Question for McGizmo or others with Luxeon side emitter experience

[Doug S]

As you view a side emitter for the side, I presume that the emitted light is spread out some distance along the axis of the device. What is your estimate of the length along which the majority of the light is emitted. I hope this question makes sense to those reading it. The reason for this question is that the greater this distance, the larger the reflector required to produce a given "tightness" of beam.

 

[McGizmo]

Doug,

I tried both the side emitter and standard emitter (both 5W cyans) in the same SureFire Turbo reflector. The resultant center beam was essentially the same size in diameter (no surprise) and the same intensity (this was a surprise!).

Conclusions: With the specific reflector used, the amount of off-axis light provided by both styles of emitters was essentially the same as caught and redirected by the reflector. Due to the constraints of the bench testing and the extreme variation in color, I couldn't assess the differences in beam quality of the wide angle flood resulting from light coming straight out of the LED and not bouncing off the reflector.

Although it is a side emitter, looking directly at the LED, straight on,it is still unpleasant as the light level is quite strong! I will compose and place a post later on what I have discovered so far, for what it's worth.

- Don

 

[Doug S]

Originally posted by McGizmo:


Although it is a side emitter, looking directly at the LED, straight on,it is still unpleasant as the light level is quite strong! I will compose and place a post later on what I have discovered so far, for what it's worth.

- Don

<font size="2" face="Verdana, Arial">I'll bet it is! You will problably need to make this observation at a very low drive level. Yes, please post what you find.

 

[Alan]

Will they make more difference if smaller reflector is used? I guess the side-emitter might win out in small reflector.

Alan

 

[Doug S]

Originally posted by Alan:
Will they make more difference if smaller reflector is used? I guess the side-emitter might win out in small reflector.

Alan

<font size="2" face="Verdana, Arial">I suspect the opposite. I am assuming here that the side emitter emits from a larger apparent area than the HD. I have not yet received confirmation of this.

 

[vcal]

Doug S. (and Don McGizmo)
Q. from a relative Luxeon newby:

Am I right when I assume that when H.D.-high dome is cited, that means the 1 watt-and not the 5 watt?

I.E.-the 5 watt is/will be available Only as a side emitter?
Thanks.

-another Doug S.

 

[McGizmo]

vcal,
in the 1W, there is the high dome, low dome and side emitters (other names for low and high domes but I won't atempt them)

in the 5W there is the high dome and side emitter.

- Don

 

[vcal]

Originally posted by McGizmo:
vcal,
in the 1W, there is the high dome, low dome and side emitters (other names for low and high domes but I won't atempt them)

in the 5W there is the high dome and side emitter.

- Don

<font size="2" face="Verdana, Arial">Thanks for that info...
From reading (most) of the posts on the 5 watt-do you think the side emitter has the most potential for a DIY mod, or would you try to get the (5watt) as a high dome with the optics-for a good quality spot beam.

-OR does it look like a spherical lens is going to be the only answer?
(my questions above refer to only the White emitter)

 

[Doug S]

Originally posted by vcal:

Thanks for that info...
From reading (most) of the posts on the 5 watt-do you think the side emitter has the most potential for a DIY mod, or would you try to get the (5watt) as a high dome with the optics-for a good quality spot beam.

-OR does it look like a spherical lens is going to be the only answer?
(my questions above refer to only the White emitter)

<font size="2" face="Verdana, Arial">I think that collectively we don't know yet but lots of folks here plan to have fun figuring it out. If reflector size were absolutely no object, I believe that the side emitters would have the edge if tight beams were the principal objective.

 

[McGizmo]

Vcal,

I had high hopes in the side emitter but in the two reflectors I tried, the beams were essentially the same with both the HD and side emitter. Any focused optic, Lumiled or acrylic ball, will project the die grid of the colored 5W HD's . The white may be more acceptable as I believe the phosphorus helps "fuzz" the projected image some.

If you want a good quality spot beam, I believe a dimpled reflector is the way to go. It's possible to get good beam with a polished smooth refflector but I think again the white will be a better candidate than the exposed die of the colored LED's. I didn't try a side emitter with a polished reflector and it may be that a smoother beam is possible with this combo.

Hopefully others will report their findings.

 

[Ron Schroeder]

I would suspect that a side emitter would be better with a shallow reflector and a regular emmitter would be better in a deep reflector.

 

[Doug S]

Originally posted by Doug S:
As you view a side emitter for the side, I presume that the emitted light is spread out some distance along the axis of the device. What is your estimate of the length along which the majority of the light is emitted. I hope this question makes sense to those reading it. The reason for this question is that the greater this distance, the larger the reflector required to produce a given "tightness" of beam.

<font size="2" face="Verdana, Arial">Answering my own question: I now have some 1W side emitters to play with. It appears that the majority of the light is emitted along about 2mm length along the vertical axis. This is fairly long, thus if a tight spot is required, a long focal length reflector [i.e., shallow relative to its diameter] would be favored.

 

[Charles Bradshaw]

As an example of polished vs dimpled reflector, I have a Princeton Tec Solo. It came with one of each type of reflector. Using a PR-4 bulb, the polished reflector gives a ring of light with a dark center. This is unacceptable.

With the same bulb in the dimpled reflector, the results were amazing: Nice smooth focus spot and no rings or artifacts! While this is not LED, it certainly illustrates the difference.

My Petzl Zoom has a polished reflector only, and the 3 LED bulb in it produces a dim flood when unfocused, and 3 smaller floods when focused. I think if I were to put a single LED bulb in it, the problem would be solved (LEDCorp has these).

While neither of these are Luxeon, they serve as illustrations.