I set up one of the XHP70 leds on a 20mm star and put it on my big heat sink. I tried out four different reflectors. I dod not raise the led off the srat with copper shims. I wanted to see what would happen for most people, if they just tried to put in a XHP70 and did not have the means to build up the led height above the star.
The heads of the screws are filed down about as far as they can go and the wire is 18ga, with thin insulation. All of that still sticks up higher than the die face and that would be about how you would find in one of the smaller lights, with little room.
The reflectors are a mix of odd stuff. From left to right in the back row - a 50mm Shallow stippled, a 50mm deep SMO, a 60mm very deep SMO. The small one in the foreground is about 25mm and shallow SMO.
As you can see, the reflector sits on the die face. This is what you might find if you are not able to open the reflector up enough to get around the base of the led.
Another reflector with the same problem.
The 60mm deep reflector sat over the die face and almost touched the face of the star. The small reflector also sat down low, but it had tabs that still kept it off the star by about 1mm.
(Sorry, that's SMO, not SOM. Dyslexia gets worse every single day).
Here's what I think. - I think that in order to get a good beam, you will have to use a large diameter deep reflector and you will have to sink that reflector down to the same height as the star, to get rid of most of the artifacts from the four die led. OR, you can use a shallow reflector and have it OP or Stippled, to blend in the defects.
The shallow stippled and the 60mm deep reflectors looked the best. The shallow one gives a large spot that blends out to the edge. The deep one has a defined spot and is almost right. I think if I could get it down that last .5mm to the star, it would be about perfect. Well, as perfect as it's going to get with a four die led.
I also think this will never be a thrower as such. It will give out tons of light and that will make some think it's a thrower, but there is a big difference between a true thrower and a mass of lumens going OTF.