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  1. #1
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    New Testing Equipment

    IN DIY sub as well (by mistake)

    Well the light geek in me got the better of me. At first just built the sphere, not good enough. 80mm thick foam sphere (lots of research digging on how to do it). But set up to do bike lights and flashlights. The upside of having action cameras and doing a couple reviews of them, plenty of extra gopro style mounting parts.




    Wanted to be able to run bike lights for extended periods with proper air flow. So added a "cooling tube". The upside of 80mm thick walls, can do all kinds of stuff without affecting the integrity of the inner sphere. press in t nuts and some foam safe CA can do amazing things. YES THE TUBE IS EASILY REMOVABLE. And you can see it, but I made adapters plates to close up the whole around the lights, quickly changeable with tube off. Tube is just held on by 4x M4 short screws into the t-nuts.



    You can see at the interface to the sphere there is inlets on all 4 sides, all tapered to "scoop" air in towards the lights heads then back over them. Fan is set on "suck" through the tube. Preliminary testing has been great so far.

    For convenience I moved my Voltage/Amp display onto the sphere base. Both fan and display are on DC connectors, then I made a "y" for each to plug in separately. Then own wire coming off with standard DC connector again to plug into my normal PSU or a wallwort so sphere can be totally stand alone and easier to move upstairs or to the garage.




    And totally finished:




    Then, in honor or Andy dubbing my contraption to generate air flow for testing thermal management of light heads the "Wind Tunnel", I found a BIG 120mm 12V fan at radio shack on clearance for $9, hehe. New Anemometer should be here tomorrow (didnt want to bug my friend to borrow his again). Fan set to "suck" through the tub as it gives the most evenly balanced air flow through the tube.

    .


    NOW HERE'S THE REASON THIS BELONGS HERE

    Work in progress, but now youll be able to see full comparisons of every light I have, I review, I build, whatever. If its a bike light or flashlight I end up with, it will end up on these sheets. Plan to do run time graphs of output and everything. Taking alot of time to build the sheets, relearn how to do graphs and all that, but its coming along. Then have to run the tests on everything (that I feel is worth testing).

    Lumen Outputs of my lights

    I do have a stock Yinding I need to put back together, but that's the only "unmodded" light I have that's not listed but can be functional.

  2. #2
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    Very cool tigris! Funny but was just contemplating the purchase of a 12V fan myself. Hope my local RS has the same kind of deal going on.

    BTW, could you devise a means of measuring color temperature as well?

    Thanks for all your work on this!!!

  3. #3
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    The only way to do color temp is the same way I have been doing it. The tool needed to be able to do that is $1000+, so my eyes comparing against other tints is the best I can do.

    Well I am planning on getting a full selection of emitter tints and making a piece of board that's smooth, flat white to make a way to compare tints/color temps.
    Last edited by tigris99; 01-26-2016 at 12:03 PM.

  4. #4
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    Hummm...either you're the ultimate "Light Geek Par Excellence" or someone trying to build a "Thermonuclear device" and then trying to pull the wool over everyone's eyes.......hopefully the former ( and not the latter ).

  5. #5
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    Well I got my son a mini quad copter for Xmas, good delivery system

    Its a cross between being a light geek (though can't afford to be like Artur or those other guys with the fancy equipment and knowledge) for doing reviews/having fun when i cant ride and having a "project" I'm slowly working on.

  6. #6
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    Quote Originally Posted by tigris99 View Post
    Well I am planning on getting a full selection of emitter tints and making a piece of board that's smooth, flat white to make a way to compare tints/color temps.
    Think if you print out the LED color graph, then what ever tint square matches the illuminating emitter will disappear into a white background, if that makes any sense. Couldn't find the one I was looking for real quick, but something like this:

    New Testing Equipment-image.jpg

  7. #7
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    That's a good idea, ill try to find something too, thanks.

    Well outta propane for garage heat so ill be doing final testing of the set up tonight to make sure everything is good to go.

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    OK testing going good. Airflow on the cooling tube is about 6.5mph, little over 9 on the new wind tunnel. have some tests to do on how well its cools, first light head attempt was Xeccon Z10 (Z11 is being "worked on" atm) and its responding same as it did on the old wind tunnel. Guess 6.5mph isnt going to cut it any way I try it for current "stock" form of those heads. Well see how the 3A yinding does.


    Update: Ran the yinding through on a 30 minute test. Got results I didnt expect and if I wasnt seeing it I wouldnt believe it. Blue yinding is set up on KD2 driver, modded to 3A, dual XP-L HI V2 3C emitters on DTP copper Noctigons. Vancbikers LowPro gopro mount adapter. For the first part of the test it did exactly what i expected. Slowly dropped lumen output as things heated up. Stabilized at 1892 lumens (from 1966 at 30 seconds). just hovered at or slightly above 1892 for a while. Then pack voltage dropped below 7.35V... current draw started to increase slowly, but so did output. 2032 lumens when I stopped checking to try another, more charged pack. Which light went right back to 1892. PUt the previous pack back on, and dropped to 1892 at first then started climbing back up as current draw from the pack increased.

    TEst proved ONE THING, XP-L emitters are the future of bike lights. My yinding on XM-L2 couldnt handle the heat well at all at 3A unless air speed was at or above 10mph. now at 6.5 mph, its thermally stable, awesome output, never stepping down or loosing the output from getting good and hot.

    Cant wait to get the graphing sorted out so I can start running comparisons. Nothing like "tested and true" proof to what some of us have been saying for a while now.

  9. #9
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    Quote Originally Posted by andychrist View Post
    Think if you print out the LED color graph, then what ever tint square matches the illuminating emitter will disappear into a white background, if that makes any sense. Couldn't find the one I was looking for real quick, but something like this:
    One of method used to determine K of the light is using good picture camera with manual White Balance settings. You are adjusting WB to the K where the piece of paper looks completly white. This will tell you at least the range or the class to which the light belongs.

    Anyway, very good job Tigris!!! Now you are becoming Led light scientist

    PS. You have also proved you need stable and adjustable power supply to get consistent results.

  10. #10
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    Thanks ledoman, im trying!!!

    My power supply is still battery pack for the lights . My adjustability was the pack voltage, wasnt fully charged. I actually do get consistent numbers as long as im consistent on pack voltage. Be ALOT easier with an adjustable power supply but those things arent cheap.

  11. #11
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    Okay another stupid question: Would it be possible for you to calculate the CRI too somehow? Can't imagine how that's done.

  12. #12
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    Lmao, hell no, I just checked I to figuring that out, um NO. There's A LOT to that (really involved in sorting it all out) and this stuff costs me enough valuable riding time . There is a standardized color chart that's part of the process which can show if CRI is high or low, basically what I do shining lights in my kids toys outside.

  13. #13
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    Ok I found a chart for cri, need to find one for color temp like it. Though I think the one you show if I have it printed on poster board would work.

  14. #14
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    Great job Tigris99! Love it! One thing though - I'm using that same cheap Lux Meter and not getting accurate results. It's on my wishlist to buy the "good one". Yours seems to be working well though.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

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    U have to calibrate to ur set up is a lot of it. We don't have the accurate spheres with the special coatings, so have to adjust the "surface area" in the equation till you start getting lumens you should. A good meter will be off too.

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    I'm talking straight lux readings to generate kcd #'s (throw distance). My modded Courui flashlight should be up over 100kcd, but with my meter I'm only calculating around 50kcd.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  17. #17
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    That would be hard to do with the way the sensor is on these as if I understand correctly, its based off lux at a given distance but hard to hit the little sensor on this thing. But hey, its cheap and works good in the sphere (though I am curious as to what a better one will read). Still trying to sort out HOW to figure that out directly since it cant be done with a sphere to my understanding. That whole trying to do it at a distance thing is difficult at best with optics because of the beam spread.

  18. #18
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    Ok here's my runtime output test. Used wiz20 as its the simplest to deal with (and easily consistent).

    Wish my camera had longer time lapse gap than 60 seconds. But i am going to condense time increments cause almost 3hrs is a bit too much to type in each reading from every 60 second data sample picture.


  19. #19
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    OK heres a cleaned up version, now that I know how to do it, have them up on google docs for everyone to see as I get lights ran through and added. Might have an insane amount of free time this week if this storm hits us the way they are afraid it might.

    https://docs.google.com/spreadsheets...NSU/edit#gid=0

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    Ok, I'm looking into / pursuing the "round hollow foam sphere" idea. What size is your foam ball? I've had a really tough time finding even 12 inch diameter for a reasonable price and yours looks much larger than 12 inches. You say "80mm" in the O.P., but that ain't no 80mm diameter sphere! 80cm? 12 inches should work for my purposes, but if I can go larger without a huge jump in price I would. Care to share a link where you purchased?

    For reference, here's the BLF thread I am following proving the concept: Integrating sphere #4 (the fast and cheap one) | BudgetLightForum.com

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  21. #21
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    Hobby lobby or amazon. 12" half foam balls, buy 2.

  22. #22
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    Ok, I'm getting 12" half balls (locally from Jo-Ann Fabrics). Your balls sure look bigger though . . . wait a minute, that didn't come out right .

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  23. #23
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    That's cause their on a pedestal, so big need something to hold them up

  24. #24
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    Finally got my DIY integrating sphere completed. Not as fancy as tigs, but it'll do the job. Now I just have to calibrate my measurements which may be tough as I don't have many (if any) reliably spec'd lights to calibrate to and check against. I did borrow a Fenix HL55 headlamp to start with which has been tested (though the test was on a pre-production unit) and verified.

    Some pics:

    Final Product:


    In Use, prior to attaching to my base (measuring my Convoy S2 EDC light):


    -Garry
    (Pics aren't loading for me at the moment. Hopefully they will load soon.)
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  25. #25
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    Just FYI, any light you can see outside of the sphere is lost lux.

    Making the outside black is East and cheap. Simple black acrylic craft paint and the sponge brushes from Walmart. Think I paid a total of $5-6 but I also got flat white to coat the inside. Did best I could to keep the beam pattern from effecting the measurements and it worked well.

    My other "fancy stuff" was mostly things I had. Had to buy a few PVC joints and the sheet of plastic to cut the adapter plates out of.

    I want to actually make my input hole slightly larger and then get another couple half spheres to cut adapters from. So they maintain the sphere shape internally. Got the idea from the pics of the MTBR review sphere.

    Speaking of his sphere, I see now why certain lights do better than others, his fan is pointed to move air across the case laterally, not in the direction of air flow during real world use. FAIL! That's why mine is set up the way it is. Still needs tweaking but works pretty well.

    Sent from my XT1565 using Tapatalk

  26. #26
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    Well over at BLF it was decided painting the inside and painting/covering the outside yielded insignificant differences. djozz compared the results from this simple one to his more complex one and results were within 10% (which isnt that much really). I did sand the inside with 100 grit sandpaper which was recommended after his 10% accuracy statement. I'd be afraid of the black paint permeating the foam.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  27. #27
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    It doesn't/can't. Acrylic craft paint just seals up the outside. Nothing in it attacks the foam and the furthest I've seen is make is into the open cells on the very surface. When I added the cooling fan set up I had to cut more of the external area to create the ducts for air intake. Paint didn't make it past .01-.1mm from the surface.

    I can see painting the inside having little to no effect. Even getting high readings. Which is why I sanded it lightly afterwards, just to be safe.

    You know me, I'm picky, so 10% is a big difference . But too I do a lot of reviews and all that so I don't want to under rate a light. But that 10% could correct excessively high readings before calibration. That's the one hiccup I was running into.

    Found how to adjust on candlepower. Using a flat percentage doesn't work. You have to change the sphere surface area in the equation to calibrate. My sheet on Google if you haven't looked in a while, all the readings have changed. I realized my calibration was off but changing lux readings by a percentage was screwing everything up. The X2 is what made me realize something wasn't right. Known numbers right on some lights, way low on others after I used percentage to correct x2 reading.

    Did some digging, found by reducing the sphere size in the formula suddenly everything fell into place.

    Also you can calibrate your sphere using sunlight or a good quality LED light bulb. You'll be able to get within 5% which is what our cheap lux meters are rated at. I had no clear, sunny days for a while so that was out, trying to calibrate with an LED light bulb was proving insanely difficult due to trying to minimize the size of the hole in the sphere.

    Your way is much easier to work with (some times I think I'm over thinking/being too [email protected] lol)

    Sent from my XT1565 using Tapatalk

  28. #28
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    Changing sphere surface area? How? I don't get it. And I've not yet seen any formulas. Got links?

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  29. #29
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    Lumens = lux * surface area

    SA= 4πr(2). 4πr(squared). Reduce the radius of the sphere in this formula if you realize your getting high readings.

    Can't get lumen output of a light without the formula. It's just lux without it. Unless of course you have a meter that will do it for you after you enter in the sphere surface area into it.

    Here's a website calculator:

    http://www.rapidtables.com/calc/ligh...calculator.htm


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  30. #30
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    I see references to the method you speak of, but I believe I see where many users are simply doing a calibration to lights with known verified lumen ratings. They then determine their "multiplier" to use with their lux reading to obtain that lumen number. They then test against other known lights (the more the better, including low lumen and high lumen lights) to make sure their multiplier works within reason to the verified lumen ratings of those lights too. This method has been tested and verified by many. My biggest problem is that I don't have enough lights of "known/verified" lumen ratings.

    Now the issue with the sphere not being painted to block light from escaping, I'll have to dig into that. I will say that I did some testing last night, setting up my sphere directly under a 20w CFL ceiling light (typical cheap lampholder with bare bulb pointing downward). My luxmeter while attached to the sphere was only reading 1.4 lux - a pretty insignificant amount of ambient light coming in (and that was without my hand and a flashlight in the way of the opening). I then took readings on my EDC Convoy S2 which as expected pretty matched identical to the readings I took in complete darkness. I then wrapped the sphere with a black towel the best I could (to try and mimic painting the sphere, though I understand it's not the same thing) and took readings again. Those results were just ever so slightly higher (and "high" mode showed a more significant increase than low or medium), however I doubt they would make that much difference in the lumen calculation (I haven't ran any calculations yet). I would also need to re-calibrate my sphere with the Fenix headlamp again since I only took readings on it without the towel. My hunch is kinda what I think you were pointing out, that you're just drilling down from say 10% accuracy to 5% accuracy level. I think the bigger issue for error for me is where I am holding the face of the light during the readings as the readings can change drastically as you move the light in and out of the hole. I'm trying my best to keep the face of the light even with the inner circumference of the sphere (i.e. the bottom of the hole), though it's tough when you're trying to turn off your room lighting, start a stopwatch (to get a reading at 30 seconds), and catch the initial lux reading! I almost need a glass shelf to rest the light on. (I do like your idea of brackets to hold the light in place and just might do something similar.)

    I did verify my hunch that my HS1010 luxmeter was giving way too low of results (the pic they're in direct sunlight and both on the "x100" setting.



    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  31. #31
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    Garry, you realize that your "multiplier" is the same thing right??? Sphere surface area is a set number, so EXACT same thing as doing a "multiplier".

    Lumens = lux x surface area

    Lumens = lux x multiplier

    For me surface area or " multiplier" is 0.0261

    That's why their way works just fine because it's the same thing, just the number is acquired a different way.

    The whole room light thing the other half of the reason for what I did, keep the ambient light out.

    It doesn't surprise me that these cheap ones read low but the multiplier fixed that for sphere use.

    BTW the "surface area" way of doing it won't have the lumens reading correctly. It is how you do it for a lab spheres but not for us. You still have to change the number accordingly to get the correct lumen numbers. Which is probably why it was simplified to just doing the "multiplier" instead of trying to figure out the surface area matter.

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  32. #32
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    Quote Originally Posted by tigris99 View Post
    Garry, you realize that your "multiplier" is the same thing right??? Sphere surface area is a set number, so EXACT same thing as doing a "multiplier". . .
    That's why their way works just fine because it's the same thing, just the number is acquired a different way.
    Exactly, I was just saying doing it "this other way" has been tested and verified as valid.

    Quote Originally Posted by tigris99 View Post
    The whole room light thing the other half of the reason for what I did, keep the ambient light out.
    And I showed this is pretty insignificant, unless you are measuring moonlight levels. (So long as you're not taking readings outdoors in bright sunlight or with HID headlights pointing at the sphere. )


    Quote Originally Posted by tigris99 View Post
    It doesn't surprise me that these cheap ones read low but the multiplier fixed that for sphere use.
    I assumed so long as you "calibrate" to that meter you would probably be okay using it. The original reason I put my old meter on the shelf was because of my throw numbers calculating way too low and there was no way for me to fix that without getting a better meter.

    Quote Originally Posted by tigris99 View Post
    BTW the "surface area" way of doing it won't have the lumens reading correctly. It is how you do it for a lab spheres but not for us. You still have to change the number accordingly to get the correct lumen numbers. Which is probably why it was simplified to just doing the "multiplier" instead of trying to figure out the surface area matter.
    I tried to take some "sun" readings yesterday (note that I did NOT research on any methodology to use beforehand - just tried to run outside and grab some data) and it went horrible! My readings would jump all over the place. I then tried to aim the entry hole for the highest reading but couldn't keep the sphere locked in that position esp. when trying to remove the meter to take the direct reading at the entry hole - which doesn't work anyway because I couldn't get the sensor down inside even with the bottom of the hole. It was frustrating and I gave up. I have read where in place of using the sun you can use a "thrower" flashlight directed at the entry hole but I wasn't going to bother with that.

    I'll have to run some calculations soon and will come back with my results. I might even get in touch with you to see if you're interested in swapping some lights back & forth to see if I can reproduce readings you get within reason.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

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    For sun use its difficult but the way I understood it is the meter is in its normal hole then point the entry hole at the sun. Basically an "assembled" sphere just pointing entry hole at the sun. I could be wrong though, I should have saved a link to the threads on candlepower I found.

    Sent from my XT1565 using Tapatalk

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    I'll post here just because it sort of fits. I ran some lumen calcs on some of my lights in my DIY integrating sphere. I feel fairly good about my numbers, though they need verified through the use of other "calibration lights" (I'm in process on that). Please do NOT take these numbers as solid figures! Also, the spreadsheet shows lumens out to one decimal place. They should probably be rounded to at least the nearest 10 lumens. Also remember that ANSI FL-1 standard is the value after 30 seconds.

    (CLICK TO ENLARGE)



    I like that my BT40S came in right about where I expected it. I had conservatively estimated output on Turbo to be 2000 lumens.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  35. #35
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    Quote Originally Posted by tigris99 View Post
    U have to calibrate to ur set up is a lot of it. We don't have the accurate spheres with the special coatings, so have to adjust the "surface area" in the equation till you start getting lumens you should. A good meter will be off too.
    Not sure if you have seen a professional sphere. Two important things I haven't seem mentioned here.
    1. No direct light should hit the meter. It should all be reflected off the sphere. A baffle is placed inside to put the meter is a shadow from the direct source.
    2. A pro sphere/meter is calibrated before every run with a calibrated reference light source. The ones I've seen are a incandescent bulb driven with a precise voltage. From your reading from the reference source you calculate a multiplier. If you use a quality light that has been tested (like an X1) you could calibrate reasonably close.

    Also, an adapter is made for each light tested so it's a tight fit with the opening. Shining a light into a big hole allows light to escape the sphere.
    Jim Harger
    Action LED Lights
    www.action-led-lights.com

  36. #36
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    Those are all things mentioned in the BLF thread I based my round Polystyrene DIY sphere on. My meter is placed so as not to receive any direct light (it's next to the opening, so only an extremely floody light source would affect it). The meter's sensor is also outside the foam and not exposed inside. Exposed inside would definitely require a baffle.

    The calibration "reference light" was also discussed (more discussion of that over in this BLF thread though). This reference calibration light seems to only be needed if you are really looking to drill down your accuracy. What I do try to do (& recommend) is using a "reference light", a light with well regulated output to do a check measurement prior to measuring other lights. So I take a previously measured light with a regulated Nanjg driver (low/medium modes, since high may drop due to heat or voltage sag). If my check measurement is darn close to what I've measured in the past (i.e. the day I did my initial calibration - which by the way was with a light I do not own but borrowed) then I know my subsequent measurements should be good.

    In regards to the idea of the "adapter rings at the entrance hole", BLF member djozz has stated this here:

    Quote Originally Posted by djozz
    The widespread misconception is that you need to keep as much light inside the sphere as you can for the best accuracy. Keeping the light inside helps the amount of integration but with a well-build sphere that is not your problem, if your total of holes is under 5% of the inner surface (this is a rule-of-thumb number for a very good reflecting inner surface, our polystyrene surface is worse than that so I keep them under 2%) the integration is good enough to worry about other, bigger flaws.

    What is really needed is not maximising the reflectivity at all times, but keeping the reflectivity constant. Then your multiplier is fixed. Wether you need the white stencil (or not, or any shade of grey) around a flashlight can only determined by measuring the reflectivity.

    For improving accuracy for this type of sphere, you can either minimise reflectivity variance caused by entrance hole effects by reducing the hole/inner surface ratio (i.e. small hole in large sphere), or you can measure the specific sphere reflectivity for each to be measured light source before doing the actual light measurement (using a constant output light source elsewhere in the sphere) and then adjust the multiplier accordingly.
    The real problem (and hence need for the reference light) is that your reflective surface area changes depending on the size of the light you place at the opening (think glass lens of a large light compares to the lens of a keychain light at the opening). I measured how much this is affected in my sphere posted here (see YouTube videos there) using a keychain light and saw lux readings increase from 2.57% with a 3AAA light placed in the hole to 12.57% with a very large Courui light (+/-75mm head diameter - nearly the full width of my sphere's entrance hole). My calibration light (a Fenix HL55 headlamp) is a rather medium sized light placed in my sphere's entrance, so I came to the conclusion not to bother with adding a "calibration light". Yes smaller lights and larger lights will be known to be "off", but should be within a reasonable amount. I'm not looking to measure within 1 lumen tolerance. Most of my lights will be of the "medium sized" variety.

    I'm in process of swapping & measuring lights with another BLF member who uses a homemade but verified "Lumens measuring device" and am anxious to see how we compare.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  37. #37
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    Jim,

    If you look at the pictures I do have adapters I make to fit a couple different lights each. May loose a small amount of light since each doesn't fit tight but being these are DIY units, they are rather close.

    As for calibration source, that's another DIY thing so we work with what we have basically. Trying to do a proper calibration source is difficult without funds to purchase one.

    And thanks for pointing out the baffle to keep light from directly hitting the sensor. I though I had mentioned it in my original but I may not have. I do have a baffle installed. Was done before sphere was sealed and painted (externally).

    Thanks for the info.

    Sent from my XT1565 using Tapatalk

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