McR27 and XML2

[edeekeos]

Hi guys,

Just put together a few nice Aleph lights, but I just cant seem to get my XML2 LE to focus quite right in the McR27(?) reflector. It's almost as if it's 'just' barely shy of the focal point, but I have no more room left to screw it in, the bottom of the reflector, is hitting the can.

Any thoughts? Any solutions? Any other reflectors for the A1 Head that would be better suited for the XML2 LE? You guys will have to forgive my ignorance, this is my first experience with McGizmo lights.

And the same XML2 led (albeit different LE) in my A2 head, for comparative purposes. It has PERFECT focus..

 

[datiLED]

The LED needs to sit further away from the reflector in the McR27. The dark spot near the opening of the reflector indicates that the LED is sitting too far (or too high) into the reflector. By contrast, the solid yellow reflection in the Aleph1 reflector indicates a perfect focus. Most reflectors will provide a visual clue as to how well the LED is focused by the evenness of the reflection of the phosphor across the reflector surface.

Use an additional spacer to position the light engine slightly further away from the base of the McR27 reflector, and it should focus well. Once the dark ring at the opening of the reflector goes away, and you see a solid yellow reflection over the entire reflector surface, you will find that the beam is perfect.

if the LED is too far away from the reflector opening (sitting too low), there will be little to no yellow reflection showing across the reflector surface.

 

[calipsoii]

Yep, LED sitting too high in the reflector. Build up the base of the reflector a bit. I usually use Kapton tape but I'm sure Scotch tape would work. Put some tape on the bottom and trim it until shaped like a donut. Keep adding tape donuts until it's focused just right.

 

[edeekeos]

Thanks for the response guys, unfortunately that's not my case. It's the entire opposite. The LED is not far enough INTO the reflector. First thing I tried was unscrewing it, and the dark ring in the center just gets bigger until it's gone. I stuck a bare LED on the end of a q-tip, and raised it up into the reflector. In order for the LED to be at the proper focal point, this reflector needs to sit BELOW the substrate of the LED, basically it needs to sit directly on the MCPCB, or even lower. I need a different reflector, or an LED on a pedestal. Any suggestions? I know the Shoppe has three reflectors for this head. The McR-27, McR-27 Seoul, and McR-27 XR. What do I have now, and what other one will be best in this case? I have tried contacting Cindy about the issue as well, still waiting to hear from her..

 

[calipsoii]

Can you lap the reflector on a piece of sandpaper? I've taken a bit off the bottom that way. Get a piece of 600 grit sandpaper and place it on a nice flat surface. Add a little water, then press the reflector nice and flat against it and swirl it around in a circle. Be careful not to get the water/metal grit up into the hole

It's a very slow process but if you only need a couple thousands of an inch taken off that should do it. Otherwise someone with a lathe could chuck it up and turn the bottom off quick and straight.

 

[edeekeos]

Yeah, I guess that would be an option. I have lapped computer processors and heatsinks before. I'm sure I could manage a reflector. However, like you said, my main concern would be foreign debris getting on the reflector surface. I am a SNOB about dirty reflectors! lol

I will try this tonight. I need roughly 1/8'' removed I think. Worse case scenario I'll just buy another reflector I guess. Thanks for the idea!

 

[eala]

Another idea that I found with these reflectors is to simply use smaller die LEDs with them. It focus' those quite well.

eala

 

[edeekeos]

So I did my best to shave a layer from the bottom of the reflector. I think it turned out ok. Reflector surface is for the most part unscathed. It bothers me to have anything 'modded' with this quality of light, but I guess it will have to do. There may be some very slight artifacting from the beam, but it's only noticeable while white wall hunting.

 

[ShineOnYouCrazyDiamond]

Just my opinion, I know Derek and I disagree on this, but the only reflector that works properly with the XM-L2 and XP-G2 leds are the Seoul versions. They focus the LEDs perfectly with a nice spot and nice flood. I've found that the XR and Joker reflectors just don't give an ideal focus regardless of if you pull/push them a bit. Either too much mushy flood or a spot with no flood, etc.

 

[eala]

Your focus looks pretty good to me.

eala

 

[ShineOnYouCrazyDiamond]

The focus s very nice but there doesn't appear to be any corona so the light might be only throw plus spill. I prefer the way the Seoul version give a nice corona around the spot which helps illuminate the peripheral around the spot area.

 

[eala]

The focus s very nice but there doesn't appear to be any corona so the light might be only throw plus spill. I prefer the way the Seoul version give a nice corona around the spot which helps illuminate the peripheral around the spot area.

That is kinda funny. For some reason, I always like that sharper line between the spot and spill. Low corona, I guess. I don't like the beer either.

eala

 

[ShineOnYouCrazyDiamond]

lol - good one eala

 

[wolfy]

I make my Aleph light engines flat then use an XML on a small 10mm base so the LED can poke thru a bit, this seems to give it a good focus on the 27mm and 45mm McR reflectors, because I dont like shaving the bottom of such nice reflectors.

 

[edeekeos]

Yeah, I wish I had the skills to do that. I have seen it done in other instances. I'm very happy with these results though. So far I have achieved perfect focus with both my XML2 LE's, an XR-E, and even my Osram Dragon LE :twothumbs.

 

[wolfy]

Nice looking light by the way.