Cree XHP70 up to 4022 Lumens and XHP50 up to 2546 lumens - Multi-die leds.

And time consuming. And, well, organised. Ouch!

Do you mean like HKJs tests or something else?

Yes. Kinda.

In it’s simplest form. It’d be a test of a the top ten 18650s running an XM-L2 direct drive, and generating two graphs. One would be lux/lumens vs time and the other voltage/amps vs time.

I’d do it myself but I don’t have the equipment for data logging, and little time to do it manually.

Someone more skilled in these things than myself might be able to use data similar to HKJ’s measurements to quantify the performance of a cell. The performance of the emitters we use seems very easy to match to a Bezier curve. If both hurdles were dealt with then a simple application could generate what you want as simulations and also take into account an arbitrary amount of resistance at the same time (eg spring resistance / whole light resistance).

Unfortunately while the LED part appears easy, I do not know how to quantify the performance of the cells in the appropriate way.

Hmm. For most of the cells in question HKJ has a “lowest draw” graph (0.2A) and what you might call a “highest properly-behaving” graph with several graphs in between. Sometimes there is an additional outlier graph with significantly worse performance. I’m looking at HKJ’s Efest IMR18650 2500mAh (Purple) 2014 results right now as a case in point. Ugh, again: beyond my skills.

That would take careful plotting and a nice chart to show the curve and peak output/current involved. A cell like the 20R will deliver a lot more initially, and of course die faster because of it. With more than 50% more capacity, the BD wouldn’t start at the same power level and of course would die a much slower death. It would be interesting to see exactly where the trade-offs were though. Just how much more output does the hotter cell have and where do the lines cross?

For me, out here in the country, the initial performance is of high value. An example would be last night. I was out taking a few beamshots when somebody drove down the country road shooting out the window of their pick-up. I put a fairly healthy amount of light on em and tracked em from 300+ yds for about a half mile so they’d know without a doubt they had been observed. I got a description of the vehicle, but my camera couldn’t get the plate number at the distances involved. That initial burst of output though is what I typically rely on. For the critturs and such we have out here, be it coyotes with 4 or 2 legs.

It is not shallow it is just the pics, it is even deeper than the COURUI reflector that is 70.5mm wide x 47mm deep , and it was in an old Osram flashlight for incandescent bulb and it is easy to mod for led use

It looks too shallow for how wide it is. The incans use a bowl shape instead of a parabola, not usually well adapted to LED use with the possible exception of the big MT-G2. I don’t know how it’d work with the XHP70, but it might be worth a shot…

I know you ment specifically for this reflector, and since some specialty flood reflectors aren’t actually paraboloid in nature you may be right here. But I just want to clarify this point because I know some people are prone to getting confused when it comes to picking reflectors and the actual differences between reflectors intended for incans vs ones intended for led use.

Ultimately there’s really no geometric difference between a paraboloid reflector intended for incan use vs one designed with an led in mind.

You’ll find incans designed for throw will also use a paraboloid reflector, the only difference is that the light emitting “surface” of an incan bulb is a thin filament suspended essentially in mid air and not a flat surface that by necessity of heatsinking is best placed at the end of the reflector. The filament is also emitting light in all directions vs an led which only emits light over a 180 degree area (at best).

Because of these two factors an incan bulb can take advantage of a parabolic reflector that has it’s focal point further towards the front of the light, this automatically makes the base of the reflector look more bowl shaped. At the same time it acts something like a recoil reflector by also catching and projecting any light that gets emitted backwards from the filament.
For LED reflectors we are simply cutting off or flattening out the useless bowl end of the paraboloid, this is usually done right at the focal plane of the parabola since leds don’t emit light behind themselves.

Simply taking a reflector designed for incan use and placing an led at the base of the bowl will not project a good beam, since the led would be badly out of focus.
However, raising that emitter on a pedestal to the center of where the incan bulb filament would have been (the focal point of the parabola) will project a perfect hotspot.
As would turning down the end of the incan reflector past the focal plane or course.

It’s all about getting the light emitting object as close as possible to the focal point of the reflector, or in the case of a quad die emitter…very slightly out of focus :wink:

Here’s some quick examples I made up, since I’m just in the process of fiddling with all things reflectors in 3d software. :slight_smile:

Both of these reflectors are based of a single complete paraboloid surface, the only thing different is how the end of the reflector past the focal point is treated.

Below is what these two reflectors would look like in 3d, again absolutely identical except what goes on past the focal plane. Look remarkably different don’t they?

Shows how an incan and led specific reflector can look very different, have a different perceived depth and one may look more “bowl” like than the other but are in fact absolutely identical geometrically and therefore also identical in how they project a beam.

thank you LinusHofmann nice info , well a while ago i modded a plastic host to be my 1st thrower and i did what LinusHofmann explained

there you will see the incan reflector i modded

And yes DBCstm it seems shallow for how wide it is but it is fun to try, and while i am waiting to the XHP70 to be available ( please hurry up HANK :* ) i will try it with an MK-R i just received from FT

Very impressive output increases!

I wonder what the Cree XHP70 beam pattern would look like if it had a lens over it like this OSRAM?

http://www.digikey.com/product-detail/en/LE%20UW%20E3B-PZQZ-4C8F/475-1295-ND/1739225

Working on fine tuning, but I just stuck the XHP70 in an old Solarforce Skyline I. The super deep reflector really gives this bad boy a tight hotspot! :bigsmile:

OH, brace yourselves….The SinkPAD Aluminum DTP MK-R star is $1.00 apiece with a $45.00 minimum. On hand and ready to go. AND, they will have copper MK-R stars by next week or so. $2.50 each at minimum, $75. Price break at 300. The minimum is about 40 stars. Cool beans eh? :slight_smile:

I’d like to get in on that! :slight_smile:

What about 5000K emitters mounted?

That’s a different ballgame.

The old Skyline I is now making 3046 lumens from 6.68A out of 2 Efest Purple 18350’s. Tighter hot spot than the Olight and far tighter than the X6. Still has a bit of an X in the middle, gonna see if I can dial that out.

This one I put the XHP70 on a 26mm MAXToch copper mcpcb. Cut a groove beside the thermal pad to narrow it down, filled the groove with Arctic Alumina Thermal Adhesive. When the AA dried, I shaved it off with an Xacto for an even smooth surface, then used strips of copper sheet to mount the emitter. The negative wanted to touch ground somewhere and I had to re-flow it, but after that it was fine.

Nobody has tested the XHP50 yet?

I think I’m going to plan a P60 with it. I was going to do MT-G2, but the XHP50 is comparatively cheap. I’m sure the beam will be hideous, but the overall lumen output should make up for it.

I put the XHP70 on a 32mm Noctigon to go into the Shadow JM26. With the DQG 6A boost driver intended for the Tiny Triple it runs on a single 26650! 2.64A at the battery, looping for the clamp meter from battery negative to ground ring on the driver.

1.5 lumens low
100 med
404 high
1373 Turbo

Now if I can just get that donut hole out of the beam…

Wow, I think this is your third light you have managed to put a xhp70 in! Nice work.
I have heard people turning their reflecters op. Forgot how they did it or what they used. That might do the trick for removing that donut hole…

is there a good source for these XHP’s? i looked a mouser but its 20 euros shipping, a little (a lot) to pricy for me. or if a member is willing to sell me one (to europe), that would be great? :slight_smile: