Which Quad LED for 3" Reflector?

[ElectronGuru]

I'm planning a lit'l mod and would appreciate some advice. For a 3-4 volt application, using a 3" FM head/reflector, what is the best/ultimate center mounted LED? Of particular interest is how might die size effect performance with such a large reflector.

Candidate #1, a quad SSC P4: Q7 - large die

Candidate #2, a quad Cree Q5: MC-E - small die

Candidate #3 - ?


This is obviously speculative, but thoughts, opinions, reactions, and links are greatly appreciated.

Thanks!

 

[AlexGT]

To give you an idea, this is how a P7 led driven at 3 amps would look like in a FM 2.5" Reflector.

http://candlepowerforums.com/vb/showthread.php?t=196283

HTH
AlexGT

 

[LukeA]

Dies closer together will throw better.

EDIT: What I mean is that the P7 and MC-E use the same dies, but the MC-E's appear to be closer together.

 

[Gunner12]

They all have the same die size but they ave a different footprint.

Beam pattern with either should be similar to this(look a the P7 beamshots).

 

[LEDninja]

Candidate #3 -
http://www.candlepowerforums.com/vb/showthread.php?t=174207

 

[olrac]

Candidate #3 -
http://www.candlepowerforums.com/vb/showthread.php?t=174207

that's candidate 2 i'm pretty sure

 

[LEDninja]

that's candidate 2 i'm pretty sure

The MCE is 4 die and will be available in a couple of months. The one in the link is single die but have to wait a year or 2 though.
The main advantage of the single die is no need to defocus to get rid of the gaps between dies. Note how the tightly focussed beam of a 4 die LED looks awful. See the last picture in the post.
http://www.candlepowerforums.com/vb/showpost.php?p=2456366&postcount=16

 

[JamisonM]

The MCE is 4 die and will be available in a couple of months. The one in the link is single die but have to wait a year or 2 though.

That's definitely something to look forward to. ElectronGuru, P7's are available and easy to get your hands on right now. The MCE, on the other hand, is a couple of months wait and even then we don't know how easy they're going to be to get a hold of. I'd be perfectly happy with going with a P7 now and then trying out the MCE when they're made available. I'm not sure about simply swapping the two LEDs, but maybe you could buy two heatsinks for each LED, but wire them up the same; with an electrical connector between the LED and driver. That way, all you'd have to do is take out the heatsink/P7 and unplug the connector. When you've got your MCE ready to go just plug it up to the connector and put the heatsink in.

 

[tebore]

Candidate 3 would the 1000-1500 lumen Osram multi-die series of LED.

 

[monkeyboy]

The main advantage of the single die is no need to defocus to get rid of the gaps between dies. Note how the tightly focussed beam of a 4 die LED looks awful. See the last picture in the post.
http://www.candlepowerforums.com/vb/showpost.php?p=2456366&postcount=16

That's what you get through an aspherical lens - an image of the dice. The beam pattern does not look like that with a reflector on its own.

 

[ElectronGuru]

:thanks: Thank you for the input everyone!

In the tradition of CPF, I'm going with both. Q7 in a standard Mag now and MCE for my special project. The real advantage of the larger reflector is throw and that advantage is enhanced by the tighter spacing the MCE offers.

 

[LukeA]

That's what you get through an aspherical lens - an image of the dice. The beam pattern does not look like that with a reflector on its own.

Th P7 has a gap between its dies, so at focus there is a visible cross in the hotspot.