I really liked the P900 with it’s 83x optical zoom but could not quite swing for it so I found an awesome deal on the Canon SX60 HS with 65x optical zoom and it’s zoom is stunning but the ISO is not good for night shots like a DSLR camera would be…. I am hoping in the near future they will have a DSLR with the zoom capabilities of the new Hybrid Camera like the P900 and SX60 HS cameras
canon SX60 HS with 65x optical Zoom: https://goo.gl/images/ZdGGYp
Texas_Ace the 4000K sounds good and looks good to me
4000K sounds great for a thrower, due to lower scattering as you mention - and this bin of emitter having a higher lumen output than anticipated is awesome. Hopefully they’re all like that.
I’d like to know why the XHP35-HI was chosen over the XHP35-HD? The reason I ask this is because I was reading over the Cree data/specs on both emitters, and comparing the lumen outputs. The HD series in a 4000K is 40 more lumens versus the HI at same testing specs at 85 Celsius. I imagine it has something to do with the dome on the HD emitters? I’m only asking this for knowledge! Looks to me like the HI series is a de-doomed HD?
I have also searched the web looking for these XHP35-HI emitters, and wow, it appears that they are almost extinct! lol Wondering if Cree will continue to produce them?
The HI version has a flat dome which allows for higher intensity and more throw at the price of a few less lumens.
Best project ever !!! Please put me down for two!
To expand on what Enderman wrote, the round domes that leds have are there to have a magnification effect. It produces more output by making the die seem larger. I think around 50% larger. This is a bad thing for thrower style lights. Just like putting a xhp70 in a thrower style light, the larger die size creates a wider variation of angles against the reflector.
You see, the reflector is designed to bounce light at one specific angle centered on the die.
By removing the dome, the dies true smaller size is revealed. The smaller the die size, the more parallel the beams angles are and the better focused the light is. This is how you get good distance.
Here is a pic that shows it better.
Ideally you’d want a pinpoint light source, but we don’t have that. So we have to find the best compromise in die size to lumen output. Dedomed xp-g2 can make for really long distances, but the hotspot is small and output is weak. Dedomed xhp70 is really bright, but makes for a large hotspot which just can’t travel very far. The XHP35-HI is pretty much the best choice for a thrower light. The hotspot size is decent, plus the brightness is good, plus it’s capable of really long distances.
If you research thrower lights from all the top flashlight companies, they always use the XHP35-HI.
Also, there’s no shortage of them. All the places that sell leds carry them. Mtn Elec has 3 different ones in stock right now. They are not even very expensive. $8 to $10 already reflowed on to a DTP copper mcpcb.
Very happy about the 4000K led 
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.