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Thread: bLu vs. tLu: IS confirms 65% conversion factor

  1. #91
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by mpteach
    If I can sum this up, untill we get access to quality reflector coatings and AR lenses that are durable enough to actually use, 35% of the light generated in our incandescent lights wont leave them. When we do get the good stuff 15-20% more of the light will get out.


    I have a question too. How much output can be lost to fingerpnrints on the the outer side of the lens ? AR coated and regular lenses.
    If it's bad enough it can be like 10%-30%. Like using a stock mag lens "blocks" ~5% more light than a UCL. In some cases in old mags you can notice a huge difference when you replace the old lens with a new plastic one from mag, because fine hairline scratches can claim quite a bit.

  2. #92
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by mpteach
    If I can sum this up, untill we get access to quality reflector coatings and AR lenses that are durable enough to actually use, 35% of the light generated in our incandescent lights wont leave them. When we do get the good stuff 15-20% more of the light will get out.


    I have a question too. How much output can be lost to fingerpnrints on the the outer side of the lens ? AR coated and regular lenses.

    I've yet to see any flashlight lens provider offer it, but there is a coating that can be put on the AR that is oleophobic and hydrophobic, which doesn't fingerprint or smudge, nearly repels dust, anti-static and makes the lens very easy to clean. It has been a number of years since it has been available, and it is only a matter of time before someone offers it.

  3. #93

    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by NewBie
    I've yet to see any flashlight lens provider offer it, but there is a coating that can be put on the AR that is oleophobic and hydrophobic, which doesn't fingerprint or smudge, nearly repels dust, anti-static and makes the lens very easy to clean. It has been a number of years since it has been available, and it is only a matter of time before someone offers it.

    Is that similar to this http://www.schneiderkreuznach.com/knowhow/mrc_e.htm

    Theyre not cheap. http://www.bhphotovideo.com/bnh/cont...ughType=search

  4. #94
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Actually, if you buy in batches, you can get the additional coating for nearly nothing in comparison to the cost of the normal AR lens.

  5. #95

    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Besides the expensive 52mm photography filters, I have seen 2" and 50mm AR windows which are reasonably priced, will these fit a D mag??


    Some people will spend rediculous amounts of money to get the highest performance materials, but AR coatings are actually economical at higher power levels. For instance im buidling a mag 2d w/ an overdriven 50w or 65w IRC bulb.

    At 3700L an 8% increase in output is roughly 300L. I wouldnt mind spending $20 for a durable and AR coated lens instead of $5 on a simple borrofloat one. And even more so for a good reflector.

    How long does it take for an unprrotected aluminum reflector to heavily oxidize?

    Edit: What % loss is there using a stippled reflector?
    Last edited by mpteach; 10-22-2006 at 03:55 AM.

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    *Flashaholic* bwaites's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Most of the AR coatings won't stand up to the heat from the 100 watt lamps, and the windows are not Borofloat so they will shatter!

    Ask me how I know!

    There were some heat treated UCL's made, and I did have one of those last a few months in a USL before if finally gave up the ghost and shattered one day.

    Bill
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by bwaites
    Most of the AR coatings won't stand up to the heat from the 100 watt lamps, and the windows are not Borofloat so they will shatter!

    Ask me how I know!

    There were some heat treated UCL's made, and I did have one of those last a few months in a USL before if finally gave up the ghost and shattered one day.

    Bill

    Oh, you mean in close proximity. The Thor 10MCP and 15MCP use nothing more than ordinary window glass (soda lime float) and even that does not shatter.

    If I recall correctly, UCL is simply low iron soda lime (aka crown glass), where the glass itself has a little bit less transmission loss, and thus the glass tint shifts from green to brown to yellow, to water white when looked at edge on, as the amount of iron impurities is reduced.

    And B270 is a high quality optical grade of Pyrex, which is what those lab beakers you do chemistry experiments over flames, are. B270 is actually a borosilicate glass. Other names for borosilicate glasses are, Pyrex ™ by Corning and Duran ™ or Borofloat ™ by Schott Glass. When heated, it's expansion rate is 3 times less than soda lime glass. Borosilicate glass is mechanically stronger and harder than soda lime glass.

    Quartz is higher up on the list, it's thermal shock resistance is even better which has a coefficient of expansion ~60x less than even the borosilicates. It has a continuous maximum working range of 900C to 1100C, depending on the size and shape of the part. It can be used up to 1400C for short periods of time.

    Not all AR coatings are created equal, nor are they deposited equally.


    AR coatings can be put on window glass, UCL, B270, quartz, sapphire, mineral glass, quartz, and more.


    There are two typical ways of depositing AR coatings, one is vacuum and the other is sputtering. Usually, the vacuum deposited coating is more durable and higher quality, but it is slightly more expensive. One of the processes I've seen, heats the AR coating material above 2,227 °C in the process, to turn it into vapor, and it condenses on the glass.

    As far as shattering, consider how many folks will mount the lens in a Maglite, and the edges of the glass are cooled by the metal housing, while the center is heated. Thats a shatter scenario.

    Even sapphire and mineral glass can be thermally shocked and broken if not heated uniformly.

    Magnesium fluoride itself (which is what most AR coatings are made from) is a proven window material for power Eximer lasers, but over time, it will color a bit, even under this high power assault.

    Bwaites-

    I believe your issue is not the AR coating, but the lens substrate, and un-even heating of the substrate. Some substrates (the glass), are more prone to shattering due to high stress levels, caused by uneven heating.

    Last edited by NewBie; 10-22-2006 at 11:15 AM.

  9. #99

    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Do you know where to get ar coated b270 lenses that fit mags?

    Isnt quartz sensitive to fingerprints though? I know that im not supposed to tuch 500w halogen work light bubls directly.

    I broke a pyrex measuring cup heating water on a stove burner. However i have pots that are a really yellowish brown glass that are made for that and fine. What kind of glass are they?

  10. #100
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    I'm getting together a thread on Lamp Physics that I hope to post sometime soon, as it's all been sort of obsessing me lately--ever since the 60 l/watt thread on the Osram IRC lamps and this post that I made to it.

    Backing up, for starters, Luna was right. IF you know the CCT of a lamp filament, THEN you know its Temperature, and IF you know its geometry, it's pretty straightforward to come up with the total resistance of the filament at that temperature, or I should say, at that average temperature, with the average being defined in some reasonable way.

    Also, Luna was right, for the most part, in saying that using xenon as the fill gas allows for greater efficiency by allowing for a hotter filament that nonetheless has the same rate of vaporization as a cooler filament in a nitrogen/argon fill gas.

    Good for you Luna!

    That said, I will bring back a quote of my own from earlier in this thread:

    As for CCT, I didn't mean to say that one couldn't re-rate CCT based on knowing an applied voltage and a design voltage and design CCT at this voltage. What I said was that you cannot accurately determine a lamps CCT from its voltage, current, lumens output, and life rating.
    And that was at the heart of my unfortunate argument with Luna. And I stand by that. And the whole IRC issue brought everything to greater clarity for me regarding this.

    Because, the electrical current used to power our lamps is only a means to keep the filament glowing hot. It's the hot tungsten that radiates the light, because IT IS HOT, and not because current is flowing through it.

    Next, the real issue is that what we directly control is not the filament temperature, but rather the applied voltage (or current in some unusual cases). A voltage is applied, current flows, the filament heats up until it reaches a steady state situation where the power applied to the filament equals the heat lost due to radiative cooling of the tungsten filament blackbody radiation and convective cooling due to the moving fill gases within the envelope. The temperature and motion of the air outside of the bulb envelope, as well as any radiation incident upon the filament itself (such as from a nearby reflector), affect the rate of heat-loss, and thus the temperature of the filament. But change the filament T and you change its R and you thus change the current. In all of its messy glory it is VERY complicated--and I mean from a theoretical perspective, including the convective gas flow currents within the envelope and just outside of it, as well as the blackbody radiation formulas and rate of vaporization formulas and so on.

    However, some qualitative things can easily be ascertained. For one, if you reflect the radiation, or any part of it, back towards the filament (the blackbody), then it will increase in temperature FOR THE SAME APPLIED VOLTAGE, and thus the current drawn will DECREASE, and thus the power will decrease. Now, if the visible light is allowed to pass through the reflective layer, then the lumens output will INCREASE at the same time that the POWER will decrease. This is the idea behind the IRC coating. In principle, it's as simple as insulating your house. The same woodstove burning at the same rate will now keep your house much warmer than before it was insulated. OR, you can keep the same temperature with a REDUCED amount of wood burning. Insulation. That is, in essence what the IRC coating achieves.

    So, anyway, I was going through my physics books, reviewing the blackbody curve and total radiative power of a blackbody of area A and emissivity e at temperature T (in Kelvin, of course), and I decided it would be fun to apply it to a known lamp, such as the Welch Allyn 01111-u.

    Great idea, I said to myself. It is a 6.0 v, 3.35 A, 20.1 W, 465 lumen lamp running at a CCT of 3,325 K, with a life rating of 100 hours. A quick division shows it to have a 23 lumen/watt efficiency.

    Now, that struck me as low for a filament running that hot. According to what I've read, a 3,300 K filament should have about a 30 l/w efficiency. Hmmmm. What was going on?

    Then I remembered a conversation I had with David Harchenko of Carley Lamps. I was spec'ing a lamp and getting a quote on it, and we were talking about CCT and I mentioned a Welch Allyn lamp, and David immediately stated that WA always arrived at significantly higher CCT's than Carley did. He said he thought that they focused right in on the center coil of the filament for their measurement, whereas Carley had a different procedure that gave a much more realistic assesment of the true blackbody equivalent temperature.

    Interesting, is it not? At the very least, it implies that there is no standard way to define or measure the CCT of a filament.

    So, that got me curious. So I looked up some Carley lamps, and examined the Carley 852. It is also a Halogen lamp, with a xenon fill, and it is also a 6 volt, approximately 20 watt lamp, so it would make for an interesting comparison:

    6 volts, 3.3 amps, 19.8 watts, 40 MSCP = 500 lumens, driven at 3100 K, with a 20 hour life. These figures yield an efficiency of 25 lumens/watt. Now, if at 3300 you have 30, and if for every 100 K difference you add or subtract 3 l/w, then this lamp at 3300 comes in at 31 lumens/watt (add 6 l/w for the 200 K rise). That's pretty darn close, isn't it. Plus, look at the life rating. 20 hours of life.

    See the difference? WA1111 at 3325 K gives 100 hours, but a Carley 852 at 3100 K gives 20 hours? Say what? Something is definitely wrong there, isn't it? And if it were going to be skewed in one direction or the other, it should be skewed IN FAVOR of the 852, which is xenon filled and thus suppressed vaporization of the filament better than the Krypton fill of the WA lamp.

    So, what I'm getting at here, is that the CCT of a lamp is something difficult for us to measure, or calculate, based upon the information we have. The best we can do is compare known sources (from integrating spheres) against unknown ones, via the good ole eyeball. And doing so, I can say that the Welch Allyn 1111 at 6.0 volts is no friggin 3325 K filament. Not if the A2 is. Because the A2 is whiter than the 1111 at 6 volts. Noticeably whiter.

    So, I don't think it's any accident that there isn't any formula for deriving CCT from volts, amps, and filament geometry. If the filament were a nice sphere instead of a helix, and if you could ignore convective cooling and assume a pure blackbody in a vacuum with no reflected radiation, then you can do it pretty easily. But the fact is that

    1. A filament coil is a whole lot more complicated, and has a temperature which varies with spatial location.

    and

    2. Convective cooling will depend upon the pressure and composition of the gas mixture, and the shape of the envelope and filament and support wires and so on.

    However, if anyone thinks he or she can do it, I would absolutely LOVE to see a formula for the CCT of a filament based upon the voltage, current, and geometry. Then let's try it out on some known lamps. Or even throw in hours of life as a known variable. Even then, I doubt it could be done.

    Anyway, as I said at the start, I will be putting together a primer-type thread on Lamp Physics at some point. So if I am in error on any of this stuff, let's work it out now, before I start working on the final version of that.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

  11. #101
    Flashaholic PANZERWOLF's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by js
    A smooth, vacuum aluminized reflector with a Welch Allyn 01274 lamp potted into it was sent to an integrating sphere to be measured for total beam lumens, or MSCP (=total lumens/4 pi). This lamp is rated at 553 lumens at 7.2 volts. 7.2 volts was applied at the pins and 391 lumens was measured in the sphere.
    i don't want to be picky, but i wouldn't underestimate the difference between being "rated" and being measured in your sphere, so i think that measuring both with and without reflector could have given a bit different numbers

  12. #102
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Newbie,

    Actually the AR coatings I was talking about are those used on the UCL lenses.

    They literally bake off if left too close to the lamps, I have found this to be the case even with a 1499 run in a MiniMag.

    Somewhere I have a UCL lens that has no coating in the center, (it's quite easily seen, looks like a donut).

    As far as other coatings, I defer to your superior knowledge!

    What I have observed is two things:

    The glass shatters at high temps, OR, the AR coating bakes and vaporizes leaving a funky uneven covering, and then eventually the glass shatters.


    Bill
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  13. #103
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by PANZERWOLF
    i don't want to be picky, but i wouldn't underestimate the difference between being "rated" and being measured in your sphere, so i think that measuring both with and without reflector could have given a bit different numbers
    The 1274 was driven at the rated voltage, so I think it's safe to trust the manufacturer's MSCP rating on this.

    But, if you want to PayPal me $125 I will have them test a bare 1274 at 7.2 VDC for us.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

  14. #104
    Flashaholic* woodrow's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    js. I will be brief because I am WAAY out of my depth in this discussion...But I wanted to say thanks from myself and most likely some of the other non scientists here.

    I just bought a gl4 with a "550" lumen lamp. It is very bright and I like it a lot, but it does not seem much brighter than my 10 watt hid. The hid supposibly has a "500 luman" bulb as well, but I have read a post from a person who has both my hid light and a M6, and the M6 was reported to be easily brighter.

    Basicly to me, your 65% information helps me solve a mental problem I have been having. It also makes me proud of Surefire for posting torch lumens instead of bulb lumens.

    So as I understand all this---My gl4 and lc100 are producing around 360 lumens more or less at the front end of the lights. If I want to spend $380.00 additional I can have a M6 that will be brighter than both-using 6 batteries for 20 minutes.

    All of this makes me feel better because the mighty M6 is not beaten by my $86.00 light, but lumans per dollar, I did ok.

    Ok, I will leave now and go take some excedren with some crown royal so I can forget all that metal coating and refracting stuff. Thanks for the info though.
    "I only smile in the dark...my only comfort is the night gone black..."lyrics from Garbage

  15. #105
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by bwaites
    Newbie,

    Actually the AR coatings I was talking about are those used on the UCL lenses.

    They literally bake off if left too close to the lamps, I have found this to be the case even with a 1499 run in a MiniMag.

    Somewhere I have a UCL lens that has no coating in the center, (it's quite easily seen, looks like a donut).

    As far as other coatings, I defer to your superior knowledge!

    What I have observed is two things:

    The glass shatters at high temps, OR, the AR coating bakes and vaporizes leaving a funky uneven covering, and then eventually the glass shatters.


    Bill

    Do you find that borosilicate/borofloat also shatters? Glasses like Pyrex are made from this stuff, and are used for cooking ware and even lab beakers that you put on bunsen burners.

    As I recall, Silicon Dioxide AR coatings are more durable to high heat and a bit more rugged. They will typically have a greenish tint, where properly applied Magnesium Flouride has a purplish tint under strong light.

  16. #106
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Okay, so in a nutshell, after all the genuflecting the 65% conversion factor was confirmed for reflector and lens losses thru actual measurement.

    If my memory serves correctly, Gransee's integrating sphere tests confirmed also that mineral glass adds 14% loss to the equation, refering to the HDS light that had the sapphire/mineral glass lens installed 50 lumens, then it was removed and measured 57 lumens.

    Andrew-
    Yes, how much of the exiting light hits the reflector surface should definitely have a large play on things, as the reflector coatings used in flashlights are quite lossy.

    bwaites-
    Did you catch my last post yet?
    Last edited by NewBie; 01-09-2007 at 09:13 AM.

  17. #107
    *Flashaholic* bwaites's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Thanks Newbie, just saw it.

    I haven't had any Boro lenses shatter from heat, it's why I used them in the USL.

    The UCL lenses aren't Boro, though. flashlightlens.com did have some heat strengthened UCL lenses, and I didn't have them shatter, even in USL's, although the antireflective coating did disintegrate over a few sessions.

    Bill
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Good to know.

    Sure would be interesting to try the Silicon Dioxide based AR coatings, since they are much more durable under heat, as compared to Magnesium Fluoride. Of course, not all Magnesium Fluoride AR coatings are equal either.

  19. #109

    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    I learned a lot from this thread. Lots of people are comparing bulb lumens and out the front lumens as if they were the same thing. I still prefer a FlashlightReviews.com style light box measurement to get estimated lumens, but if you can get an accurate rating of a bulbs lumens, the 65% rule of thumb seems to work very well.

    For the most part, this thread is a good example of people arguing the science and not getting bogged down with personal attacks.
    Last edited by Art Vandelay; 04-07-2007 at 04:51 PM.

  20. #110
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Thanks, Art!

    I'm afraid I am responsible for a lot of the in-fighting that went on in the middle part of this thread! But, it settled down after that.

    And yes, absolutely, a lumens box estimator is a way cool device. Along with ceiling bounce methodology and other methods for trying to quantify what the output of a light IS, and how it compares to other lights, and so on. The amazing thing is that various CPFers managed to narrow in on the 65 percent figure, and it allows creators of many mods to go from bulb lumens to torch lumens with a reasonable amount of accuracy. This benchmark figure was attacked pretty hard by Luna back in one of Lux Luthors early threads in the general forum, and I was the one arguing with him. And so when he popped in early on and acted so cavilier about accepting it, I got more than a little steamed about it. My bad! But, as I said, we moved on to more productive discussion.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

  21. #111

    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    This benchmark figure was attacked pretty hard by Luna back in one of Lux Luthors early threads in the general forum
    Never attacked, only questioned since it was never confirmed...to that point
    Last edited by Luna; 04-10-2007 at 07:57 AM.

  22. #112
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Hey Luna! How are you?

    Yeah. You're right. But I took it as an attacking kind of questioning at the time, hot-head that I am. Sorry.

    BTW, please go back about a dozen or so posts and read my comments on CCT as measured by Carely vs as measure by Welch Allyn! I was hoping you would give me your thoughts back when I first made those posts. Post #100 in this thread is what I am refering to, mainly. Check it out, and let's see what we can figure out! I'm still pretty far away from having my lamp physics thread ready, so I could use your opinions on this. Let me know.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

  23. #113
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    I just read this entire thread as I had missed it previously. Thanks Jim and Newbie, another ton of good info learned!!

  24. #114

    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by js
    Hey Luna! How are you?

    Yeah. You're right. But I took it as an attacking kind of questioning at the time, hot-head that I am. Sorry.

    BTW, please go back about a dozen or so posts and read my comments on CCT as measured by Carely vs as measure by Welch Allyn! I was hoping you would give me your thoughts back when I first made those posts. Post #100 in this thread is what I am refering to, mainly. Check it out, and let's see what we can figure out! I'm still pretty far away from having my lamp physics thread ready, so I could use your opinions on this. Let me know.
    With a four almost five month old in the house, I've missed a bunch Hehe I just enjoy debating/playing anyways, as do alot of us as I can tell...that is part of the fun... so hopefully nobody will take me as an ass as I can sometime seem.

    I'll try to catch up on the articles, so if anything else big has come about lately point me in the direction.

    Take care!

    -Craig

  25. #115
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Quote Originally Posted by PANZERWOLF
    Quote Originally Posted by js
    A smooth, vacuum aluminized reflector with a Welch Allyn 01274 lamp potted into it was sent to an integrating sphere to be measured for total beam lumens, or MSCP (=total lumens/4 pi). This lamp is rated at 553 lumens at 7.2 volts. 7.2 volts was applied at the pins and 391 lumens was measured in the sphere.
    i don't want to be picky, but i wouldn't underestimate the difference between being "rated" and being measured in your sphere, so i think that measuring both with and without reflector could have given a bit different numbers
    I've been thinking some more about this, and I actually think that it was more instructive to use the rated lumens of the lamp as given by Welch Allyn, compared to the measured lumens, because everyone is using the WA ratings (or re-ratings) and very few people (if any) are able or willing to measure bulb-lumens in an IS to start with.

    So if there is any systematic difference between the two: WA ratings/re-ratings bLu vs. measured bLu, we want to go with the one that people will be using and adjust from there in order to come up with our transmission efficiency.

    However, all of that said, I agree that ideally, we would measure the bare lamp, then the lamp in a reflector, then maybe even the LA in a flashlight with various lenses, and all that. But, hey, I'd like to get IS measurements of all the various SF M6 LA's at start, 5 minutes into, middle, and end of, run, but that's not going to happen anytime soon. That would cost, , on the order of $1,200, not counting the batteries.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

  26. #116
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    I still plan on someday doing a thread on the physics and design of tungsten halogen low-voltage lamps, but I really haven't made much progress in the way of actually starting a draft of the thread, or even collecting some in-house manuals and documentation from, say, Carley and Welch Allyn. However, I've got to do some dealings with Carley in the next week or two and I may ask their lamp engineer to send me that stuff. He had at one time promised to do so for me, but never did and I never bothered him about it as I was busy with other things. But, I really would like to collect together all the stuff to make a lamp physics thread, which will cover all the basics, as well as things like quartz glass vs. hard glass envelopes, IRC coatings, and so on.

    And, I also just wanted to bump this thread to the top again. Been a while since it was there.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

  27. #117
    Super Moderator
    DM51's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Thanks for bringing this one up again, js - it's well worth a re-read.

    If you come to do something on the physics, Ra posted some interesting stuff in this thread about reflector absorption, coatings, TIR efficiency, etc etc.
    Resistance is futile...

  28. #118
    *Flashaholic* LuxLuthor's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    I miss NewBie.

  29. #119
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    Pretty interesting stuff. A bit over my head but glad someone is working on this.

    Does "UCL® Lens 'Water white' glass with a high performance anti-reflective coating on both sides." coating burn off with 100w mods common here?

    thanks jim

  30. #120
    *Flashaholic* js's Avatar
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    Default Re: bLu vs. tLu: IS confirms 65% conversion factor

    jimjones3630,

    No. The AR coating stands up. The problem is that the glass itself sometimes doesn't. UCL's will sometimes crack due to the intense heat and IR. The borofloat glass is the material of choice for high powered incan mods, and has proven that it can stand up to repeated 100W or higher burns without cracking.

    DM51 & LuxLuthor,

    My lamp physics thread won't have any information on coatings and reflectivity and reflectors and all that stuff. It will be purely about the lamp and its components and the physics underlying it all--CCT, I-V, temperature, fill gas, etc., characteristics.

    Besides, as LuxLuthor points out, NewBie already covered a lot of the ground on geometrical optics and coatings and efficiencies and all that. These posts/threads still exist and can still be read.
    -Jim Sexton, creator of the M6-R, the TigerLight Upgrades, Fixture-ring lamp potting, the SL60, co-designer of the B90 Upgrade, and proponent of the SF A2, the SF M6 X-LOLA, Titanium, the Haiku, and the LunaSol 20

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