# LED retrofit - MR11 vs MR16, does size really matter?



## ohpossum (Dec 19, 2003)

I just got done with yet another Cree/Fatman/Cutter MR11 retrofit (pictures are forthcoming) for a helmet mounted light..and plan to do another retrofit for a bar light.

In the halogen days a MR16 would produce more luminous flux than a MR11 due to its larger bulb and reflector. For the reflectorless LED kit from cutter would there be a difference between an MR11 sized PCB vs the MR16 size? Would the wider spacing of the LEDs on the MR16 PCB have any noticeable effect?

Thanks!


op


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## California L33 (Jul 30, 2005)

That's a good question. I thought the MR16s produced more light for the same wattage because of a better, more precise reflector. If the LED design is reflectorless then I can't see there being any improvement, but I don't know for sure. Does anyone know if the wider LED spacing would increase the light output? My guess would be 'no' but like I said, I just don't know. If you don't get an answer why not do some tests and post the results?


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## StevelKnivel (Jun 23, 2007)

With a 50mm housing (MR16) you have the ability to run independent collimators/reflectors. This lets you adjust the amount of flood vs spot better than you can with the one piece 35mm (MR11) optics. If you were just comparing the one piece MR16 vs MR11 optics I'd be suprised if you could see a performance difference. Check out candlepower forums to see some 50mm triple LEDs with seperate optics.


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## christexan (Jun 1, 2004)

There may be a small improvement on the MR-16, the MR-11 triple-optics are slightly "cut-off" on the outside edge (the cone runs out of room). It's very slight, maybe 5% of the final cone is lost (just a guesstimate), but the MR-16 I believe has the complete cones, and probably more room for more effective TIR angles (don't know if that's true or not but it's within reason to think it might be). Anyhow, I have no facts to base anything on other than the MR-11 does have a slight clipping of the outer edges of the optics, not a big deal and probably not worth worrying about, for the size savings I'll take a tiny loss of output.


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## WeLight (Aug 12, 2007)

christexan said:


> There may be a small improvement on the MR-16, the MR-11 triple-optics are slightly "cut-off" on the outside edge (the cone runs out of room). It's very slight, maybe 5% of the final cone is lost (just a guesstimate), but the MR-16 I believe has the complete cones, and probably more room for more effective TIR angles (don't know if that's true or not but it's within reason to think it might be). Anyhow, I have no facts to base anything on other than the MR-11 does have a slight clipping of the outer edges of the optics, not a big deal and probably not worth worrying about, for the size savings I'll take a tiny loss of output.


Hi
This is Mark from Cutter, I can provide these kits in an MR16 type with board loaded with Q5 and then a user selection of either triple optics, single optics, single mixed optics and reflectors if there was some demand for such a kit. I can also provide this in a 4 up kit with 4 leds ?

Send me some feedback
Cheers
Mark


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