blue and green XP-E2, output tests

Flashlight Modding and DIY Parts
18

I know this is an old thread, but valuable none-the-less! Thanx djozz! Couple of Q's:

  • I know you have a much better light meter than most of us, not sure what meter you used to do these tests?
  • with my cheap meter, I definitely measured green brighter than red with both XML color LED's and XP-E2's. Any chance you can re-visit the green test?

Fyi... First I ordered color XP-E2's from DigiKey, the realized later these are bin rated, and Mouser has better ones Frown. So, I ordered various top bin color XP-E2's from Mouser and just got them in. The bin specs were quite good:

Red - P3 (same as DigiKey, same as yours)

Blue - M3 (Mouser - same as your)

Green - R3 (Mouser - 1 up from yours)

Royal Blue - 37 (Mouser - whatever this bin means)

Red-Orange - Q4 (Mouser)

Amber - Q4 (Mouser)

I mounted a green R3 and red-orange Q4 on 16 mm Noctigons and built up pills for a UF-1504 to run at 2.48A (6*350mA 7135 + 1 380mA 7135). My intention is max throw. Measuring with my $35 light meter, I got the following for lumens in full flood, throw in full zoom-in:

Green R3 in UF-1405, 2.48A: 211 lumens (@30 secs), 160 kcd (800 meters)

Red-Orange Q4 in UF-1405, 2.48A: 119 lumens (@30 secs), 85 kcd (583 meters)

The lumens are pretty low - could be the poor aspheric flood mode of the light/lens, not sure...

In use outdoors, the green in full zoom is like a laser beam, while the red-orange's beam can hardly be made out. Lighting up a tree about 80 meters away though, the red-orange looks pretty darn bright compared to the green, maybe about the same (double the kcd though isn't much difference). Also note the red-orange looks pretty much exactly like red I've seen on other LED's/flashlights - I could not tell the difference. The red-orange's dye looks exactly like a red dye in both color and having the lines on it (like a XP-E/XM-L, etc.).

The cheap spare pills available for the 1405's is great by the way for testing/comparing. I bought 2 UF-1405 hosts and 2 spare aluminum pills from GearBest. The pills were $1.50 when I ordered - now see them listed at $2.50 (should have ordered more). The aluminum pills fit great and actually have more threads than the brass stock ones.

19

In the 1504, running a red XP-E2 P3 at 2.4A, I was able to see with my naked eye objects at 400 yards. I tested the green too but I hate using green to hunt so I don’t even recall how well it did. Green seems to be affected so much more by fog and moisture and dust.

20

Updated my posted with throw distances. Ok - cool! Glad to hear you have a red in a 1504. Practical use/results right now seems to be the best - not sure how red's are handled in my light meter. I thought the red looked better outdoors than on my meter.

I'm using the green just for kicks - freaks people out when you shine it in the sky where there's always 1-2 planes in our area. It's hard to convince them it's not a laser.

Have you de-domed a red or any color XP-E2? Wondering if they come out same way as the whites - better throw, less lumens. Can't recall seeing it posted.

21

I posted it in a thread where I tested a bunch of LED’s. I did get more kcd but not as significant as white LED’s.

22

Ahh - ok, sounds familiar now so I probably forgot it. If you can locate it, or if you got any #'s saved, would appreciate it. Interested bout tint shift, if any, too.

23

It’s buried in here somewhere. I don’t recall any tint shift. I do recall that dedoming the red was a real PITA and required a fair amount of heat. The dome just didn’t want to let go.

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Ohhh yes, stupid me. Forgot you did al those 1504 tests! Interesting read in the thread, btw...

25

@Tom: it must be fun to have a 1504 pill for every colour.

I used my chinese Tondaj luxmeter still, in these colour XP-E2 tests. I see I did make a reservation for a wavelength error in the OP at the time, but it is even worse than I thought then: compared to my high quality luxmeter, the Tondaj reads 4 times (!!) too high in blue, 20% high in red, green is about right (as is neutral white btw, see my 'luxmeters, thoughts and findings' thread).

26

So the revised graph looks like…

27

Morally, you are right, but I would have dive into the excel- sheet again for that, it takes time, effort, and it is boring . This is a hobby, with in my case limited time, and I like it to be as much fun as I get away with.

Apart from that, the most interesting aspects of the graphs for me are the current/output behaviour and the output relative to other leds of the same wavelength , The absolute lumenvalues are of less interest, I think.

28

Maybe this will be interesting to someone.
I was preparing some red XP-E2 leds, dedoming them and I managed to rip of one bond wire from emitter, I tested it later and it still worked with one wire only but it was pulling only 1,9A out of ~2,4A that driver can deliver. Tested same driver on undamaged emitter and I got 2,4A as expected and anticipated. So, not all is lost if you screw up one bond wire on a emitter :slight_smile:

29

It’s not really surprising that the green emitter falls off so much at higher drive currents. The thermal resistance for green is 15°C/W. Other colored emitters have a thermal resistance of 5-9°C. The unusual results is the plot for the red emitter…even though, red will typically have lower initial efficiency, with a thermal resistance of only 5°C/W, it should have pushed very well.

So much of the issue with determining the output of colored emitters (and varying tints of white emitters) is the spectral sensitivity of the light meter. Since green is near the center of the photopic luminous efficiency curve, it can be measured without much adjustment. Red and blue have to be factored heavily to determine come close to actual luminous flux using a CIE filtered meter.

30

Apart from the thermal resistance, there is a inherent effect of led type: red led output suffers way more from heating up than green and blue

Btw, in later tests I used a better luxmeter, one that does have a much better colour filter. It does not overrate blue and red so much.

31

I think here are some users, who can help me :)
A friend asked me a longer time ago to build him a green LED flashlight for hunting.
I combined a green Cree XP-E LED, alu base, dedomed it, use 3x 7135 AMC driver and a Convoy C8. Now he asked if I could modd it a little bit more. After this, I soldered another 7135 AMC on the driver and use a 4x 7135 driver with a UF T20. Both worked well.
He uses it for 20-25 minutes nonstop. Has anyone tested the older green XP-E with 1,75A or 2,1A for round about 25 minutes in one of these flashlights?



32

Has anyone gotten a photo red Xp-e2 yet? I have some, but no way to test other than a DMM really. If the data sheet shows them at 2.42vf and the regular red 2.65 @ 1000mah, what's your best guess on the vf and safe over-current for the photo red (on dtp copper)? Think it'll take 2.2ah like the old xp-e2 red did, but now with lower vf according to the datat sheet? Speculation welcome, or advice on how to test/get some data with minimal equipment and skill. Thanks!

https://www.cree.com/led-components/media/documents/XLampXPE2.pdf

Xp-e2, page 3 has vf data for photo red and old-style red xp-e2.

33

Yes i have already one brinyte b158 with xp-e2 deep red made its very very good i drive it at 2.6 Amp no problems ,not become hot. now thats REAL red .
Also have a little trower made with dedome led.

34

Cutter au has a “NEW Product Release: Latest Version of the Cree Photo Red 660nm, now in XPG-3. This is a preorder, stock available late May 2019”

link to product page: https://www.cutter.com.au/product/xpgdpr-l1-0000-00g01/

According to the official spreadsheet the red XPG-3 can handle 1.5A max and the XP-E2 1.0A.

I wonder how much the XPG-3 could get max and how it compares to the XP-E2, which can get ~2.5A as measured here.

Djozz are you going to measure them?

I’ll throw a triple board in the FWA3 with 50% fet reduction firmware.

35

If I can get them for a reasonable price, yes I will test them (although I have no comparison previous 660nm leds to check the output against).

Cutter always had high shipping rates, not sure about now. They are also listed at Mouser (not in stock yet either), perhaps that could be an option, together with other leds to make shipping reasonable.

36

cutter has free shipping if I’m not wrong

37

Cutter has been traditionally high in shipping, for years, and don't see any recent change in that policy. They get no retailer savings from anyone, so have to pay full price and they are more set up for wholesale than retail.

Their high shipping costs are remarkably reasonable when you crank on the qty you order, as a reseller would order.