1. Re: ZebraLight H502 XM-L

Originally Posted by YoSeKi
Could you clarify?
The light intensity of the 502 will only be 64% of the H501, if the light is evenly distributed about the whole beam circle.

2. Re: ZebraLight H502 XM-L

Originally Posted by Photonrunner
The light intensity of the 502 will only be 64% of the H501, if the light is evenly distributed about the whole beam circle.
Speaking as someone that owns both lights i can say with 100% conviction that the H502 is dramatically brighter than my H501.
In fact my H502d (170 lumens) is dramatically brighter than my H501w.

Again this is where i'm struggling to understand the requests for a narrower beam spread on the H502.
It really really does not need it in any situation i've used the light (and that is several hours over the past few weeks)

3. Re: ZebraLight H502 XM-L

If you do the math assuming the 502 and 501 evenly distribute there lumens the beam intensity is higher on the 96 lumen 80deg beam than the 260 120deg beam. I don't have the 502 primarily because of this reason. so I can't do a real world comparison. However I run a lot with my 501 and it's sufficient for road running at decent clip 5:30/mi to 6:00/mi If I go on trails I bring something in hand with a little more throw. This is why I would love a 502 80 deg 260 lumen head lamp. Would like more throw to see obstacles further ahead. I haven't tried the 502 due to my scepticism of the 120deg beam, but perhaps I'm wrong and it's sufficient light or better than the 501. Would like to hear a real world comparison for running if someone has the time and both models.

4. Re: ZebraLight H502 XM-L

Originally Posted by kwak
Speaking as someone that owns both lights i can say with 100% conviction that the H502 is dramatically brighter than my H501.
In fact my H502d (170 lumens) is dramatically brighter than my H501w.

Again this is where i'm struggling to understand the requests for a narrower beam spread on the H502.
It really really does not need it in any situation i've used the light (and that is several hours over the past few weeks)
the idea is MORE not less I think.
80degree with more lux/brightness @ any given level as opposed to less lux and more spread @ 120

the 501 has a different driver and emitter so its hard to compare maximums.

some people might prefer (myself included) having the extra flood concentrated into a beam that is similar to the H501 but
with the more efficient emitter and better ergonomics of the H502

also - does there need to be 2 threads on this?

5. Re: ZebraLight H502 XM-L

Originally Posted by Photonrunner
The light intensity of the 502 will only be 64% of the H501, if the light is evenly distributed about the whole beam circle.
How did you get that figure, 64%?

6. Re: ZebraLight H502 XM-L

Originally Posted by kwak
Speaking as someone that owns both lights i can say with 100% conviction that the H502 is dramatically brighter than my H501.
In fact my H502d (170 lumens) is dramatically brighter than my H501w.

Again this is where i'm struggling to understand the requests for a narrower beam spread on the H502.
It really really does not need it in any situation i've used the light (and that is several hours over the past few weeks)
Comparing brightness may depend on the environment you are doing the comparison. For instance if you compare brightness in a confined space you may get a lot of light reflection back into your field of vision. If your outside with nothing around the results might be quite different. Would be interested in a comparison outside without walls/ceilings reflecting light back.

7. Re: ZebraLight H502 XM-L

Originally Posted by YoSeKi
How did you get that figure, 64%?
a 120 deg beam circle area is 4.26 times larger than a 80deg beam circle area.
So divide the lumens by area
(502 lumens / 120deg circle area) / (501 lumens / 80deg circle area ) =
(502 Lumens / 501 Lumens) * (80deg circle area / 120 deg circle area) =
(260/96) *(1/4.26) =
260/(96*4.26) = .64 the intensity of the 501 or 64% the intensity.

8. Re: ZebraLight H502 XM-L

Maybe someone has both the H60 and the H502 and would compare them side by side for us. H60 (190 lumens, 80 degrees, positive meniscus lens) would make good comparison to see if a collimating lens gives better throw in real life.

9. Re: ZebraLight H502 XM-L

ordered a H502d! However, I'm a bit worried at how green it might look, given by how green it looks on Esko's picture...

Originally Posted by Photonrunner
a 120 deg beam circle area is 4.26 times larger than a 80deg beam circle area.
So divide the lumens by area
(502 lumens / 120deg circle area) / (501 lumens / 80deg circle area ) =
(502 Lumens / 501 Lumens) * (80deg circle area / 120 deg circle area) =
(260/96) *(1/4.26) =
260/(96*4.26) = .64 the intensity of the 501 or 64% the intensity.
you're assuming the light is evenly distributed across the entire circle of illumination; however its been pointed out multiple times that the light output is NOT even. There's a distribution gradient that's even available by the Cree information pdfs on their website.

YoSeKi has had experience with the XM-Ls and has also stated that it is approximately 70% output within an 80ş arc.

10. Re: ZebraLight H502 XM-L

Originally Posted by Surnia
YoSeKi has had experience with the XM-Ls and has also stated that it is approximately 70% output within an 80ş arc.
I urge everyone, regarding everything, to not draw conclusions until you see for yourself.

Assumptions can be wrong and trying to account for all of the variables in theory might not reflect reality.

Don't just believe what some stranger on the internet tells you either. Especially me! Because even if he has experience with something, he might not perceive or prefer things the way you do.

Some things you just have to see for yourself.

PS: 1000th post of the thread!!

11. Re: ZebraLight H502 XM-L

Originally Posted by YoSeKi
I urge everyone, regarding everything, to not draw conclusions until you see for yourself.
yah we need someone to point these little buggers @ a lux meter

the thing is - H60 is a different emitter than 502

an accurate test would require the same drivers + emitters and different optics or no optic etc.

12. Re: ZebraLight H502 XM-L

Originally Posted by Surnia
ordered a H502d! However, I'm a bit worried at how green it might look, given by how green it looks on Esko's picture...

you're assuming the light is evenly distributed across the entire circle of illumination; however its been pointed out multiple times that the light output is NOT even. There's a distribution gradient that's even available by the Cree information pdfs on their website.

YoSeKi has had experience with the XM-Ls and has also stated that it is approximately 70% output within an 80ş arc.
I've stated in my previous posts this number assumes even distribution, which in my opinion should be a reasonable assumption for a flood light. I was answering YoSeki's question on the actual calculation.

I'd be interested in seeing how the 70% number in the80deg arc was arrived at. Would appreciate any details on how this was arrived at. ~3/4 of the output in 1/4 of the beam area is not very even for a flood light.

13. Re: ZebraLight H502 XM-L

Originally Posted by Photonrunner
I've stated in my previous posts this number assumes even distribution, which in my opinion should be a reasonable assumption for a flood light. I was answering YoSeki's question on the actual calculation.

I'd be interested in seeing how the 70% number in the80deg arc was arrived at. Would appreciate any details on how this was arrived at. ~3/4 of the output in 1/4 of the beam area is not very even for a flood light.
I believe thats the standard light distribution of the XML.

14. Re: ZebraLight H502 XM-L

Originally Posted by YoSeKi
However, 40-50% is a low estimate. Having worked with bare emitters, I can say that most of the useful light from an XML is inside the middle 80 degrees. I stand by my earlier estimate that about 70% of the useful light is in the middle 80 degrees.
Yet the best Zebralight throwers (like SC600) use that almost useless light to create the hot spot. They are listed as having a 80 degree spill (the center beam) and 10 degree hot spot (the collimated beam from the rest of the led emission).

Aspherical throwers often lose most of the led output because they only use the center beam. The aspheric version of the new Crelant thrower has only a small intensity gain compared to the reflector version. Aspheric lens uses the center beam. The reflector version uses the side spill, creating an almost as bright (but also wider) hotspot as the aspheric version (+the reflectored one has also spill, unlike the aspheric one).

Originally Posted by YoSeKi
A biconvex, plano convex, or positive meniscus lens would be able to narrow the 120 degree beam into an 80 degree beam. But one of the complaints about the H502 is that it has a faint hotspot, and the lens would only narrow, and not even out, the beam. The hotspot effect would only be accentuated.

A parabolic reflector would create a hotspot. An ellipical reflector would create rings in the beam. I'm not entirely sure what a conical reflector would do, but I think that a highly reflective conical reflector would create a hotspot or rings of some form.

Maybe a custom aspheric that takes the outer 20 degree ring and evenly fills in the inner 80 degrees would do the trick? But I doubt it would improve throw a noticeable amount.

Those are the only optical options I can think of. Are there others that I missed?
A plano convex lens was the original plan.

Well, I am not an illumination designer, and certainly not a reflector or lens designer. But lets ad the custom shape reflectors, TIR lenses (like in Preon P0), matte finishes, white surface instead of mirror (practically the same efficiency but less directional), orange peel, very small reflectors compared to the led size (compare it to DEFT), partly transparent parts (like the current GITD reflector) etc. And the combinations of the different solutions.

15. Re: ZebraLight H502 XM-L

Originally Posted by srfreddy
I believe thats the standard light distribution of the XML.
I see thanks for the response. Does the 502 just use the bare emitter distribution? I thought they were going to have a lens to even out distribution.

16. Re: ZebraLight H502 XM-L

I just received my H502d so I figure I butt in to give my impression. I own Surefire LX2 & Sunwayman V10 Ti original (not XML) and briefly own ZL H31F before I return and exchange for H502d. As you know I do not own many lights and inexperience to compare with many models.

Size: I didn't get "surprised" when i receive H502d. I sure did when I received H31F. Due to battery size difference, Comparing size to H31F is kinda Apple vs Orange. H502d sure is small and descent. H31F being noticeable smaller, the same time, it is a bit too small to be comfortably operate. My hand is already tiny as an adult. I have female size hand. Although I didn't get the initial excitement from H502d's size, it is more comfortable to operate that I don't feel afraid I will accidentally drop it.

Flood & Floody: Briefly own H31F and now own H502d I finally get the first hand experience the difference between the two. H502d is wider. Pretty amazing coverage from this little light. I sure understand why H502d is not a distance player. H31F doesn't provide as wide coverage. As much I love H502d coverage, I do wish it could light brighter at farther distance as H31F would but that is the trade off. My NYC living room is only 15ft X 10ft. At maximum distance, already feel it is not as bright as I wish. With that said, I am able to see everything clearly in 15ft. Just not that bright. This light is tiny, already impressive amount of light it put out.

Color Tint: This seems to be most of my concern. I shoot a lot of still live product photo and some time wish to fill light. H31F has blue-ish cool tint. To be honest, terrible rendering product color. It makes product color with purple color on top of products original colors. Main reason I return it. To work H502d with 100W light bulb together, H502d color tint appear to be slight cool at distance but no harsh purple color. At close rage, H502d fill the light really well. The cool color goes away. You only feel H502d color rendering is consider cool at 2ft or more distance. To work H502d with single Fluorescent (they call it daylight) together, H502d fill the light really well. At 1ft distance, it appear brighter than my fluorescent light on HIGH. The color tint appear to be less blue than the Fluorescent light source. Perfect light to fill at distance or close range. My photography under the same fluorescent with WB:daylight has been fantastic result. i have no doubt my H502d will be a good future side kick.

White wall hunting: This is most ppl's concern and unsure of. The reason is simple, because the light tint does change to eyes and it is hard to explain why since I am no scientist. Easier to understand when you see it yourself. Here I'll try to explain the best I can. In pure darkness in a white 15ft x 10ft room with only H502d on high. At distance 10ft+, the light tint appear or feel like it is cool. Because definitely no yellow tint. There is no purple/blue-ish tint. You can fairly say, it is WHITE, white. Because there is no warm/cool tint, the color do feel cold. At palm width distance to wall, H502d appear to be cool-ish white at center and a hint of green at end outer rim. At finger length distance to wall, and compare side by side with LX2 and V10R. H502d in comparison the beam tint appear to be warm. It appear slight warm in color. That is what makes H502d tint tricky to describe.

Sum it up: IMHO, I don't think it is GITD that give out a hint of green at outter rim. Not scientific proof of course. I as I said, H502d at finger length looks slightly warm and when you back a little farther, due to not enough brightness at outer rim, the hint of warmness became green-ish on white wall. When back it out a lot more, the hint of warmness goes away not noticeable at all to eyes and became over all white/white. Because the white is so pure, eyes will proceed the color as cool feel. The end of the day, less likely anyone will use H502d at finger distance or palm distance will feel the light is behave on the cool side overall. I will bring this light to camping this weekend. I'll feed you guys more of my personal experience using it in the wild. As short distance for fill light photography, this light tint perhaps is my best bet for the purpose. Personally, I def will not buy another Zebralight Cool tint light in the future. Even they are so much brighter. I just hate the color. BTW...the pocket clip is hard on Zebralight. I was moving it slightly around, the clip do scratch the light finish...

17. Re: ZebraLight H502 XM-L

LEDs aren't flood lights [pure point sources] unless they are de-domed.
The H501 & H502 use their own means of controlling distribution.
So the H502 is more versatile with the wider distribution, unless the extra beam angle causes glare with eyeglasses.

But for running, why not just use the H51Fw? I re-routed Zebralight's inferior band system so the silicone holder no longer just hangs off the headband, and bounces with each step. [I will still acquire the NiteIze headband in the future].
I just tested my H31Fw outside, and the 35 lumen mode is plenty bright on brown-ish midwestern grass [perfect for jogging pace]. The 98 lumen is gratuitously bright [running], and the 180 lumen mode seems bright enough for a sprint.
So an H51Fw with an Energizer L91 should give 3.5 hours on its 82 lumen mode, and 2.5 hours on its 115 lumen mode. So how fast is your marathon pace? [would the TI crAA 14505 possibly last even longer due to higher voltage, and hence higher circuit efficiency?]

18. Re: ZebraLight H502 XM-L

Originally Posted by MichaelW
LEDs aren't flood lights [pure point sources] unless they are de-domed.
The H501 & H502 use their own means of controlling distribution.
So the H502 is more versatile with the wider distribution, unless the extra beam angle causes glare with eyeglasses.

But for running, why not just use the H51Fw? I re-routed Zebralight's inferior band system so the silicone holder no longer just hangs off the headband, and bounces with each step. [I will still acquire the NiteIze headband in the future].
I just tested my H31Fw outside, and the 35 lumen mode is plenty bright on brown-ish midwestern grass [perfect for jogging pace]. The 98 lumen is gratuitously bright [running], and the 180 lumen mode seems bright enough for a sprint.
So an H51Fw with an Energizer L91 should give 3.5 hours on its 82 lumen mode, and 2.5 hours on its 115 lumen mode. So how fast is your marathon pace? [would the TI crAA 14505 possibly last even longer due to higher voltage, and hence higher circuit efficiency?]
I have the H51 and use it sometimes but like the 501 better due to less bounce and no hot spot. I didn't bother getting the H51FW due to its larger size. But as you pointed out maybe i could experiment with a different headband setup to minimise bouncing. How did you do the rerouting of the headband? I may give that a shot if it helps the bouncing. Would be curious about the NiteIze too if anyone can chime in on that for running. I agree the 98 lumens is bright enough for most situations, however on trails or areas with more terrain changes I would like to see a bit further ahead so something doesn't come up on me to fast. Typically train 100 to 150 MPW at ~6:00 to 5:30 pace, my marathon PR is 5:28 pace, so far but think I can hit 5:20 pace if I get a good one. I like to stick with enloops L91's would get expensive quick, and any LI battery scares me enough to keep off my head!

19. Re: ZebraLight H502 XM-L

My above H502d review is perform with Energizer Ultimate Lithium x9 (improved) batteries. Man, they are mad expensive. \$15 for 4. I thought CR123 was pricy.....
Question, Is AA lithium really perform that much better over Energizer Alkaline or Energizer Max batteries in term of performance time and brightness? If not, I prob should run it with Alkaline AA or not as expensive Lithium batteries. What you guys recommendation for AA batteries run on ZL?

20. Re: ZebraLight H502 XM-L

Originally Posted by wuyeah
My above H502d review is perform with Energizer Ultimate Lithium x9 (improved) batteries. Man, they are mad expensive. \$15 for 4. I thought CR123 was pricy.....
Question, Is AA lithium really perform that much better over Energizer Alkaline or Energizer Max batteries in term of performance time and brightness? If not, I prob should run it with Alkaline AA or not as expensive Lithium batteries. What you guys recommendation for AA batteries run on ZL?
I run Enloops or Duraloops. IMHO Nickle Metal Hydride rechargeable's are the most economical solution for ZL's. Heck the new enloops give you ~1300 hours (1500 recharges ) at max off of one AA!

21. Re: ZebraLight H502 XM-L

Originally Posted by Photonrunner
I'd be interested in seeing how the 70% number in the80deg arc was arrived at. Would appreciate any details on how this was arrived at. ~3/4 of the output in 1/4 of the beam area is not very even for a flood light.
Its a misunderstanding of the cree spec sheet. There are actually multiple mistakes being made.

Firstly the h502 has a total of 120 degree spread, that is 60 degrees either side of centre.

Head on (0 degrees), the xm-l's output is obviously at the peak of its distribution (100%).

At a 40 degree angle either side of centre (80 degrees total, ie a h501), the XM-L is at ~85% of peak intensity. So you wouldn't notice this small falloff in general.

At 60 degrees either side of center (120 degrees total, ie a h502), its intensity is 55% of the peak which you will notice only a little bit. This also does NOT mean that 55% of the light is in the 120 degree spread, just that at a 60 degree angle the lux is 55% that of 0 degrees - see further below.

At 80 degrees either side of centre (160 degrees total), its intensity is just 15% of the peak. This is a total 160 degree spread, not 80 degrees. The 15% is a measurement of lux at that angle, not lumens that are output at more than 80 degrees off centre.

None of this takes into account any kind of lenses or reflectors, its purely what comes out of the led.

To calculate the proportion of lumens coming out at different angles needs a bit of math. Using rough figures from the graph in the cree spec sheet, I get the following

0-20 degrees (40 total): 11% of lumens
0-40 degrees (80 total): 41% of lumens
0-60 degrees (120 total): 77% of lumens

So the edge of the 502's beam, only gets 55% of the intensity that the centre of the beam gets direct from the led unless it is using a lens to adjust this. And 23% of the led's output is hitting the "reflector" (unless there is a lens between the led and the reflector).

If someone wants to check my maths that would be nice. Note I used the following numbers:
 region relative intensity 0-20 96% 20-40 90% 40-60 70% 60-80 35% 80-90 5%

22. Re: ZebraLight H502 XM-L

Guys, please stop it with the mattthhhhhh.

23. Re: ZebraLight H502 XM-L

Originally Posted by psychbeat
yah we need someone to point these little buggers @ a lux meter
Someone must have a lux meter, can we get some real numbers, please?

All of the theorycraft is hurting my head

24. Re: ZebraLight H502 XM-L

Originally Posted by bbb74
To calculate the proportion of lumens coming out at different angles needs a bit of math. Using rough figures from the graph in the cree spec sheet, I get the following

0-20 degrees (40 total): 11% of lumens
0-40 degrees (80 total): 41% of lumens
0-60 degrees (120 total): 77% of lumens
I didn't check the calculations, but these are quite close to the results I was expecting.

Originally Posted by Esko
Originally Posted by YoSeKi
You are probably right. 80% might be a little high. It may be closer to 70%.
Or something like 40-50%.
Originally Posted by Ezeriel
Someone must have a lux meter, can we get some real numbers, please?

All of the theorycraft is hurting my head
You can't measure surface area (total output of lumens) with a lux meter only.

I have a lux meter, and a quick handheld test gave a result that the beam intensity drops to ~50% at the periphery (measured at the same distance - it would drop more on white wall because the distance is not constant).

25. Re: ZebraLight H502 XM-L

Update: 15 days and no reply from zebralight for the h502 i sent for an rma. I think I will never buy one of their lights again

26. Re: ZebraLight H502 XM-L

Originally Posted by Esko
You can't measure surface area (total output of lumens) with a lux meter only.
That's exactly correct so somebody else gets it The maths involves calculating the surface area of a spherical cap or spherical segment and then weighting the surface areas of that segment against the approx relative lux in that segment from the xm-l spec sheet. (Think of a sphere, with the LED in the exact middle pointing straight up. The 0-20 degree "band" forms a cone that intersects the outside of the sphere and creates a cap at the top, and you calculate the surface area of the cap. Then take the 20-40 degree band and do the same etc etc.). The amount of light in each of those bands is related to BOTH the band's surface area, and the relative intensity of the xm-l at those angles.

Anyway, I was using my h502c last night to read with, and I have to admit that when I moved and the edge of the beam ended up on the book, I didn't like the yellowy-greeny edge of the beam which is a shame because the overall tint is fantastic. The coloured band is in the edge of the main beam which includes light coming directly from the led (the led is directly contributing light to the green bit of the beam). ie. The green tinted bit contains light coming from the led and reflector, not just from the reflector only. Yet the reflector is not that bright at that angle so I still don't really get why it happens so visibly.

27. Re: ZebraLight H502 XM-L

Originally Posted by Photonrunner
If you do the math assuming the 502 and 501 evenly distribute there lumens the beam intensity is higher on the 96 lumen 80deg beam than the 260 120deg beam. I don't have the 502 primarily because of this reason. so I can't do a real world comparison. However I run a lot with my 501 and it's sufficient for road running at decent clip 5:30/mi to 6:00/mi If I go on trails I bring something in hand with a little more throw. This is why I would love a 502 80 deg 260 lumen head lamp. Would like more throw to see obstacles further ahead. I haven't tried the 502 due to my scepticism of the 120deg beam, but perhaps I'm wrong and it's sufficient light or better than the 501. Would like to hear a real world comparison for running if someone has the time and both models.
My respond to your fine post was lost. I am responding again.

You use the H501 to run with and wish it was brighter and therefore throw better. You are not alone. I had the H501 and felt the same way. The H502 with 260lm, if made in an 80 degree beam, might have been the answer. Would 260lm in an 80 degree beam provide more throw than 80lm in an 80 degree beam? I would think so.

You post is so clear I think a doorknob would understand. Thank you.

28. Re: ZebraLight H502 XM-L

but if we knew how much lux the light produced at 1 meter we would have a general idea of how dispersed the light is when compared to other lights and even when just looking at the stats, X amount of lux at one meter with a X foot area of coverage.. that's something I can wrap my head around

29. H502c In Practice (Non-theoretical!)

I put my H502c to hard use last night.

A contractor and I are re-roofing my garage, starting with a complete tear-off. Tricky summer weather here, 104 degrees in the day, but thunderstorms can build with little warning. Yesterday I thought I heard thunder around 5 pm, and told the contractor I really, really wanted to get the tar paper on, by the end of the day. So we pushed it hard, and started laying the tar paper around 2 hrs AFTER sunset.

So this is a difficult test for a headlamp: I'm putting on a pitch-black substance which soaks up light like a sponge. But it must be placed with a precise overlap and no bubbles or wrinkles. Due to various obstacles the job took several hours so I needed runtime. And I'm clinging to the side of a 40-degree roof, which wants to pitch me off, so the light is vital to safety as well (seeing where to step, stubbing toe on a shiner, etc.)

The color of the OSB ("plywood") is about the same color as our compressed air hoses, yellow. I was able to make out the subtle difference in color well enough to not step on a line (they'll roll underfoot, and off the roof you go!). There was enough light with enough runtime to complete the job on the Medium (Hi) level, and I probably could have used the Hi (Lo) level but was conserving runtime as I had forgotten to put a spare cell in my pocket. (Dumb.)

There were two or thee times when I "ran out of light" at the edge of the beam--ie, the beam was not quite wide enough!! This required repositioning my body so I could throw the beam where it needed to go...but this was a learning moment about the importance of a full flood for close work. The H502c now replaces the narrower-beamed H501 as my preferred work light, primarily because of its extra beam width.

Verdict: Wide beam, sufficient illumination, good color rendering, no falls, tough job completed. A keeper. Will need to get a spare, likely a "w" for comparison purposes.

30. It seems my last post was lost so here it goes again.
I received my 502c a few days ago. There is an obvious green hue around the outer edge but I can't really see it in real use so it doesn't bother me. I can also see some light leaking through around the switch boot so I guess this means that I got one of the less than water resistant duds. It's going back and I just may wait a few more months for a revision to be released. This is my first true flood light and I'm so excited that I'm not ready to give up on the 502c just yet..

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