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Inexpensive LUX meter from China to measure your bike lamp's output
Inexpensive LUX meter from China to measure your bike lamp's output. Stumbled across this while I was looking for something else. No recommendation, but I remembered you guys were discussing lux ratings not too long ago.
https://www.aliexpress.com/store/pro...4b9c46a0WLmNTx Andre Jute Always helpful |
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Inexpensive LUX meter from China to measure your bike lamp's output
On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute
wrote: Inexpensive LUX meter from China to measure your bike lamp's output. Stumbled across this while I was looking for something else. No recommendation, but I remembered you guys were discussing lux ratings not too long ago. https://www.aliexpress.com/store/pro...4b9c46a0WLmNTx Andre Jute Always helpful Sigh. I see that you haven't been reading my rants. That's the exact model that I've recommended in at least three of my previous rants on the topic. Also available on eBay and Amazon. https://www.ebay.com/itm/222318701790 or search for "lux meter". Also from several revious rants, if you draw a 1.13meter (44.5inch) diameter circle on the wall, and shine your bicycle head light or flashlight on the wall until it fills the circle, the lux meter will read directly in lumens. It works because the area of the circle is 1 square-meter and: 1 lux = 1 lumen/sq-meter If you light produces a non-circular spot on the wall or an uneven pattern, just guess(tm) until you have a spot that looks roughly like 1 square-meter. No warranty for accuracy expressed or implied. Lux Sit (Let let there be light). -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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Inexpensive LUX meter from China to measure your bike lamp's output
On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote:
On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute wrote: Sigh. I see that you haven't been reading my rants. That's the exact model that I've recommended in at least three of my previous rants on the topic. Also available on eBay and Amazon. https://www.ebay.com/itm/222318701790 or search for "lux meter". The more sources the better, then. Andre Jute I like your DIY calibration test, though. |
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Inexpensive LUX meter from China to measure your bike lamp's output
On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute
wrote: On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote: On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute wrote: Sigh. I see that you haven't been reading my rants. That's the exact model that I've recommended in at least three of my previous rants on the topic. Also available on eBay and Amazon. https://www.ebay.com/itm/222318701790 or search for "lux meter". The more sources the better, then. I have 2 other Lux meters. Both have removable sensor "pucks" which allegedly make measurements easier. I've compared readings between the three meters and find that they are all fairly close to each other. I don't have a calibrated source, so I can't determine their accuracy. The UNI-T UT383 above is the most useful because it's the only one that has a peak reading feature. I mark the diameter of my one square meter circle on the wall, turn on the test flashlight or headlight, and walk towards the wall until the spot has the same diameter. I then turn off the light, and the highest reading remains on the display. Very handy for doing measurements without an assistant. If you want better accuracy, measure the hot spot in the center and the brightness at the edges. I usually give it 33% above the edge value, although 50% is probably close enough. I like your DIY calibration test, though. You might want to measure your various lights and headlights and see how they compare with the published specs. If enough people do that, maybe we can see an end to inflated lumens specs. I measured about 15 assorted lights and flashlights, but nobody seemed interested. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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Inexpensive LUX meter from China to measure your bikelamp's output
Jeff Liebermann wrote:
On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute wrote: On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote: On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute wrote: Sigh. I see that you haven't been reading my rants. That's the exact model that I've recommended in at least three of my previous rants on the topic. Also available on eBay and Amazon. https://www.ebay.com/itm/222318701790 or search for "lux meter". The more sources the better, then. I have 2 other Lux meters. Both have removable sensor "pucks" which allegedly make measurements easier. I've compared readings between the three meters and find that they are all fairly close to each other. I don't have a calibrated source, so I can't determine their accuracy. The UNI-T UT383 above is the most useful because it's the only one that has a peak reading feature. I mark the diameter of my one square meter circle on the wall, turn on the test flashlight or headlight, and walk towards the wall until the spot has the same diameter. I then turn off the light, and the highest reading remains on the display. Very handy for doing measurements without an assistant. If you want better accuracy, measure the hot spot in the center and the brightness at the edges. I usually give it 33% above the edge value, although 50% is probably close enough. I like your DIY calibration test, though. You might want to measure your various lights and headlights and see how they compare with the published specs. If enough people do that, maybe we can see an end to inflated lumens specs. I measured about 15 assorted lights and flashlights, but nobody seemed interested. Both lux and Lumens stated are a guide really, or to put it another way, I’ve noticed more difference from the beam shape than the claimed Lux/lumens which makes sense since Lux is for bikes at least measured at the 10 meter mark, and Lumens is generally what ever the led will can produce. What neither will tell you is how they light the trail/road, or to put it another way seeing the light working is a far better test than lumen/Lux stats. And to be honest it’s best to see it as you where rather than seeing screen shots as beam shots are difficult if not impossible to do fairly since human eye and cameras do differ in this regard so some lights look much better or worse in beamshots. Roger Merriman |
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Inexpensive LUX meter from China to measure your bike lamp's output
On Wednesday, February 21, 2018 at 10:16:43 PM UTC, Roger Merriman wrote:
Jeff Liebermann wrote: On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute wrote: On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote: On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute wrote: Sigh. I see that you haven't been reading my rants. That's the exact model that I've recommended in at least three of my previous rants on the topic. Also available on eBay and Amazon. https://www.ebay.com/itm/222318701790 or search for "lux meter". The more sources the better, then. I have 2 other Lux meters. Both have removable sensor "pucks" which allegedly make measurements easier. I've compared readings between the three meters and find that they are all fairly close to each other. I don't have a calibrated source, so I can't determine their accuracy. The UNI-T UT383 above is the most useful because it's the only one that has a peak reading feature. I mark the diameter of my one square meter circle on the wall, turn on the test flashlight or headlight, and walk towards the wall until the spot has the same diameter. I then turn off the light, and the highest reading remains on the display. Very handy for doing measurements without an assistant. If you want better accuracy, measure the hot spot in the center and the brightness at the edges. I usually give it 33% above the edge value, although 50% is probably close enough. I like your DIY calibration test, though. You might want to measure your various lights and headlights and see how they compare with the published specs. If enough people do that, maybe we can see an end to inflated lumens specs. I measured about 15 assorted lights and flashlights, but nobody seemed interested. Both lux and Lumens stated are a guide really, or to put it another way, I’ve noticed more difference from the beam shape than the claimed Lux/lumens which makes sense since Lux is for bikes at least measured at the 10 meter mark, and Lumens is generally what ever the led will can produce. What neither will tell you is how they light the trail/road, or to put it another way seeing the light working is a far better test than lumen/Lux stats. And to be honest it’s best to see it as you where rather than seeing screen shots as beam shots are difficult if not impossible to do fairly since human eye and cameras do differ in this regard so some lights look much better or worse in beamshots. Roger Merriman It seems as if we're all largely in agreement, Roger, even Barry; these mickey mouse disagreements that people blow up quite inordinately to inflate their egos are about angels dancing on a pin, most of the time. That's where BUMM lamps score, in practice, despite their sometimes distressing shortcomings. They built the first adequate hub dynamo lamp, the first series Cyo. It has approximately the same output and spread as 6V VW Beetle lamp offered in 1960. However, BUMM, corporately, has another peculiarity. They build a good first series, and then screw up several subsequent series with "improvements" that aren't, and then maybe make a good one again in that series (the latest Cyo is apparently an improvement over the first series) but more often just make a new-concept lamp, where the degeneration of the series starts all over again. This makes it expensive in lamps given away or lying idle to try out BUMM lamps until you find a good one. And even their good ones are compromised by Geman legislation which a) forbids blinkies, b) limits the output of the hub dynamo plus c) BUMM's deplorable (but very common) bias towards roadies in shaping the beam of their lamps. Andre Jute Fair to a fault |
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Inexpensive LUX meter from China to measure your bike lamp's output
On Wednesday, February 21, 2018 at 4:14:21 PM UTC, Jeff Liebermann wrote:
On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute wrote: On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote: On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute wrote: Sigh. I see that you haven't been reading my rants. That's the exact model that I've recommended in at least three of my previous rants on the topic. Also available on eBay and Amazon. https://www.ebay.com/itm/222318701790 or search for "lux meter". The more sources the better, then. I have 2 other Lux meters. Both have removable sensor "pucks" which allegedly make measurements easier. I've compared readings between the three meters and find that they are all fairly close to each other. I don't have a calibrated source, so I can't determine their accuracy. The UNI-T UT383 above is the most useful because it's the only one that has a peak reading feature. I mark the diameter of my one square meter circle on the wall, turn on the test flashlight or headlight, and walk towards the wall until the spot has the same diameter. I then turn off the light, and the highest reading remains on the display. Very handy for doing measurements without an assistant. If you want better accuracy, measure the hot spot in the center and the brightness at the edges. I usually give it 33% above the edge value, although 50% is probably close enough. I like your DIY calibration test, though. You might want to measure your various lights and headlights and see how they compare with the published specs. If enough people do that, maybe we can see an end to inflated lumens specs. I measured about 15 assorted lights and flashlights, but nobody seemed interested. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 Even at such an attractive price, I'm not buying the meter, Jeff. For health reasons, I no longer go for those middle watches of the night rides, as no one will go with me and it's stupid for me to ride alone on totally empty lanes. So I have nothing to measure for. In any event, by subjective measurement a la Roger's post, I judge I already have what on balance I consider BUMM's best lamp, the first series Cyo R (I also have reflectorless version but it isn't as good in lanes as the R, and I have the Fly-E with supposedly the same optics but with a very nasty hotspot), so I'm not even in the market for new lamps. Andre Jute It's a dull life if you can't even think of a tool you want |
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Inexpensive LUX meter from China to measure your bike lamp'soutput
On 22/02/18 01:52, Andre Jute wrote:
snip In any event, by subjective measurement a la Roger's post, I judge I already have what on balance I consider BUMM's best lamp, the first series Cyo R (I also have reflectorless version but it isn't as good in lanes as the R, and I have the Fly-E with supposedly the same optics but with a very nasty hotspot), so I'm not even in the market for new lamps. Three of those dies before I gave up on them, all inside 18 months each. Do you go out in the rain much? |
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Inexpensive LUX meter from China to measure your bike lamp's output
On Wed, 21 Feb 2018 16:52:57 -0800 (PST), Andre Jute
wrote: Even at such an attractive price, I'm not buying the meter, Jeff. I consider it beneficial if those recommending a product would also have some experience using it. For health reasons, I no longer go for those middle watches of the night rides, as no one will go with me and it's stupid for me to ride alone on totally empty lanes. So I have nothing to measure for. I have a similar problem. I don't ride at night. Too dangerous around here and my night vision is slowly deteriorating. However, this has not stopped me from commenting on the topic and testing various lights. In any event, by subjective measurement a la Roger's post, I judge I already have what on balance I consider BUMM's best lamp, the first series Cyo R (I also have reflectorless version but it isn't as good in lanes as the R, and I have the Fly-E with supposedly the same optics but with a very nasty hotspot), so I'm not even in the market for new lamps. Et tu Jute? I was under the delusion that we were discussing instruments and methods of measuring light output and not a review of available products. Oddly, every time (and I do mean every time) I bring up the subject of light measurement, the discussion immediately drifts away from measurements and gets mired on the mud flats of anecdotal experience and subjective "calculation". It would seem that the participants greatly fear making measurements and the assignment of numbers to their favored bicycle headlight, as if this would somehow diminish the value of their illuminating experience. I wonder if it is even possible to discuss light measurements without the apparently incurable product endorsements, which incidentally is only slightly less prevalent in the flashlight forums. Andre Jute It's a dull life if you can't even think of a tool you want I only need one tool. Anything within reach can be used as a hammer. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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Inexpensive LUX meter from China to measure your bike lamp'soutput
On 2/21/2018 12:21 AM, Jeff Liebermann wrote:
Also from several revious rants, if you draw a 1.13meter (44.5inch) diameter circle on the wall, and shine your bicycle head light or flashlight on the wall until it fills the circle, the lux meter will read directly in lumens. It works because the area of the circle is 1 square-meter and: 1 lux = 1 lumen/sq-meter If you light produces a non-circular spot on the wall or an uneven pattern, just guess(tm) until you have a spot that looks roughly like 1 square-meter. No warranty for accuracy expressed or implied. You need to build an integrating sphere. http://forums.mtbr.com/lights-diy-do-yourself/diy-integrated-sphere-780122.html Or buy one. http://www.pro-lite.co.uk/File/general_purpose_spheres.php |
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