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Thread: Dosun Solar Headlamp

  1. #1
    Flashaholic nzbazza's Avatar
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    Default Dosun Solar Headlamp

    Just been browsing through Fenix-Store.com and noticed that they have a new headlamp for sale: the Dosun H-1.

    This headlamp has some really interesting ideas, firstly by twisting the bezel one can go from spot to flood, no flipping flimsy diffusers, and also have a eye-shaped flood as well, and secondly, there is a main beam focussed out to 10m and a second beam aimed 1m out.

    The design engineers seemed to of thought of most things such as heatsinking, battery level indicators, output regulation, waterproofing (IPX?). No word on light output or runtimes on each of 5 levels.

    Details here https://www.fenix-store.com/product_...roducts_id=487

    and the Dosun website is here
    http://www.dosun.us/portablelight/index_light.html

    it has nice pictures of the different beam profiles


    Features
      1. Dosun Bi-Light reflector (patent pending) simultaneously illuminates at one meter and ten meters
      2. Three beam profiles
        • Focused Llight (spot)
        • Eagle Light (cut-off flood)
        • Flood Light (flood)
      3. Five modes of output
        • 1
        • 2
        • 3
        • 4
        • 5
      4. Aluminum heatsink
      5. Battery power gauge
      6. Water proof construction
      7. Digitally regulated constant current
      8. 3AA battery pack
    Is that a torch in your pocket or are you just pleased to see me?

  2. #2

    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    Any review?

  3. #3
    Flashaholic* PhantomPhoton's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    Looks interesting. Too bad I can't see anything on their website because it's all flash trash.
    I agree it looks like they've thought out some important things. Hope to see more detials for this soon.
    1) Neutral white, it's the new black. Heck, it's not even "new" anymore.
    2) User Interface... KISS.
    3) Proprietary cells and battery packs - Just say NO!

  4. #4

    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    Yeah, this does look interesting. Kind of big, but some people don't mind that. 3AA format sounds good.

    I've been wondering when more Cree headlamps would come out. I'm looking forward to a review from someone! (Probably won't be me, I've got a Zebralight H30 in the mail right now, and an SSC U star waiting to plug into my Petzl Tikka XP.)
    Last edited by josiah; 06-13-2008 at 02:53 PM.

  5. #5
    *Flashaholic* Illum's Avatar
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    Duh2 Re: Dosun Solar Headlamp at Fenix-Store.com

    judging from the pics on fenix-store.com, the cree is mounted on a half circular stool and the dome oriented horizontally at the reflector rather than parallel with it

    I'm not sure what kind of beam profile your going to get but its not going to be round. Note also the two different halves of the reflector used

    This lights begging for a beamshot test

    Pics rehosted for argument purposes


    Last edited by Illum; 06-13-2008 at 03:26 PM.

  6. #6
    Flashaholic* half-watt's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    just ordered one to ship via USPS Priority Mail. hope to rcv. it Tues or Wed of next week, depending upon when FS ships it.

    i'll Post back w/any salient info.

  7. #7
    Flashaholic* PhantomPhoton's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    Quote Originally Posted by half-watt View Post
    just ordered one to ship via USPS Priority Mail. hope to rcv. it Tues or Wed of next week, depending upon when FS ships it.

    i'll Post back w/any salient info.
    Thanks, I look forward to your findings!


    I do think the reflector and emitter setup looks interesting. I still think throw/ flood would be better off of a 2-emitter headlamp, but hey if I knew everything...
    1) Neutral white, it's the new black. Heck, it's not even "new" anymore.
    2) User Interface... KISS.
    3) Proprietary cells and battery packs - Just say NO!

  8. #8
    Flashaholic* 276's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    i just want to know the lumen rating of them?
    Surefire,Inova,4Sevens,Fenix,Olight,Malkoff, AEX25,Xeray50,Polarion Aybss Dual, AElight 30-50 watt,Wiseled tactical 2000,Peak, Lupine Wilma TL, .......

  9. #9

    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    I've got one on the way and with luck it will be here tomorrow. If it is at least as bright as my modified PT Apex, has some usable beam patterns, decent run-times, and very durable/water resistant, I'll be thrilled.

    I called Fenix-Store today about it and they were still awaiting a detailed spec sheet, but was told that it "appeared to be a Q5" but they still need the manufacturer's spec sheet to confirm.
    Last edited by Yucca Patrol; 06-13-2008 at 11:37 PM.

  10. #10
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    Interesting design... I can't wait to hear the reviews.
    Looking for: jhanko 'biohazard' V10R Ti clip, Luce de Notte (SS / Ti), SF Z2 (body, complete light, bored, unbored). Pls PM me with an offer.

  11. #11

    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    The beamshots are certainly going to be odd, but perhaps they will be useful. Hopefully my unit will arrive tomorrow.

    I'm just so curious that I had to get one to see what it would do. . . and it will be something to play with until Surefire and Fenix release their models. . . .

  12. #12
    *Flashaholic* Illum's Avatar
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    Smile Re: Dosun Solar Headlamp at Fenix-Store.com

    Quote Originally Posted by Yucca Patrol View Post
    The beamshots are certainly going to be odd, but perhaps they will be useful. Hopefully my unit will arrive tomorrow.
    Not necessarily odd as such design concepts have been previously discussed here on the forum.
    I'm sure many of you are familiar with mcGizmo's Tri-lobe reflector?
    http://www.candlepowerforums.com/vb/...d.php?t=138999
    Well Evan9162 tried the "bi-lobe" concept similar with what Dosun did. Provided the reflector is positioned correctly for optimal focusing I'd say the beamshots looks pretty good
    http://candlepowerforums.com/vb/showthread.php?t=40228

    From the looks of it Dosun simply has one side textured to diffuse the spot beam and the other side faceted for throw, it doesn't appear that the parabolic value between the reflectors change so I'm not sure what difference the throw values would be...

    Just from the standpoint of looking at the pics I could speculate that the heatsink used for the CREE looks pretty solid, I hope theres a bigger chunk worth of aluminum somewhere around back.

    Waiting for reviews

  13. #13

    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    I just received mine this morning, but will have to wait until this evening to post some beamshots and compare it's performance against my modified PT Apex headlamps.

    The battery case seals well with a rubber o-ring and thumbscrew, so it should be waterproof. The buttons are raised and easy to feel, and also appear waterproof and sealed to the unit.

    The back of the lamp is a solid plate of aluminum, so there seems to be adequate heat-sinking.

    It would be nicer if the rotating bezel clicked into place at each of the three different reflectors, but there are some raised ridges to help align the reflectors by feel.

    The various beams are certainly odd, and will look strange against a white wall, but might be very useful in real-world situations, but I'll have to wait until tonight to really get an idea of how they will work.

    The plastic construction seems quite solid and just a little bit flexible which might be better than being brittle.
    Last edited by Yucca Patrol; 06-16-2008 at 12:27 PM.

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    Flashaholic jezzyp's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    We call them torches here in England...

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    Flashaholic* cat's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com




    Compared to the Primus Race that Szemhazai reviewed (Primus PrimeLite Race - review [Rebel inside]), which is about the same price and also has an alloy head, the Dosun has the advantage [?] of the adjustable focus. Some close-up photos of the Dosun would help me choose.

    PS: A big disadvantage of the Dosun is that it has 2 strobe modes.
    Last edited by cat; 06-18-2008 at 05:53 AM.

  16. #16
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    Depending on the precise LED positioning, it's certainly possible to get a more-than-passable spot beam out of a single LED firing into half a reflector, even a reflector designed for a regular bulb. If you don't want a semicircular beam, the LED needs to be positioned slightly off the 'correct' position, and if done correctly, that can give a fairly circular beam except when very close-up

    For a headlight, there's the advantage that if the LED is downward-firing, the light that misses the front of the reflector can give a good downspill of light, as long as the reflector isn't too relatively deep.
    Presumably that's what Dosun refer to as 'Bi-Light'?

    I've been making/selling caving lights using that geometry for the spot beam since mid-2004.

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    Default Re: Dosun Solar Headlamp

    Tri X Bi light would be more appropriate.
    It provides 'two modes': via the reflector (which has three profiles), and straight to the ground.

    http://www.dosun.us/portablelight/im...ame/H1/H-1.gif

    What is with the name 'eagle light'? Because eagles have good stereoscopic vision. It looks very interesting, spot or flood? Yes I will have both.
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  18. #18
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    Quote Originally Posted by MichaelW View Post
    It provides 'two modes': via the reflector (which has three profiles), and straight to the ground.
    If that's the core of the idea that they have a patent pending on, unless they filed for a patent quite some time ago, they may have a bit of a prior-art problem if anyone wanted to challenge them.

    As far as I can see, once there's the basic idea already out there of using a section of a reflector in a headtorch to get a spot beam with good downspill, having a rotating bezel to bring in different reflector profiles is a pretty obvious step (for anyone who wants different beam profiles), not really any more novel than, say, having a rotating bezel allowing a diffuse film to be brought into a beam.

  19. #19
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    Default Re: Dosun Solar Headlamp

    I say you sell them your prior art... Or mention that you will sell the prior art to someone like Maglight. Should be worth a few bucks.
    Why does my wallet cry when I browse this site?

  20. #20
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    Quote Originally Posted by PocketBeam View Post
    I say you sell them your prior art... Or mention that you will sell the prior art to someone like Maglight. Should be worth a few bucks.
    I think with patents, once something is out there in public and unpatented, that's it. It's not novel anymore.
    Anyway, it seems fairly clear that the idea of using a section of a reflector was something that other people were experimenting with at around the same time, quite independently.

  21. #21
    Flashaholic* half-watt's Avatar
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    Default Re: Dosun Solar Headlamp

    1. DoSun's idea may still be patentable - depends upon the "claims" (viz. the proper legal term) that they make. it is not unusual to have a couple of dozen claims in a single patent. an engineer who works for a company might like to break these "claims" out into multiple patents (sometimes successfuly; sometimes not), but often corporate patent counsel will bundle a bunch together, either for legal reasons (to better insure that the patent is granted), or for financial reasons (cheaper to file for one patent than for five patents or two dozen).

    2. DoSun's idea may(???) be unique in certain respects - particularly their "eagle" [eye] beam pattern (broad/wide like our eyes are naturally used to seeing in daylight). some headlamps provide this feature as an array of multiple LEDs (think FoxFury here) and as a somewhat fixed output mode (unless lower output levels are used by lighting fewer LEDs, again FoxFury). DoSun uses a single light source and a moveable reflector such that the wide/broad/eagle beam is not mandatory. also, the output level is variable for any of the beam patterns. is this unique? don't know. one would need to do a search of prior art.

    3. If the next logical step has NOT been patented, then it may(???) be patented subject to at the very least the following standard caveat (using the actual legalese phraseology which after 25+ yrs as an engineer i've now committed to memory): "the invention must be unobvious to one skilled in the art". the comment on the rotating bezel might(???) be obvious to one skilled in the art of headlamp design, but then it might not be so to the patent examiner and so might be granted (though it could later be challenged in court with outcome uncertain). however, IMO, it would not so much be the concept of the rotating bezel, but rather the overall system operation that might be patentable, i.e. something like "a system using [some "tech" [talk/speak], to use the Hollywood script writing term, here for their particular mechanism/design] which rotates between three areas of a reflector, providing a pure flood output, a unique[??? i'm not sure 'bout this either being unique, but assume for the moment that it is] wide angle field of illumination from a single LED light source, and a near-far dual spot...". something like the idea of a four wheeled vehicle that moves under its own power is a nice concept/idea, but is not patentable in and of itself. patents are intended to provide protection and foster an atmosphere of creativity. such a broad claim of a four wheeled vehicle that moves under its own power (i.e. self-propelled) would stifle creativity and would never be granted, IMO.

    4. as far as public knowlegde goes, that would, again, probably depend upon the "claims" made in DoSun's patent. public knowledge and knowledge which the inventor has not kept secret until disclosing and applying for a patent (though the patent may not yet be granted), is not patentable.

    5. in the good ol' USofA patents are good for 17y after which others may make use of one's invention without licensing/royalties (this, again, is to foster continual improvement and invention, hence the shorter "protection" of 17y for US patents), though they are in effect longer in some other countries.

    i've been amazed at what can get patented. for some decades now with a technology explosion occurring and patent examiners not knowledgeable in some areas of science and technology, sometimes patents are granted which would never even pass the test of "unobvious to one skilled in the art". however, the patent examiner grants the patent since he/she is not skilled in the art and thinks that the invention is pretty neat. among others, there is a famous early software patent granted a number of years ago regarding insuring the visibility of a mouse pointer/cursor regardless of the background color. this patent was granted when, IMO, it never should have been due to the innate/obvious method that was being employed (a programmer would obviously use the XOR [aka "logical difference"] operation to ensure pointer visibility on any background color). an entire US company was formed on the basis of the patent with what appeared to be one sole "raison d'etre" [i.e. "reason for being" - IIRC, this company at the time did not have a marketable product - only an obvious idea for which a patent was, IMO, mistakenly granted], viz. with a legal department that cruised trade shows and conventions looking for POSSIBLE patent "infringement" and then issued letters demanding either cease and desist or licensing royalties, else the inevitable litigation would ensue - both Apple and IBM received "nastygrams" from the legal vultures circling above, or is it the bottom-feeding slugs slithering along??
    Last edited by half-watt; 06-19-2008 at 03:33 AM.

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    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    The 'flat' beam is somewhat unusual, though noncircular beams from LEDs do seem to be available in various LED optics, so the possibility of doing something similar with a reflector isn't enirely novel.
    In fact, if playing with an LED and half a reflector, the possibility (if not the actuality) of all kinds of odd shapes is hard to avoid, though it would presumably take some ability with optics and/or good software to get a nice clean beam pattern of given shape.

    I wonder, would some similar effect (spot, diffuse, oval) be possible if using a fixed half-reflector along with a rotating front-glass with a fresnel lens for the oval, as well as a fresnel +/or diffuser film for the diffuse light?

  23. #23
    Flashaholic* lasercrazy's Avatar
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    Default Re: Dosun Solar Headlamp

    So where are the beamshots?
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    Flashaholic* half-watt's Avatar
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    Default Re: Dosun Solar Headlamp at Fenix-Store.com

    Quote Originally Posted by 276 View Post
    i just want to know the lumen rating of them?
    all number Mfr. Claimed:

    Boost 120% / 104 lm for MOMENTARY use (not sure of continuous TIME allowed)
    Hi 100% / 93.6 lm for 3h on alk. (currently testing it with Sanyo 2700 NiMH 02:07 at this time)
    Med 60% / 52 lm for 5h
    Lo 30% / 20.8 lm for 12h
    Slow Strobe (a dbl-flash with a short pause) 100%/Hi for 12h
    Fast Strobe (very fast strobe) 100%/Hi for 6h (so, probably a 50% duty cycle or thereabouts since burn-time is 2x constant 100%/Hi burn-time).

    i'll try to remember to Post-back the final burn-time on Hi w/the Sanyo 2700 (they came off the charger early yesterday evening and the burn-time test started at 0730 today).

    if the burn-time results are similar to another CPF-er's test of the DoSun R1 (a 2xAA flashlight), then the NiMH burn-times in the H1 are expected to be >2x as long as cp. to the alk. burn-times. however, other than the fact that both lights are made by DoSun, there is no other basis on my part for ASSUMING (actually HOPING) that a similar increase in burn-time will occur with the H1 running off of 3xAA NiMH.


    EDIT:
    at this point in time i still don't have a light meter (logging or otherwise) and am merely timing the burn-time until the light becomes very dim, glows, or shuts off (don't know if direct drive occurs if Vin gets too low to support the regulator/converter electronics).

    also, have never owned a camera, so no beamshots from me. beamshots, IMO, would NOT be helpful unless they were pics of actual outdoor use. why? the reflector on the H1 has three distinct areas which are rotated to the bottom of the head, thus placing that portion of the reflector directly UNDER the downward firing LED (the LED has a reflective cylinder all around it, including "out the front", except the part pointing down which allows light to only directly strike the bottom ~120deg of the reflector when the reflector is positioned at any azimuth.

    if one is white wall "hunting", the beam is NOT a pretty beam, IMO, when in any of the three positions (i.e. spot, eagle [a broad/wide horizontal beam pattern], or flood). however, in actual use the artifact-like anomalies in the beam's appearance are *NOT* at all objectionable. anyone who is used to a good incandescent/Xenon headlamp beam probably won't mind the beam patterns of the H1 at all. IMO, while NOT up to LED beam pattern standards (ignore Cree-donuts and rings), it is better than Xenon headlamp beams that i've used, or at the very least as good as some of the better Xenon headlamp beams in terms of appearance and artifacts.

    only other point of note at this time is that while a "Herculean" effort is *NOT* required to actuate the buttons (two of them to be precise - ON/OFF/MODE selection button w/a 2sec press and hold to turn OFF, and a BOOST button), the buttons, IMO, required just a tad too much force to actuate - though this can probably prevent accidental "turn-on" in one's pack.
    Last edited by half-watt; 06-19-2008 at 07:51 AM.

  25. #25
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    So where are the beamshots?
    They do at least have illuminance maps on the Dosun site.
    I guess it's hard to do a good beamshot of both parts of the beam in operation, hence their drawings.

    (PS another possibly useful feature of the downfiring-into-partial-reflector geometry is that as well as giving good downspill, there's very little upspill above the spot, which means it's a very nice non-dazzling arrangement if looking at someone wearing one, as long as they're directing the spot at or below your chin.)

  26. #26
    Flashaholic* half-watt's Avatar
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    Default Re: Dosun Solar Headlamp

    Quote Originally Posted by uk_caver View Post
    another possibly useful feature of the downfiring-into-partial-reflector geometry is that as well as giving good downspill, there's very little upspill above the spot, which means it's a very nice non-dazzling arrangement if looking at someone wearing one, as long as they're directing the spot at or below your chin.)
    EXCELLENT POINT!! wish i had mentioned it in a Post. good observation on your part. i noticed the sharp cut-off (almost like in some auto HID headlights) in the "eagle" beam pattern, but failed to really take notice of it in the "spot" (other than the fact that the "spot" is somewhat well defined, but still with decent spill).

  27. #27
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    I can't see any real value in a boost that's only seemingly ~10% higher than the regular Hi output level, beyond allowing the packaging/marketing to carry a number above 100 lumens despite any given lamp hardly ever (possibly never) being likely to be run at that level.
    Practically speaking, it seems likely to be almost totally pointless.

  28. #28
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    The lack of upspill is most easily noticeable when *other* people are using lights in a face-to-face group situation.
    Otherwise, except maybe if using a light for crawling or climbing, you may well not notice that feature of the beam.
    However, even face-to-face, it's easy to simply not notice being dazzled, rather than to notice not being dazzled.

  29. #29
    Flashaholic* half-watt's Avatar
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    Default Re: Dosun Solar Headlamp

    Quote Originally Posted by uk_caver View Post
    I can't see any real value in a boost that's only seemingly ~10% higher than the regular Hi output level, beyond allowing the packaging/marketing to carry a number above 100 lumens despite any given lamp hardly ever (possibly never) being likely to be run at that level...
    another excellent point. DoSun's claim of 120% figure output for their BOOST increase over HI/100% output differ's from their actual "claimed" lumen numbers (104 v. 93.6) which have the "Boost" only ~11% higher.

    however, indoors, an increase "Boosted" output is noticeable to the "eye" (not sure what a light meter would show - that would be interesting), and i get the impression that it's at least 33% (or a bit more) brighter. i only say this b/c some years ago, while playing with a Photon Fusion headlamp, i learned that 33% is 'bout the smallest increase in light output that i can easily notice w/o having to switch back-and-forth b/t modes multiple times to make sure that i'm really perceiving (and not imagining) an increase in light output.

    again, it's daylight here, and my darkened basement is my only testing "grounds", so to speak, at this point in time. indoors in the basement the BOOST difference is easily noticeable both on white wall and the basement workshop which doesn't have any white walls - just studs, wood, concrete, tools, and equipment, etc.. don't know, however, if BOOST will be noticeable out in the forest on a hike or in camp at night; probably not much or at all if it's really only a 10% to 20% increase in brightness. not a caver, so i won't speculate at all in its use for caving (it's probably *NOT* robust enough in construction, but then again, the Petzl Duo is of plastic construction and is used for caving, by some cavers at least - ok, ok,...so, i speculated...).


    EDIT:

    HI/100% burn-time test is at ~03:28 on 3xAA Sanyo 2700 NiMH.

    while extremely imprecise, to say the least, the H1 output still appears to be as bright as when i started. however, i'd be kidding myself if i asserted that the light output appears the same to my eye now as when i started the "test" (i almost hesitate to call it a "test"). how am i to really know if less Lux is being output without a light meter? all i'm saying is that it is still quite bright and i can't tell if it has dimmed any.

    also, DoSun warns NOT to touch the aluminum backplate on the head as it can get rather hot when used for a period of time on the higher output mode(s).

    don't know if it the reduced voltage (i.e., as cp. to alk. cells) of the NiMH cells is the reason, but the Al backplate has never really gotten too hot to touch, just quite warm or slightly hot (could hold my fingertips there for several seconds with no problem; removed them NOT b/c of heat). checking now, maybe light output is down a bit as the Al backplate, while still very warm, seems to me to be just a bit cooler than when i started and the cell voltage was higher. just held my fingertips there for 10s and there is no doubt that i would NOT have to remove them due to heat even one or two minutes later (or longer).
    Last edited by half-watt; 06-19-2008 at 08:54 AM.

  30. #30
    Flashaholic* uk_caver's Avatar
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    Default Re: Dosun Solar Headlamp

    I'd certainly agree with you that something like a 30% brightness difference is about the smallest that might be reliably detected by eye with even the briefest interruption while changing power levels.

    What happens as the cells discharge - does it switch levels, slowly fade, or suck the cells dry?

    Heatsink-wise, unless there was a large mass of aluminium acting as a thermal store, I'd guess that with only a Watt or so of heat going in, if you could hold your fingers on the heatsink for more than a few seconds without pain, you could probably hold them there indefinitely.

    (Underground, Duos actually seem to do fairly well, though they are designed to be easily boltable onto helmets, not relying on elastic straps like most other lamps. However, unlike most headtorches, they are designed by a company that was started by a serious caver, and which is a major supplier of caving hardware.)

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