I see! :+1: Thanks for the detailed information! So would it be ok to say that if an XHP70 could be made/manufactured just like an XHP35-HI, but with the lumen output the same as an XHP70, this would be similar to the 35-HI with almost twice the lumen output?
Yes but unfortunately cree doesn’t make that, so people have to “dome-slice” it themselves.
As puting the domes in manufacturing process,is done in a later time,isn’t it possible to put an order to Cree,so as to send several pcs of those XHP70s without the troublemaker domes?
It’s better to think of an led has having a certain number of lumens per square millimeter.
An XHP35 has a 2.35mm by 2.35mm die which is 5.52mm2.
An XHP70 has a 4mm by 4mm die which is 16mm2.
I don’t think the xhp35 is the latest generation like the xhp70.2, so let’s stick to the older xhp70 for comparison purposes.
You can get about 2500 lumen from 5.52mm2 and about 7000 lumen from 16mm. This equates to about 430 to 450 lumen per square millimeter.
The latest generation xhp70.2 can get about 560 lumen per square millimeter. So about a 20% boost. (So in theory, if Cree came out with a new Gen xhp35.2 you might also get about a 20% boost)
To sum it up, the bigger the die, the brighter it can be, but a big die is not good for focusing with a reflector.
There’s more to it, but this gives you a general idea. Maybe Cree will figure out how to make a xhp35.2 soon. :+1:
Not really because the phosphor would get damaged without a dome.
The HI LEDs have a flat silicone layer, not no dome at all.
If you wanted no dome/layer, or wanted a flat layer, you would probably need to contact cree and convince them to make a custom production run for you in which case you would probably be forced to order about 10,000 LEDs or more, so maybe if you have a spare $50k or $100k in your bank account then you can get some custom made cree LEDs 
I think 10K LEDs for Cree is not worth changing manufacturing process for, I would say MOQ would be 500K or even 1M.
BTW, I thought CW led gets us best throw, why then 4000K, can I choos my sample with CW?
Why do you consider the domes on xhp70 a bad thing? I’ve run both and prefer the dome being ON. With the dome sliced off you get a slightly smaller hotspot, but it’s not really worth the loss in lumens.
Here is a pic showing the xhp70 from the same distance. You can see the smaller diameter hotspot on the left. It’s not actually brighter than the right side because the exposure settings were different for each picture. With the dome sliced off the lumen output drops, but you do gain distance. Frankly, I chose the brighter domed emitter and bought a new xhp70 to replace the one I sliced.
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They say NW gives the best throw. CW might give higher output, but the color makes it hard to see through the air over a long distance.
The GT does not come with CW. No worries though, you can buy a new emitter for $10 and drop it in yourself. It’s very easy.
EDIT : This light actually needs a large mcpcb for the reflector to clear the wires. You need a 30+mm 12 volt unit from Maxtoch.
[quote=JasonWW]
Nice, then I can get additional led and try out both
I’m really late at this, hope I can still join the GB?
Thanks!
Thanks again! Perhaps that second gen xhp35 is not too far off…lol
I prefer CW too for my GT.
But if must be in NW, still cant skip this beast.
It’s cheap and easy to change to whatever color temp you want.
It gives higher numbers on paper only. In the real world warmer tints easily throw further. So it depends on if you want higher paper numbers or better real world performance.
Technically if we could get a 2700k LED with the same lumen output (or even less) it would throw even better then this one.
This is why the old incandescent spotlights throw so well with so few lumens, the warmer temps and high CRI really cut through the air.
I am still mad at myself, I had a massive ~12” reflector spotlight at one point with a bad battery so I sold it. Now all I can think is man, that would have been an epic thrower build!
Here is a link to a 9” spot light on ebay…lol…wonder how this reflector would work with the XHP35-HI? A little on the high priced side, but u get free shipping! 
Definitely want/need this for my collection. Sent a comment about 5 weeks ago, but not sure if I’m on the list? Anything else I need to do?
Thanks
Check the first page and press crtl + F and search for your user name, if you are on the list, then you are good to go. If not then it is possible you were missed or your name was spelled wrong when added to the list.
The HID it comes with would throw further due to how it works. The source of light is much smaller then an LED and it puts the light out to the sides making it easier to collimate the beam is the way I understand it.
If I understand the reasoning correctly, CW would throw better in a vacuum, not just on paper. So if you’re buying your GT to use in space during your extravehicular activities, definitely swap out the NW for a CW, right?
And for the humor impaired, this is only semi-serious.
LOL, yes that is quite true. If someone is planning a trip to the ISS then I will personally swap in a CW emitter for your trip.