Interestingly, it doesn’t make as much of a difference as one might think. While copper is much heavier than aluminium, aluminium has a much higher heat capacity per weight unit. After multiplying the heat capacity with the density you get that copper has around 50% more heat capacity per volume compared to aluminium. So a light that runs 30 seconds on high with aluminium will run 45 seconds if it’s made of copper.
But I totally agree with you, I don’t understand all the manufacturers hiding a significant part of the optic behind the bezel. And not just one light but all of them, the Jaxman E2l, the new Astrolux S42, the new Manker E14 ii and the list goes on… By de-shrouding the optic do you mean increasing the inner diameter of the bezel?
I think part of why I see the larger change in the heat up time is that the spacers do not contact the body of the light. So it has to move through the spacer, then the pill and then to the body. All I know is that I can get about 90 seconds on turbo with my EDC S8 triple before it is too hot to comfortably hold.
The optic shrouding is due to none of the lights being designed for the triple optic, they are just reusing other lights and stuff that optic in there.
On top of that there is a practical reason, the only way to hold the optic down is to have a lip over the edge unless you use a glass lens on top of it. Which you would need a good lens to not undo all the gains from the deshrouding.
In my case I took the time to carefully machine out some areas to match the optics and thus hold it in while still giving it full output. It made about a 10% differnce in output but also made it less waterproof.
OK, so I finally got around to building several lights including a triple E2L with XP-G3 4000K 90 CRI and a Skillhunt H03 with Nichia 219C 4000K 90CRI and thought I should share my feedback.
The E2L has the Carclo narrow frosted spot optics.
The Skillhunt has the stock TIR lens.
The Nichia 219C emits a very neutral light without any color shifting. Very clinically clean light with slight deviance towards the warm side of neutral.
The XP-G3, for the same color temperature, is noticeably more yellow and also warmer than the Nichia. There is some color shifting on the outer spill of the light (not an ideal comparison as optics are different).
The XP-G3 is cozier but appears to offset true colors compared to the Nichia. I don’t know how to measure color temperature but if the Nichia is a true 4000K, the XP-G3 feels more like 3500K.
As for using the XP-G3 to see actual things as opposed to white walls, without comparing the beam to any other light, its still pretty awesome. The saturation and contrast from the high CRI and warmer tint make everything look super crisp. The light was built as a cycling specific light with the H17F driver. The extra lumen output is appreciated over the 219C for this particular use. For an everyday EDC to use for up close lighting, I may consider the Nichia a better option for the more neutral hue representation of colors.
In comparison to my Wizard High CRI (about 3000K), the XP-G3 leans heavily towards the yellow, and the Wizard emits a more comfortable orange.
My next project will be an Astrolux S41 with mixed tint (2 x 219C 3500K and 2 x 219C 4000K)… very excited about that one!