Optic, Lens or Reflector Help...

Hello changchung

In a Mag-head will fit 4xMcR20 reflectors. Avaiable at the "Shoppe".

Take a look here:

http://candlepowerforums.com/vb/showpost.php?p=1210255&postcount=1

Best regards

____
Tom

Long John said:

Hello changchung

In a Mag-head will fit 4xMcR20 reflectors. Avaiable at the "Shoppe".

Take a look here:

http://candlepowerforums.com/vb/showpost.php?p=1210255&postcount=1

Best regards

____
Tom

Click to expand...

Thanks... But 14$ each???

http://theledguy.chainreactionweb.com/product_info.php?cPath=48_50_64&products_id=464

This one dosent fit too???

http://theledguy.chainreactionweb.com/product_info.php?cPath=48_50_64&products_id=400

They fits too, but the quality of the McR's are better, made of AL instead of plastic.
I don't know, how do you plan to drive the K2's. If you will drive them in the near of 1500mA, I would go with the McR's.
More AL in the head (better heat-transfer) and no risk to melt. And they will last forever, the plastic ones will loose their performance over the years.

Best regards

____
Tom

Long John said:

They fits too, but the quality of the McR's are better, made of AL instead of plastic.
I don't know, how do you plan to drive the K2's. If you will drive them in the near of 1500mA, I would go with the McR's.
More AL in the head (better heat-transfer) and no risk to melt. And they will last forever, the plastic ones will loose their performance over the years.

Best regards


____
Tom

Click to expand...

Thank you very much, good point about the possible melt... i will decide for that option, but i am going to find a better price, think a about it, I pay 8$ by each K2, i am going to almost pay the double by the reflector.???:huh2:

Long John said:

...More AL in the head (better heat-transfer) and no risk to melt. And they will last forever, the plastic ones will loose their performance over the years.

Best regards

____
Tom

Click to expand...

That isn't quite true. Think about it. What part of the LED does the reflector contact? The heat sink? No, it's the plastic part. OK, how about the other end of the reflector. The glass lens. Which, if the light is designed properly, does not interface with the aluminum head directly but rather, through an O-ring, which again, is not thermally conductive. So there is no meaningful thermal benefit to using aluminum reflectors vs plastic ones. If there was any, it's too miniscule to argue about.

I've never heard of a plastic reflector melting due to the heat from an LED. Even in my modified Mag 2D which uses the smooth plastic reflector but with the cam removed, and the LED is biased at 1.2A. No melting plastic here. Going on three years and still as reflective when you compare it to a brand new reflector.

To be honest, the quality of the McR is higher than any plastic reflector. But let's not needlessly downplay the effectiveness of these economy IMS reflectors. They have served many quite well.

Hello CM

I posted only my thoughts. I have no experiences with K2's and no idea, which heat they will produce, driven at 1,5 amps.
But I have experiences with older plastic reflector lights. Mags too and I can say, over the years a chemical substance (I don't know the name in english) of the plastic will evaporante and the reflector will get splits and later cracks.
This must not happen in the first years, but later it will be.
When I'll buy/build a high-end light, I don't look on perhaps 20-30 $ in such a case.
I would go the AL way, that's what I have said.

Best regards

_____
Tom

Long John said:

Hello CM

I posted only my thoughts. I have no experiences with K2's and no idea, which heat they will produce, driven at 1,5 amps.
But I have experiences with older plastic reflector lights. Mags too and I can say, over the years a chemical substance (I don't know the name in english) of the plastic will evaporante and the reflector will get splits and later cracks.
This must not happen in the first years, but later it will be.
When I'll buy/build a high-end light, I don't look on perhaps 20-30 $ in such a case.
I would go the AL way, that's what I have said.

Best regards

_____
Tom

Click to expand...

Tom,

That's interesting on the chemical substance. I have not seen it in any of my lights that use the IMS reflectors. I think you're probably referring to something called outgassing which is a characteristic of any porous material which can absorb (and release) gas. Plastics can outgas but outgassing usually only happens in a vacuum or a low pressure environment. My lights have been stored/exposed in temperatures in excess of 65C (typical temperature inside a car in the desert during the summer) and also have not seen any outgassing or degradation of the plastic reflectors. You must be exposed to some serious caustic environment

CM

CM, the substance is also in plastic tables and chairs for the garden.
After 2-3 years, they will be fragile and a few times happend, after I want to sit down, I was sitting on the floor and the chair was broken.

I'm not a 150kg man.

How old are your IMS reflectors?

Do you want agree, that the McR's are more reliable (lasts longer, no melt, no deforming) and will produce a better beam (more Lux output at the measurement by using the same diameter)?

Best regards

____
Tom

Hi everybody, I do not want to begin a discussion with respect wich is better, Tom is right with respect to that with time fragile can be put the plastics, but that happens through reaction to contcto with the light of the sun, that is rays UV, in this case of being lenses, chromium platings and surfaces with some aluminum layers I do not believe that they are affected...

Long John said:

CM, the substance is also in plastic tables and chairs for the garden.
After 2-3 years, they will be fragile and a few times happend, after I want to sit down, I was sitting on the floor and the chair was broken.

I'm not a 150kg man.

How old are your IMS reflectors?

Do you want agree, that the McR's are more reliable (lasts longer, no melt, no deforming) and will produce a better beam (more Lux output at the measurement by using the same diameter)?

Best regards

____
Tom

Click to expand...

My IMS reflectors are probably three years old, at least as old as when they first came out. As far as your second statement, I will not be baited into saying one is better than the other, something which you seem intent on doing :shrug: I will say both reflectors do a good job. It boils down to personal preferences. Some people prefer Honda's, some people prefer Toyotas Me? I own both :nana: