok this is how it works. If you go to sleep with an itchy behind you would be inclined to itch it, right?? Well.... If you itch it, with your hand normally, to be more precise your fingers or thumb, you will have touched your behind with your fingers or thumb..

Your behind is normally stinky.. thats just how the cookie crumbles... I am not a biology major, nor do I care to become one.

So stinky behind + finger (or thumb) = Stinky hand(or thumb)

I am really sorry if this sounds in any way rude.. just wanted to explain my thought pattern at the time. Also... there is nothing wrong with being a kid.... everyone has to be one at one point in time. Its not my choice. My brain is also finishing the highschool-education phase. After I graduate I may be able to be as smart as you.


-tom
 

McGizmo

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Re: What is a \"deep\" reflector good for!?

/ubbthreads/images/graemlins/crackup.gif

Thanks Tom! I actually "got" the joke and how it works, just felt it was a bit anal or banal even for my "sick humor" /ubbthreads/images/graemlins/smile.gif I think this joke has been around for some time now, possibly before you were born. It is on par with how do you break a so and so's finger? A: punch him in the nose or B: kick him in the butt.

Let's hope that when you graduate HS or even before that you are much smarter than I and do something with your brains! /ubbthreads/images/graemlins/smile.gif

OK, this thread is about deep so let's move away from shallow..... /ubbthreads/images/graemlins/nana.gif
 
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