Wuben        
Page 3 of 5 FirstFirst 12345 LastLast
Results 61 to 90 of 149

Thread: Replacement of carbide lamps by LED lamps

  1. #61
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Tobias Bossert View Post
    You are completely right, homemade optimum and industrially produced optimum are different!
    Now I can not avoid to think from a industrial point of view...



    It's only 6 positions, same as me too!
    It seems that is more or lees the number of scenarios we can find when caving.

    The 90lm is very demanding. XR-E R2 is >114lm@350mA and you will lose some % of light internally too. Flood is o.k. but with the optic lens it would be rather 70...80lm.
    As far as I see, XR-E R2 at the present is availlable in color WG only, too greenish. WC or WD would be more nice, but these are Q5 only.
    I would not use a optic with a CREE for flood. They are excelent as they come for that purpose.

    70h, 7h, 3.5h, 1.5h, 1.5h
    You are right, it was a typo. What do you think about those runtimes on a battery integrated device?

    I'm verry eager to see whether you can solve these demanding technical problems!
    According to my first calculations it could be done on something like a prism with the following dimensions:

    30x40x90mm if it has integrated battery.Smaller with wire configuration.

    There is another problem I'm still looking for a better solution:
    Surion has a bare P4 which glares very strongly. There will be no improvement with respect to glaring when using a XR-E.
    I tried to avoid glaring by a combination of LED, wideangle reflector and diffuser lens. It does the job verry well but at the expense of at least 30% light loss.
    Glare is not so bad if not aimed directly to your eyes, so my suggestion is just to paint with black marker or black paint the portion on the lense edge that will produce the glare you want to avoid.

    The problem is, that all known diffusers work well as long as the light passes nearely orthogonally. With large incident angles the losses increase dramatically. For this task I would need domed glass front lens (18mm diameter, 4,5...5,5mm hight depending on glass thickness 1...2mm). If I would get those, I can edge or sand them at the concave side by myself. This would decrease the losses and improve the flood tremendously.
    I don't like diffusers either, I think they waste too much light unless you want a very slight diffusion.

    I can send you a dome 20-25 mm (ID-=D) for your homemade lamps if you want to.

    Regards,

    Javier

  2. #62
    Flashaholic Tobias Bossert's Avatar
    Join Date
    Oct 2007
    Location
    Germany, Munich
    Posts
    145

    Default Re: Replacement of carbide lamps by LED lamps

    Hi Javier,
    thanks for your input. The discussion starts now to produce the outcome I hoped for.

    Quote Originally Posted by Barbarin View Post
    I would not use a optic with a CREE for flood. They are excelent as they come for that purpose.
    Yes, you are right, Cree XR-E has its own internal lens just giving the optimum pattern for this typ of flood we need for worklight! It's about twice as strong as SSC P4 on axis and avoids the "useless spill" outside of +/-45°. From this point of view we don't need any further optics for it - from this point of view...

    Glare is not so bad if not aimed directly to your eyes, so my suggestion is just to paint with black marker or black paint the portion on the lense edge that will produce the glare you want to avoid.
    Excuse my limited English, I think my remark on glaring was not understanable. Glaring yourself is not my problem, this can be solved easily as you said by covering the glaring edge of the front lens with black paint.
    Scurion uses SSC P4 behind a plane front lens. The case limits the flood to about +/-70°. So it is unrealistic to avoid glaring your friends by turning your head away when talking with them. Most cavers are of the opinion that this as a big disadvantage of Scurion.
    When we use Cree XR-E for flood part of worklight instead, we reduce the problem only slightly, because the angle is still +/-50%.
    This is the reason I prefere to enlarge the light source area which can be seen from others. My solution outputs the light from an area larger than 100mm², this does not glar the friends anymore.

    I don't like diffusers either, I think they waste too much light unless you want a very slight diffusion.
    Me too, but they are not as bad when used with light inclining the sanded or etched surface rectangular. With my experience it is achievable to reduce the losses below 10% with that. I'm willing to accept additional 10% of loss to avoid glaring my friends.
    With my actual test device I use a plane diffusor, which produce a lot of loss (about 30%) because the inclination angle goes from -45° to +45°. With a spherically domed diffuser (die of XR-E in the center), allmost all light would incline the surface nearely rectangular - and the pattern would be improved additionally!

    I found now domed mineral glass for watches with reasonable diameters. Propably these will be too thin and fragile for a caving headamp, but they are good for experiments to study the losses. I hope I can post my results for that in about two weeks. If it holds true and the losses could be reduced accordingly, it's up to you (or whoever will produce such caving lights) to find a robust domed diffusor front lens.

    Thank you, Javier, for the good idea to combine flood and throw with variable power ratio. With this idea, I will try to develop my 4-LED solution further into a 3-LED solution.
    All three, the focal part of my work light, the light for huge halls and the shaft-spot in my 4-LED solution are on axis. The focal part of work light and the light for huge halls could be realised with only one device when adding an variable portion of the focused shaft-spot.
    Only the diffuse part of the work light is off axis or asymmetric. This I will keep mechanically separate for home made devices, because it is very difficult to realize separately declineable parts of the headlamp.

    It will be no problem to find adequate power ratios and to realize them electronically.

    According to my first calculations it could be done on something like a prism with the following dimensions: 30x40x90mm if it has integrated battery.
    Oh yes, verry compact for a robust headlamp including the battery and providing optimized beams!

    Smaller with wire configuration.
    Since there are many cavers prefering as less weight at the helmet as possible, this variant will find its users too...

    Regards,
    Tobias
    Last edited by Tobias Bossert; 01-02-2009 at 08:22 AM. Reason: had one quote twice

  3. #63
    Flashaholic Tobias Bossert's Avatar
    Join Date
    Oct 2007
    Location
    Germany, Munich
    Posts
    145

    Default Re: Replacement of carbide lamps by LED lamps

    Hi Javier,
    I come back to your proposals in post #56 and #57, because they seem to be good ideas.

    Quote Originally Posted by Barbarin View Post
    I've been playing for a while with “zoomable” optics. The problem with those is that at least the ones I have been testing are "pure spot" beams in which you just have the option to choose the angle of the spot, but it is not a beam with a combined spot and corona.
    I think this is achievable with pure lens optic only. I also experimented a lot with spherical and aspherical lenses.
    For my experience using a single lens, SSC P4 gives nice beam flatness especially with large beam angles. But the losses (side emitted light not catched by the lens) are high and increase when narrowing the beam. You therefore need a "thick" lens with high aperture and with that aberration and internal scattering arrise.
    With Cree XR-E the aperture is not so critical, but the beam flatness is poor (sometimes donut) and color tends to separate concentrically.

    Your pictures look very nice! Propably you have better lenses than me. What are the smalest (pic 1) and largest (pic 4) FWHM angles you achieved with your zoomable optic?

    In case the spreed of angles is huge enough (e.g. 6...60°), we really can think about to use only two light sources and combine them with variing levels (Javier approach):

    Light A is a pure flood with XRE-like pattern (but not glaring the friends) internally mounted with fixed tilt downwards by about 25...35° with respect to the case.

    Light B is a pure zoomable spot without spill internally mounted horizontal with respect to the case.

    The tilt of the whole case must be adjustable of course.

    1) Off
    2) Pauselight: . . . . . . . .Light A (20mA)
    3) Worklight low: . . . . . Light A (80mA)
    4) Worklight medium: . Light A (80mA) + Light B (25mA)*
    5) Worklight high: . . . . .Light A (320mA) + Light B (100mA)*
    6) Short term light: . . . . Light B (1000mA, )
    max focus => shaft-spot
    any angle you like
    max spreed => hall-light

    *) The optimum power ratio using a sharp beam to lighten the upper portion of the flood is to be studied first. I'm not shure, whether it is acceptable to have a sharp edge for long time usage. The throw portion must not be too high. The combination I tested so far (spot was XR-E & Carclo 10201), the optimum ratio was about 3 + 1.
    During worklight you can focus light B as you like (normally 15...30°)

    This lamp needs professional manufacturing, I'm unable to do the mechanics.
    __________________________________________________ __________________

    So hand made lamps should go with fix focus lens optic plus one additional TIR with medium or wide beam and spill, as described in my last post:

    Light A is a pure flood with XRE-like pattern (but not glaring the friends) internally mounted with fixed tilt downwards by about 25...35° with respect to the case.

    Light B is a pure fix focus lens spot without spill internally mounted horizontal with respect to the case.

    Light C is a TIR with about 15...25° and spill internally mounted horizontal with respect to the case.

    The tilt of the whole case must be adjustable of course.

    1) Off
    2) Pauselight: . . . . . . . Light A (20mA)
    3) Worklight low: . . . . .Light A (80mA)
    4) Worklight high: . . . .Light A (320mA) + Light C (100mA)
    5) Shaft-spot: . . . . . . . Light B (1000mA)
    6) Hall-light: . . . . . . . . .Light C (1000mA) + Light B (320mA)

    In case we use MC-E & Carclo 10195 (FWHM ~30°) we can increase position 6) to:

    6) Hall-light: . . . . . . . . .Light C (3000mA) + Light B (1000mA)

    Regards
    Tobias

  4. #64
    Flashaholic Tobias Bossert's Avatar
    Join Date
    Oct 2007
    Location
    Germany, Munich
    Posts
    145

    Default Re: Replacement of carbide lamps by LED lamps

    Firts report from real life test in a large cave

    Test report for test device_2
    Predefined questions;
    report/answers of tester (‘Bucherl’);
    remarks/conclusions of developer (‘Tobias’)
    Test environment?
    Four days cave expedition (27. to 30.12.2008) in ‘Tiefkarkluft’ of ‘Hirlatzhöhle’ (Austria)
    Situations encountered?
    Fast walking over very long distances; crawling; climbing; cave surveying; rests; bivouac

    1) Pause-light
    Is the pause-light strong enough?

    The pause-light of test-device_2 was the only thing which I couldn’t use! It is medium beam and oriented horizontally – impossible to give a look into your backpack and even impossible to see what’s in your food basket. The pause light must be tilt downwards like the diffuse-light in the work-light. It wasn’t possible to decline down my helmet mount (which allows tilting) enough to overcome this problem: inacceptable!

    Should the beam be narrower or wider?
    Can’t say this by testing – only suppose it: should be wider. I propose to use the diffuse-light in a further dimmed stage as pause-light.
    O.K., I will switch pause-light to diffuse-light in test-device_3!

    2) Work-light
    2a) Absolute intensity
    Is the work-light low even too strong for crawling and climbing?

    For crawling it is very bright (could be much darker), but also during crawling I sometimes have to look in which direction could be a prolongation. So it doesn’t matter really, that it is very bright during crawling.
    Not only the dimension of the room is of interest, but even more the reflectivity of the materials surrounding you. It’s a reasonable compromise.


    Is the work-light high strong enough for fast walking on dark ground?
    Yes, it is – even if you really “run down” an uneven slope. Camparable to Scurion in its highest setting (bare P4 at 1000 mA)! When you go immediately behind someone with a medium Scurion setting, he gets problems with his own shadows.

    Does the power ratio between work-light low and high should be smaller or larger?
    There seems to be no general answer to this question. It depends upon so many things like power consumption (runtime), your own physiological condition and the situation in the cave. The difference is reasonable at least. The Scurion developers seem to have taken this into account and made the switchable levels programmable.
    My proposal is 1:2 and a third work-light additionally below ‘low’ (about 50% of low) and without ‘light-up’, which will be useful for climbing, crawling and pauses too. And if you have to save energy for some reason, you even can walk with that.

    Conclusion for test-device3 (LED currents):

    . . . . . . . . | . . .light-up. . .|. .diffuse-light . |
    . . . . . . . . |device_2. .
    device_3|device_2. .device_3|

    pause-light . . |. 15 mA. . .--- mA | --- mA . . .50 mA |
    work-light low. |. 40 mA. . . 30 mA | 135 mA . . 150 mA |
    work-light high |. 90 mA. . .125 mA | 295 mA . . 250 mA |

    Device_3 pause-light will have an overall output three times higher than device_2. Because the new pause-light will be much wider, the intensity will not be brighter than in the centre of the old one. The Candella values inside the beam (FWHM 90°) will be comparable to the on-axis values of a plane SSC P4 driven with 100mA and thus be sufficient for crawling and slow walking (in absence of other strong lights).
    Work-light low will have a slightly reduced part of light-up (for light-up device_2 uses 1/4 of the overall consumption, device_3 will use about 1/6 only).
    Work-light high will have a slightly increased part of light-up (for light-up device_2 uses 1/4 of the overall consumption, device_3 will use about 1/3).
    For light-up device_2 uses a single chip LED (XR-E) in Carclo 20mm TIR frosted medium (#10211) with FWHM of 20°. Device_3 will use a four chip LED (MC-E) in Carclo 20mm TIR frosted narrow (#10194) or frosted medium (#10195) with FWHM of 24° or 28°. The reason is that we can do without an additional “flood 40° for huge halls”. Which TIR will be used at the end depends upon the beam of the optic: I must have a try first!

    2b) Relative intensity
    Does the light-up should be stronger or weeker?
    It’s the same as above: there is no general answer – it depends. In small parts of the cave the light-up tends to be too strong, in large parts it could be even stronger too. I propose not to change it, it’s a reasonable compromise.
    It makes also a big difference whether you go up or down a slope. For going up you could do without any light-up, but going down its very helpful.
    The light-up is very useful during surveying: The diffuse-light is strong enough for the paper to write on it and the light-up enables you to see the contours of the room too.

    See clause 2a. I will not make changes in principle but slightly optimize towards:
    - pause-light is also for crawling and passing very narrow parts and serves as emergency light too
    - work-light low is for small and medium parts and/or ascending
    - work-light high is for medium and large parts and/or descending

    2c) Diffuse-light
    The diffuse-light of device_2 has a FWHM of about 90° and a slowly decreasing spill up to FW of 110°. The device_1 you saw in Obertraun meeting had a FWHM of about 80° and quickly decreasing spill up to FW of 90°.
    Could I reduce the FWHM and the spill (this would increase brightness inside the beam)?
    The diffuse-light is good as it is. It must not be wider. May be it could be a little bit narrower (10°?) but it is really desirable to have this very soft “edge” which you do not see during long term usage.
    I leave the diffuse light as it is – with sleight improvements: Device_2 uses a self etched plane glass lens, which produces much losses far off-axis. Device_3 will use a spherically domed self etched glass lens. With this the “beam” will seem to be wider and flatter when using the same reflector. I compensate this modifying the reflector. So at the end the shape will be similar, but a little bit brighter.
    The intensity of etching controls the “width of the beam” and also the amount of antiglare effect.

    2d) Light-up
    Device_2 has a light-up with FWHM of 20° with relatively wide and smooth spill (frosted). That one from device_1 you saw at Obertraun meeting had a FWHM of 16° and less dispersed spill (rippled).
    Should the light-up be narrower or wider?
    It’s similar to the the intensity of light-up: for short distances it could be wider and for large distances it could be narrower. Do’nt change it strongly, it’s reasonable.

    Should the light up have more or less spill?

    The smoother transition between light-up and diffuse-light is much better than the somewhat abrupt one of device_1. Don’t go back to rippled.
    We tried to find a combination of flood and throw with Scurion (as recommended by the manufacturer), but for long term usage the spot was annoying and both use go without spot al the time (that means, they use spot transiently in case of watching a huge hall, a long tunnel or a shaft only).

    I will try not to change the pattern as it is. But I have to make it a little bit wider (even smaller than “frosted wide”) because device_3 will use a four chip LED. I will do my very best...

    2e) Glaring
    What’s about glaring of persons face to face? Need we further suppression of glaring?
    The glaring is much lower than with Scurion – even comparable to conventional carbide lamp. No further development seems to be necessary.
    O.K., with the domed front lenses it will get even better too.

    3) Shaft-light
    Device_1 had a Gaggione Mobdar with SSC P4, delivering a quite similar throw to Scurion (Gaggione LL3 with SSC P4). Additionally I demonstrated a separate thrower Carclo 60mm (#10144) with Luxeon K2 TFFC. You decided, that the extreme thrower would be nice – but it is far away to big to be used in a helmet headlamp. Device_2 now has a bare optical glass lens and the beam is between both systems shown in Obertraun.
    Should the spot be narrower or wider now?
    In any case not narrower! I can’t say whether it should be wider or not without testing it.
    Scurion has a wider beam (may be about double as wide and somewhat more “soft”). It depends upon the situation whichever is better. To watch a huge hall Surion is better than our narrow beam, but for this task we already have our hall-light which surpasses Scurion by far! For narrow pits, shafts or even huge cleft-rooms our thrower is better.
    The shaft-light of device_2 is a single optical glass lens. The beam angle depends on the distance between LED and lens. Device_2 provides FWHM of about 4,3° (80cm Ø in 10m distance). It can be changed to nearly any other angle as desired. With the lens I used (AncorOptics AX 77183) the beam is restricted to about 2m Ø in 10m distance, beyond that arise a week donut. The final decision upon the angle can be taken during mounting the device. The maximum on-axis brightness is reached at about 140cm Ø in 10m distance, astonishingly not with the narrowest beam. Device_3 will provide this adjustment.

    Device_2 provides nearly no spill. Would it be desirable to get some spill (less is impossible)?
    No, please no spill at all for the shaft-light.
    I will not change it!

    Does the sharp and coloured edge of the beam annoy?
    The sharp edge of the beam is quite good for our applications.
    Additionally to looking into deep pits you can assist a climber without glaring him!

    I will not change it!

    4) Hall-light
    It’s unchanged since Obertraun meeting.
    Is the beam sufficiently smooth (there is a week donut visible on white walls)?
    The beam seemed smooth when using it in the cave. Don’t change.

    Could I make the beam a bit wider (and darker in the centre accordingly; this may reduce the size of the reflector)?
    The beam is good, don’t change it.
    Device_3 will come without the separate hall-light of device_2. The compensation of that will be the improved light-up, which will allow up to 700lm now, the separate hall-light of device_2 allowed up t0 900lm. The pattern will be a bit different but even much better than all Scurion can provide too!

    5) Consumption
    How many battery packs did you needed for this four days?
    I took four some years old packs with me, each consisting of 6 NiMH cells with 2000mAh.
    I used the capacity of a bit more than 2 packs only.
    Pack 1: about 19h work-light low and additionally many transient uses of work-light high, hall-light and shaft-light.
    Pack 2: about 13h work-light low, 2h work-light high and additionally many transient uses of hall-light and shaft-light.
    Pack 3: inserted half an hour before leaving the cave, so it’s still nearly unused.


    How many Ah and/or Wh you used?
    About 4.2Ah at nominal 7.2V, that’s about 30Wh.
    The power consumption of the device itself will not change. But realize that you used a test device and didn’t know at the beginning, whether your battery packs will be sufficient. When you are used this lamp, may be you will use work-light high more often.

    How many battery packs used the Scurion users.
    Each of them had two packs, each consisting of 4 LiIon cells with 2600mAh.
    Johann was using its Scurion very restrictively and arrived daylight with its first pack.
    The fist pack of Clemens holds three of four days. When he changed the pack, he was astonished that the second one didn’t work though it was charged freshly. But he had luck, because Johan could give him his second pack.

    As a rough assumption we can say, that Johann used less than 38Wh and Clemens used about 50Wh.

    6) Summary

    1. This pause-light is unsuitable and should be improved. Yes, this will be done
    2. The concept of tilt diffuse-light and smooth horizontal light-up is optimal. Remains unchanged
    3. The shaft-light is very good. Remains unchanged. The beam angle can be chosen during production
    4. The hall-light is impressive, I additionally used it for open day in Koppenbrüllerhöhle. It’s much brighter than the fixed halogen lamp installation.
      It’s really nice to have – but it’s luxury and not ‘must have’ for strenuous expeditions. You can use it for video and photo captures and for guided tours too.
      In case we could simplify the headlamp by this (smaller, less weight and costs), leave it away.

      O.K., this is the reason why I switch now to a three LED approach! There is still a hall-light in device_3, but it uses no longer separate hardware.

    Without the separate hardware for the hall-light the components must not reside so “condensed” in the case. This simplifies the mounting of hand made devices.
    All cavers having seen this test device_2 so far – even those who already bought a Scurion - would like to have a lamp with such features. But I’m unable to produce such things by hand (it would take me about two working days to build each in my cellar), so we should look for someone now being able to produce a small amount of copies of test device_3.

    But first test device_3 must be finished! So work is going on...

  5. #65
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Thank you for your extensive report!

    Regarding the pause-light, why cant you use the work light as pause light? If you tilt the pause light downward they will probably have about the same angle, so all you need is to adjust the output by adding another resistor (and diode).

    You would then have space for the hall light The MC-E works very well with the 22mm BOOM reflectors from ledil. As you only is going to use it on full you may save some space by wiring it in serial and using a step-up driver like the Shark.
    Maybe you already have thought of something like this as you write:
    Quote Originally Posted by Tobias Bossert View Post
    Device_3 will come without the separate hall-light of device_2. The compensation of that will be the improved light-up, which will allow up to 700lm now, the separate hall-light of device_2 allowed up t0 900lm. The pattern will be a bit different but even much better than all Scurion can provide too!
    I dont understand how you will achieve this without separate hardware for getting such high output, but you seem to have something in mind.

    One fantastic thing with the leds is the ability choose very low levels AND very high.
    I was hoping to use two MC-Es, one flood and one spot, and use the flood at highest level for hall-light, but it seems impossible to get satisfying beams with the MC-E.
    Last edited by gillestugan; 01-04-2009 at 02:55 PM. Reason: quote got messed up somehow

  6. #66
    Flashaholic Tobias Bossert's Avatar
    Join Date
    Oct 2007
    Location
    Germany, Munich
    Posts
    145

    Default Re: Replacement of carbide lamps by LED lamps

    Hi Gille,
    I think I should clarify some words I have used.
    There are 4 light sources in the headlamp as shown in the picture:


    One of them - diffuse-light - is tilt downwards. Three of them are not tilt, they are mounted horizontal to the case: shaft-light, light-up and hall-light.
    Shaft-light (XR-E and optical lens) is used alone in switch position 5.
    Hall-light (SSC P7, OP reflector and diffuser frontlens) is used allone in position 6.
    Light-up (XR-E and Carclo 10201) is used in three different switch positions:
    in switch position 2 alone as pause-light
    in switch position 3 together with diffuse-light as work-light low
    in switch position 4 together with diffuse-light as work-light high
    Diffuse-light is never used alone in test device_2, it's always used together with light-up as work-light.

    This means I can tilt downwards the whole case only, because all four lights in it are fixed with respect to the case. I cannot preset the light-up with any tilt, because than it will no more do its job for worklight: its job is to lighten up the upper area of the wide beam of diffuse-light).

    Quote Originally Posted by gillestugan View Post
    Regarding the pause-light, why cant you use the work light as pause light? If you tilt the pause light downward they will probably have about the same angle, so all you need is to adjust the output by adding another resistor (and diode).
    I plan now just to swap the usage in the switch position 2 (pause-light) to use the diffuse-light alone rather than the light-up allone.

    Because the beam patterns of light-up and hall-light are not to much different and the strong hall-light anyhow is luxury, I plan to use the light-up allone additionally as hall-light too. Naturally light-up isn't optimized for this additional task, but I think it will work satisfyingly. With MC-E instead of XR-E in the new version of light-up I need another optic naturally, e.g. Carclo 10194 or 10195. If both donot work well, I will try the BOOM reflectors from Ledil.

    As you only is going to use it on full you may save some space by wiring it in serial and using a step-up driver like the Shark.
    Good idea, thank you, I will think about!

    Regards
    Tobias

  7. #67
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps

    I'm having now a few days vacations, but just received some pictures testing zoom optics on caving. I asked my friends to test no optics + optics at the same time, but it was not possible.

    As the pictures and testing are very related to Barbolight products I have posted the results on a differente thread, but you may find it interesting as they come to explain better the approach of caving headlamp with this capability.

    Javier

  8. #68
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Sorry, I forgot it was in use in your two-beam worklight setup...
    Sounds like a great idea to swap the usage in the switch position.
    Regarding the MC-E optics I would not recommend the 10194 as it has a bad dark cross. It is even worse in real life than in carclos beamshot.
    The 10195 is smoothest of the carclo 20mm optics, I like it, but it is very wide. Hotspot is about 25 degrees with a 30 degree corona. You can find a wall beamshot taken from 2,2m in this thread.
    Beamshots of Boom can be found in the same thread and also in this massive test by IFOR at MTBR.

    What shematics program did you use? I started drawing in LTspice but couldn't find any rotary switches in the component library.

    That cable looks nice. Is it silicone insulated? Oh how nice cables makes me drool

  9. #69
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps

    Well, it is time to work again on this project, after some vacation time.

    Tobias, do you want me to send you some optics?

    I'm sure if you try them that you will agree with the idea of the two LED caving headlamp.

    Regarding the electronics it is not difficult to make a custom drive, but we should reach a quantity to get it at reasonable prices. I'm decided to start this project not as a Barbolight one, but as personal with the CPF'ers who are interested on it, so if we can have a starting point regarding settings, numbre of LEDs, and some basics, that would help a lot.

    Regards,

    Javier

  10. #70
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Javier, your zoom optics seems very nice, but are they small enough? From your pictures of the U-04 ZOOM it seems to be quite large.

    If small and light enough I believe it would work perfect in a 2 led setup. (I prefer ultrawide without hotspot, so 2 leds setup is fine.)

    Have you tried it with a MC-E or P7? probably not working, but i have to ask. Higher output would make the lamp more versalite and you would be able to sell it to many others than cavers. It would for example be great as a helmet lamp, bikelight or orienteering lamp. The ability to zoom would make it far superior to almost any high-end headlamp on the market, for example the €400 Petzl Ultra, the Silva Alpha or the Mila Nova.

  11. #71
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by gillestugan View Post
    Javier, your zoom optics seems very nice, but are they small enough? From your pictures of the U-04 ZOOM it seems to be quite large.
    Hello Gillestugan. Is not that big, just 29 mm.

    If small and light enough I believe it would work perfect in a 2 led setup. (I prefer ultrawide without hotspot, so 2 leds setup is fine.)
    I'm sure we can get everything we need with just two LEDs.

    Have you tried it with a MC-E or P7? probably not working, but i have to ask. Higher output would make the lamp more versalite and you would be able to sell it to many others than cavers. It would for example be great as a helmet lamp, bikelight or orienteering lamp. The ability to zoom would make it far superior to almost any high-end headlamp on the market, for example the €400 Petzl Ultra, the Silva Alpha or the Mila Nova.
    Tried, and yes, it doesn't work. It produces an awfull "window". Not very good job collimating neither spreading. Definetively not quad chip freindly.

    Looking at the picture I posted last day you really think we need more than two LEDs? We had more than enough to beat a 40mm carbide flame, so keeping things within a reason, I think two LEDs at 700 mA each one would be more than enough for 99,5% of the situations.. and it makes no sense having weight, complexity and cost in your head for 0,5% of the situations, while you can carry a handheld flashlight for that moments.

    I'm not thinking on this project as "Barbolight" but as "Barbarin" so by now I want to keep it away from business side. If we go for it it will be this way, more like a modding project. Meanwhile it will be more than interesting to keep on talking here about what we cavers do really need.

    Javier

  12. #72
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps



    I made this simple drawing to show you more graphically this concept of "beam pattern selectable headlight"

    Hope you like it.

    Javier

  13. #73
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    You are right, sorry for going off topic. 2X3W is definitely enough for caving. Especially for caving here in Sweden, haha.

    29mm sounds great. Too small is not good as it probably would be hard to adjust focus with gloves on.

    Khatod has some ultrawide optics that looks good on the paper. The 21mm 70 degree KEPL120908 and the 8.5mm 60 degree PL111806. I will try to get them to try them out. Both are very shallow and would not take much space inside the housing.

    Im not too happy with the performance of a bare XR-E. Colour uniformity is not so good when driven at low levels. The WG tinted I have for testing gets very green/brownish to the sides and bluish in the middle. This gets better when driven att high level.
    The problem can be avoided by using PWM regulation, but then I need a driver with custom programmed levels and I have no knowledge in how to program the pics common on cheap PWM controlled drivers.

  14. #74
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by gillestugan View Post
    You are right, sorry for going off topic. 2X3W is definitely enough for caving. Especially for caving here in Sweden, haha.


    Not so off-topic. I sincerely think that any headlamp wiith 200-300 lm is enough for most activities, not just caving. Of course we all would like the ouput and runtime of the sun, with the size of a nut.

    29mm sounds great. Too small is not good as it probably would be hard to adjust focus with gloves on.


    At the end if you consider the housing and the o-rings it will be like 40 mm OD.

    Khatod has some ultrawide optics that looks good on the paper. The 21mm 70 degree KEPL120908 and the 8.5mm 60 degree PL111806. I will try to get them to try them out. Both are very shallow and would not take much space inside the housing.
    According to my testings any beam narrower than 110º is less than confortable atthe end of some hours, as it will force your neck.

    Im not too happy with the performance of a bare XR-E. Colour uniformity is not so good when driven at low levels. The WG tinted I have for testing gets very green/brownish to the sides and bluish in the middle. This gets better when driven att high level.
    I agree, but from a realistic point of view those are "taxes" we are going to pay anyway. I mean that unfortunately as long as the technology is by now what it is -and I think is amazing compared to just three years ago- a CREE with no optics is one of the best things we can find anywhere, and as Tobias pointed, its "glare" is one important defect that we should try to fix even paying some loose on efficiency.

    The Nirvana of Caving Headlamps ( I borrowed this from Tobias too ) is not achievable with today technology, but our mission in this thread is to get the best with the technology we have. Even if it is not perfect from a utopist point of view.

    The problem can be avoided by using PWM regulation, but then I need a driver with custom programmed levels and I have no knowledge in how to program the pics common on cheap PWM controlled drivers.
    Well, the idea here would be to make a custom driver capable of driving two LEDs at the same time with different levels of current, and controlled with a rotary switch with 6, 7 or even 8 positions. In order to have such a design done we must start an interest list, but, it should be after we agree in how many levels and how many LEDs... and just if we can get enough people to make it viable and not too expensive for just a few.


    Javier
    Last edited by Barbarin; 01-12-2009 at 11:52 PM. Reason: not all the questions were responded

  15. #75
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Barbarin View Post
    According to my testings any beam narrower than 110º is less than confortable atthe end of some hours, as it will force your neck.
    Javier
    Mmm . you are probably right, I used a 80 degree and thought it was perfect. But that was from comparing it to a 40 degree lamp. And those bad colours from a bare XR-E emitter are actually hard to see as they are far out in periferic vision.
    I measured my field of vision some time ago. About 85 degrees lateral and 150 degrees horizontal. But my two-eyed horizontal is only 65 degrees.
    Hmm, how about using two lamps overlapping each other the in the same area as the eyes? I will do some testing. Probably not a good idea, but Im curious.

    I have also tried the XP-E as bare emitter. It is more uniform in intensity than the XR-E and it's 120 degrees. Very similar to the SSC P4. I didn't measure intensity, but it looked seemed almost half as bright as the XR-E at the same current. But I like how small it is. The dome is only 2,5mm in diameter.

    /Anders Gille

  16. #76
    Flashaholic* uk_caver's Avatar
    Join Date
    Feb 2007
    Location
    Central UK
    Posts
    1,381

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by gillestugan View Post
    Mmm . you are probably right, I used a 80 degree and thought it was perfect. But that was from comparing it to a 40 degree lamp. And those bad colours from a bare XR-E emitter are actually hard to see as they are far out in periferic vision.
    At least at lower power levels, on the extreme edges of a spread beam where light levels fade off, it's possible to have light levels dropping to the point where colour vision just doesn't work well because there simply isn't enough light.

  17. #77
    Flashaholic* hank's Avatar
    Join Date
    Apr 2001
    Location
    Berkeley CA
    Posts
    1,555

    Default Re: Replacement of carbide lamps by LED lamps

    Good for you for starting this topic.

    I have half a dozen carbide lamps, some from my caving days, and a few more I've picked up at garage sales. If I ever come up with any fresh carbide, I'll pull them out and do some beamshots. They are still awesome light sources.

    It would be nice to see measurements of brightness for actual working carbide lamps to compare to the LEDs.

    I've always thought that someone could take a carbide lamp reflector, fit a string of LED emitters where the flame sits, and have a stunningly bright light. It's the 2" or 4" or 6" reflector that really helps. Even thought about hiding a set of batteries and a driver inside a carbide lamp body -- but could never bring myself to gutting one, as they all still work.

  18. #78
    Flashaholic* uk_caver's Avatar
    Join Date
    Feb 2007
    Location
    Central UK
    Posts
    1,381

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by hank View Post
    I've always thought that someone could take a carbide lamp reflector, fit a string of LED emitters where the flame sits, and have a stunningly bright light. It's the 2" or 4" or 6" reflector that really helps. Even thought about hiding a set of batteries and a driver inside a carbide lamp body -- but could never bring myself to gutting one, as they all still work.
    I'd thought of doing a retro-mod to one of the small 'Premier' carbide caplamps that some cavers used to use here, maybe having the water-control lever as a brightness control.
    I suppose one or more LEDs could be fired backwards into the [typically shallow] reflector, but I think the reflectors I've seen are understandably just spherical, rather than parabolic, so they wouldn't give a tight beam.

  19. #79
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by uk_caver View Post
    I suppose one or more LEDs could be fired backwards into the [typically shallow] reflector,.
    One of the real advantages of the carbide lamp is its wide beam, if using total reflection by pointing the led into the reflector you will get little spill. If you point it forward you will get a more carbide looking beam.

    Quote Originally Posted by hank View Post
    It would be nice to see measurements of brightness for actual working carbide lamps to compare to the LEDs.
    There is actually a link to such comparison in this thread. Barbarin has posted interesting beamshots from a cave. One 3W cree Led without reflector against one carbide lamp. The carbide lamp doesn't have a chance.
    This is actually not a surprise as a carbide lamp have a output of 35-100 lumens. (reference) Normally around 50-60 lumen and most of those lumens are spread 200 degrees unless you have a really big and shiny reflector. So 200+ lumens at 80-90 degrees from a LED sure makes a difference.

  20. #80
    Flashaholic* uk_caver's Avatar
    Join Date
    Feb 2007
    Location
    Central UK
    Posts
    1,381

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by gillestugan View Post
    One of the real advantages of the carbide lamp is its wide beam, if using total reflection by pointing the led into the reflector you will get little spill. If you point it forward you will get a more carbide looking beam.
    If you point it forwards, next to nothing would hit a shallow reflector.

    The carbide reflectors I've seen on the smaller caplamps are sections of a sphere, rather than parabolic - they were only ever designed to reflect a flame that had significant length, rather than a point source, and to avoid wasting light backwards, so a spherical-section reflector was fine, and rather easier to make.
    They're also typically not highly polished, so back-firing one or more LEDs into one would probably still give a decent flood, without having a dazzling naked LED to look at.

    Quote Originally Posted by gillestugan View Post
    There is actually a link to such comparison in this thread. Barbarin has posted interesting beamshots from a cave. One 3W cree Led without reflector against one carbide lamp. The carbide lamp doesn't have a chance.
    This is actually not a surprise as a carbide lamp have a output of 35-100 lumens. (reference) Normally around 50-60 lumen and most of those lumens are spread 200 degrees unless you have a really big and shiny reflector. So 200+ lumens at 80-90 degrees from a LED sure makes a difference.
    Some carbide lights are quoted as having an output of 35-100 lumens, but I suspect a proper remote-generator light would be rather brighter than that, at least when turned up for short bursts of extra light when required.

    In my experience with carbide, the main failings were the expense and practical inconvenience of keeping the light supplied with carbide and water.
    That practical side made it a clearly good move to switch to LED lighting, (particularly for extended expedition use), even when I was making my first lights with ~20lm/W Luxeon Is.
    However, I'm sure that most people who used carbide still miss the warmth of the light, not to mention the wonderful heat of a generator clamped between the thighs while sitting around in the small hours in a cave that's still basically at freezing point even in August.

  21. #81
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Yes, the lumen output is of a carbide lamp is more than enough in most situations. And with a 10cm flame you probably get more than 100Lm. But that is really unimportant. I was just trying to make a comparison for hank.
    Regarding the pointed forward led: Some light do will hit the reflector. If the 4" premier reflector is 20m deep it gives an angle from bottom to rims of about 130 degrees. I you put a SSC P4 in the middle 12% of the light would still hit the reflector. (you,re right, it's useless.) And if pointing it towards and old reflector you will probably get a diffused beam, It'll be "almost" like an orange peel reflector, just that is made out of oxide and chrome peel
    And yes. Nothing I've seen beats the colour rendition from a carbide lamp. But its getting better. I have a 3000k cree in a petzl micro mod that is very warm, just a little brownish in the tint.

    Good idea with the water-control lever for brightness. Many lights have fixed steps, which would make it very convenient if used with a potentiometer. (for example a PT4150 driver) And keeping the batteries loose inside the carbide container will give you the rattle of a full light. That would actually be funny, but I too would not be able to bring myself to gutting one. Not a Premier, but maybe a Justrite... hehe

  22. #82
    Flashaholic* Barbarin's Avatar
    Join Date
    Jul 2001
    Location
    Pamplona- NA- Spain
    Posts
    1,305

    Default Re: Replacement of carbide lamps by LED lamps

    I've been thinking about a "CarbiLED" too. In fact that would be the most similar to a pure flood style light. (as carbide is)

    Let's imagine. Using a 70 mm diameter alloy disc , 7-8 mm thick, with some finning on the back would allow enough heatsink . A protective "frozen" polycarbonate lens like 3 mm for a single XR-E (maybe 3 in series to reduce glare and improve efficiency) , and the batteries placed on a kind of "generator" holding 4x18650's or alternatively 8 x CR123 , with a potentiometer from 1% to 100% ( 10-1400 mA). Runtimes from 6 hours at 300 lm;24 hours if we just need to be over a good carbide specs (more than 100 lm) ; and ranging from one day to two weeks on low levels.

    The generator hanging from your waist, hitting every rock, that flat disc on your helmet will look like an old style flamme reflector, the control next to your waist, the cable... That would be for sure really similar to carbide. (Not replacement, but similar). And simple and "cheap"* to make. Sorry, no smell, no heat.

    In fact making a pure flood light will make things really easier... and if you just need a "thrower" for very short moments, why don't carry it on a pouch?? Just a different approach.

    Not the purpose of this thread, as the idea is to get the best lamp available designed for the needs of caving, with the technology we have today. But just wanted to talk about it.

    Javier

    *It could be made cheaper if using no driver, DD resistored down with the potentiomenter, and a 3 X D NiMH battery pack with this battery holder on the 3D version and "moddified" to be IP67 at least.(The C version looks better and can be used for 26650's ).


    Last edited by Barbarin; 01-14-2009 at 01:05 AM.

  23. #83
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Regarding the anti-glare:
    I just made some tests with a piece of lightly frosted glass from a reflector bulb. The loss was very small and it reduced the glare significantly. Unfortunately it is frosted on the inside, so it wont be possible to glue it on top of the led with optical resin, and it is very fragile in it self. Would be nice to find some kind of thicker and curved lens that is just as lightly frosted.
    Do you think it would be possible to diffuse the Carclo 10403 120 deg Bubble optics?
    The Khatod PLJT20 20mm Diffused dome has been mentioned, but I am afraid it will give too low output. Especially as it is 170 degrees. The test report doesn't give any information on the output, as the output the led used in the test is not specified.

    EDIT: I just saw there is. But I cant understand and match the numbers to what is said in the text. Someone please explain. How much lower is the lux level of the LED with the lens on? 1/3,2?
    Last edited by gillestugan; 01-14-2009 at 10:51 AM.

  24. #84
    Flashaholic Tobias Bossert's Avatar
    Join Date
    Oct 2007
    Location
    Germany, Munich
    Posts
    145

    Default Re: Replacement of carbide lamps by LED lamps

    I will complete the test report. Gottfried, the tester of test device_2 ('Bucherl'), took some photos. With the link you can compare Scurion P4, Petzl Ultra and my test device_2 (Tobi) side by side.

    http://www.hirlatz.at/lampenvergleich.html

    "Anmerkung 1:" = Note 1
    "comparison of light distribution 1


    left: "Scurion P4" flood on level 3,
    right: "Tobi 1" work-light low


    The light of Scurion decreases strongly with distance, with Tobi's worklight you can see more far. This is achieved by the light-up with smooth transition."


    "Anmerkung 2" = Note 2


    It is the same text but comparing Scurion P4 maximum flood (level 4) with Tobi's work-light high.


    (Comment: Please realize that level 4 of Scurion is about 1A to the LED, but my work-light is 295mA + 91mA only.)


    The room in the cave is covered with very dark loam, absorbing a lot of light. The caver stands immediately beside a wall (left to him). The floor decends slowly, increase again a little bit and - in a distance of about 15m - falls again and thus is hidden. The wall at the other side of the large room is far away. With the adapted eye you can see it with each light ghostly, but in the photos with fixed exposure it seems to be totally black - with the exception of my shaft-light.

    My personal conclusion from these photos is, that it is NOT possible to use a two-LED construction with fixed beams! For normal use as a work-light, a relativly narrow beam makes no sense - even when combined with a diffuse light: You need a very soft transition from beam to flood and the beam should not reside in the centrum of the flood.

    I'm verry interested in Javiers two-LED solution with zoom - but I'm jet not convinced that the transition of the superposition of both parts would be smooth enough to use it round the clock. I'm not shure whether the two-LED solution will be easyer to construct and will have lower weight as the three-LED solution with fixed diffuse/medium-beam/extra-narrow.

    But never the less, I'm very eager to see some photos from Javier dealing with this. He is experienced in manufacturing and he also convinced me with his zoom-light: Much better than all I have seen in the past.

    I agree with the schematic drawings of Javier completely: That's what we need.

    At the moment I'm still looking for spherically domed front glass with diameter 18 to 20mm and dome height of 4 to 5 mm (spherical cap with 90 deg opening) to make some experiments with domed diffusers. This diffused light would be need to avoid glaring anyhow, whether we end up with a two-LED or with a three-LED solution.

    Tobias
    Last edited by Tobias Bossert; 01-14-2009 at 04:24 PM. Reason: Added some translations of German link

  25. #85
    Flashaholic* uk_caver's Avatar
    Join Date
    Feb 2007
    Location
    Central UK
    Posts
    1,381

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Tobias Bossert View Post
    My personal conclusion from these photos is, that it is NOT possible to use a two-LED construction with fixed beams! For normal use as a work-light, a relativly narrow beam makes no sense - even when combined with a diffuse light: You need a very soft transition from beam to flood and the beam should not reside in the centrum of the flood.
    Maybe it's not *ideal*, but a fixed two-beam solution is not only possible, it's what most people would consider as good enough.
    If you mix a flood beam with a rather narrow spot, even a spot that's really too narrow for optimal floor-lighting close-up *and* with a fairly defined edge, that still seems to work as a usable light, since the flood lights up nearby things adequately, if not perfectly.

    Quote Originally Posted by Tobias Bossert View Post
    At the moment I'm still looking for spherically domed front glass with diameter 18 to 20mm and dome height of 4 to 5 mm (spherical cap with 90 deg opening) to make some experiments with domed diffusers. This diffused light would be need to avoid glaring anyhow, whether we end up with a two-LED or with a three-LED solution.Tobias
    Practically speaking, I think even having a small and somewhat matte 'reflector' round a flood LED *might* make the glare problem less severe.
    Though I'm only speaking from a subjective viewpoint, after I (and most people I cave with) moved from using naked LEDs for flood to LEDs with a small reflective collar, I got less feeling of the other people's flood LEDs being annoyingly glaring.

    Possibly it's just that a larger source is somehow easier to avoid looking at than a bare LED, possibly it's just that over time I got gradually better at avoidong looking at other people's lights and the small reflectors had nothing to do with it.
    However, when making lights, I do find that there's something about naked LEDs that just doesn't seem to annoy my eyes enough to make me automatically look away from them.
    I wouldn't be surprised if there's some kind of brightness-avoiding reflex that isn't properly triggered by very small sources

  26. #86
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by uk_caver View Post
    Possibly it's just that a larger source is somehow easier to avoid looking at than a bare LED, possibly it's just that over time I got gradually better at avoidong looking at other people's lights and the small reflectors had nothing to do with it.
    The smaller the light source is, the smaller is the area it is hitting on the retina when focused by the eye. The smaller the area the lumens hit, the brighter and more annoying it it is to the eye.
    This is a problem when you want to make a small and light lamp, as you ideally would have a very large dome on your head

    Looking at the pictures (thank you Tobias!) I agree that it is not working very well with the two lamp system. That is with those very narrow optics.

    I still think you could get satisfying results with only two lamps, but then I would choose a wider spot and softer edge, around 10 degrees. Of course this gives a loss in shaft lighting performance, but it is not often you have to look down those terrible deep shafts. You usually know beforehand if the caves have shafts like that and can carry a small CR123a handheld for those moments. But then, one Boom medium on a MC-E for hall light would also be very nice to have.

  27. #87
    Flashaholic* uk_caver's Avatar
    Join Date
    Feb 2007
    Location
    Central UK
    Posts
    1,381

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by gillestugan View Post
    The smaller the light source is, the smaller is the area it is hitting on the retina when focused by the eye. The smaller the area the lumens hit, the brighter and more annoying it it is to the eye.
    This is a problem when you want to make a small and light lamp, as you ideally would have a very large dome on your head.
    I take your point, however, I'm talking about surrounding flood LEDs with small semi-matte reflectors, not optics or diffusers.
    With a small reflector, someone looking at the light from within ~50 degrees of the lamp axis can still see the naked LED just as before, and just as bright as before, only now with a surrounding area of lit reflector. That does seem to be less dazzling, even though the peak brightness on the retina is the same as previously - possibly it's just easier to automatically avoid looking at.

  28. #88
    Flashaholic gillestugan's Avatar
    Join Date
    Nov 2007
    Location
    Nora, Sweden
    Posts
    242

    Default Re: Replacement of carbide lamps by LED lamps

    Thanks for the clarification, I thought you meant the light reflected by the orange peel reflector. I see your point and agree with you, although a large diffused lens is much less annoying. I have no idea of the cause of the effect with the reflector, it may very well be like you say that the very small sources doesn't trigger the reflexes as it should. Sometimes body (and mind) works in strange ways. The pain caused by dazzle in one eye will for example get lower if you close the other eye. This is really weird.
    When talking about glare: Older people suffer more from glare than young people as may take them 3 times as long to recover from it, so if you feel like shining someone in the eyes- go for the youngest.
    One thing to consider is that blue light gives a more annoying glare than warmer tints, compared at same brightness level. Another reason to go for a warmer tint... I am a big fan of neutral-warm tints.

  29. #89
    Flashaholic Tobias Bossert's Avatar
    Join Date
    Oct 2007
    Location
    Germany, Munich
    Posts
    145

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by uk_caver View Post
    I take your point, however, I'm talking about surrounding flood LEDs with small semi-matte reflectors, not optics or diffusers.
    With a small reflector, someone looking at the light from within ~50 degrees of the lamp axis can still see the naked LED just as before, and just as bright as before, only now with a surrounding area of lit reflector. That does seem to be less dazzling, even though the peak brightness on the retina is the same as previously - possibly it's just easier to automatically avoid looking at.
    I also made tests with semi-matte reflektors. This works relatively fine with SSC P4 but helps not really with Cree XR-E, since the reflector is hit by a too small fraction of the overall flux when you use an ful width angle of 90 deg. Than the reflector gathers the yellow-greenisch surrounding of the original beam of the XR-E only.

    And there is another problem with "only reflector": You get a visible edge!

    Therefore I remain so far by the solution of test device_2: XR-E plus Carclo wide angle reflector plus diffuser front lens. This works fine, it gives about the same spatial distribution as a bare XR-E but glaring is reduced dramatically. And the diffuser - I used a plane glass lens etched on the inner side - guarantees that there is no visible edge.

  30. #90
    Flashaholic* uk_caver's Avatar
    Join Date
    Feb 2007
    Location
    Central UK
    Posts
    1,381

    Default Re: Replacement of carbide lamps by LED lamps

    Quote Originally Posted by Tobias Bossert View Post
    I also made tests with semi-matte reflektors. This works relatively fine with SSC P4 but helps not really with Cree XR-E, since the reflector is hit by a too small fraction of the overall flux when you use an ful width angle of 90 deg. Than the reflector gathers the yellow-greenisch surrounding of the original beam of the XR-E only.
    That's true - I tend to use SSCs most of the time since they work better for me in my layout than the more centrally-biased Cree.
    I think that adding a small collar to an SSC can give a nicer flood beam than a naked Cree, while also increasing the apparent size.

Page 3 of 5 FirstFirst 12345 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •