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Inexpensive LUX meter from China to measure your bike lamp's output



 
 
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  #31  
Old February 25th 18, 03:52 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Inexpensive LUX meter from China to measure your bike lamp'soutput

On 2/25/2018 5:32 AM, Sepp Ruf wrote:
Frank Krygowski wrote:
On February 24, 2018 at 10:10:41 PM UTC-5, Jeff Liebermann wrote:

Opinions vary:
- Frank wants brightness limited to avoid blinding oncoming motorists.


Well, that's an oversimplification at best. I don't want to blind anyone,
and I don't want other cyclists blinding me, which has happened many times.
But that calls for lower intensity only above the horizon. Lumens on the road
shouldn't cause that problem. Assuming, that is, they are properly spread. I
think "hot spots" tend to stop down one's pupils and decrease night vision.

Mostly, I object to the claims that something over 200 lumens is necessary.
I've done too much pleasant riding with B&M lights putting out less than 150
properly focused lumens. I think the cries for more are, at best, ill-informed.

However, it recently occurred to me that at this time of year, there might be
some utility to mega-lumen lights. If they were bright enough to melt the snow,
or (on a night like this) to dry the puddled roads ahead of the cyclist,
I might be convinced to use one. We're almost there.


If the current crop of kickstarted U.S. bicycle lighting guys weren't
muscle-car tuners unsafely operating flasherless bicycles inside Kentucky
caves, with their trail beams set quite low, I'd recommend you try swapping
your non-selling Oculoss for a review sample of Outbound Lighting's Focal
Series Road Edition light:
https://www.outboundlighting.com/product/focal-series-road-edition


I am glad to see more people recognizing that round beams are not optimum.


--
- Frank Krygowski
Ads
  #32  
Old February 25th 18, 04:59 PM posted to rec.bicycles.tech
SMS
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Posts: 9,477
Default Inexpensive LUX meter from China to measure your bike lamp'soutput

On 2/24/2018 7:10 PM, Jeff Liebermann wrote:

Opinions vary:
- Frank wants brightness limited to avoid blinding oncoming motorists.
- SMS wants some upwards spill to help see overhanging branches.
- You seem to want (not sure) more beamwidth to help see the roadside.
- NASA wants even lighting and no hot spot so that press release
photos look good.
- Barry wants only the forward facing area to be considered (beam
lumens), discarding the dim spillage as useless light.
- I want megalumens so I can set fire to the riders clothes ahead of
me. I also want megalumens because my principle use is "be seen"
lighting, which means I want to get the attention of motorists.


That's not an accurate collection:

- Frank's main concern is that the light work off a dynamo. All his
other statements are rationalizations of why it is not necessary to
illuminate anything other than the pavement immediately in front of a
rather slow-moving rider. He understands, but does not want to admit,
the importance of proper optics on LED lights in order to illuminate not
only the patch of pavement directly in front of the tire.

- I want both side spill and upward spill. But of course you can do this
without blinding oncoming motorists, which is a red-herring anyway since
on even a two lane road, with the cyclist on the right (or on the left
in countries where they drive on the wrong side of the road), a motorist
coming the other way will not be blinded. The real concern is that on a
narrow MUP that oncoming cyclists not be blinded.

- More beam width is also a side effect of a proper beam shape.

- Barry's emphasis on NASA is unhelpful in marketing bicycle lights. His
lights do have some real advantages in terms of optics and batteries,
and if they were priced at $100 and $200 I think he'd be selling a lot
more of them. It's really hard to work with bicycle shops that demand
Keystone margins, and even harder if you have to go through distribution.

- Your desire to set fire to the clothes of riders in front of you will
not be achieved by LED lights. You could use a flame thrower, but to
achieve sufficient range would require a very heavy and cumbersome
system. You might look into laser modules, i.e.
https://www.amazon.com/dp/B071HB9LX5. Since you'd not need it to run
for long periods of time, you could run it off of a 4S Li-Ion battery pack.

- Jay's main concern is that whatever light he buy be on the bargain
table at one of Portland's famous bicycle shops.

- Joerg's main concern is that the light and battery can pass his
vibration tests.
  #33  
Old February 25th 18, 07:49 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 4,018
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Sun, 25 Feb 2018 07:59:58 -0800, sms
wrote:

On 2/24/2018 7:10 PM, Jeff Liebermann wrote:

Opinions vary:
- Frank wants brightness limited to avoid blinding oncoming motorists.
- SMS wants some upwards spill to help see overhanging branches.
- You seem to want (not sure) more beamwidth to help see the roadside.
- NASA wants even lighting and no hot spot so that press release
photos look good.
- Barry wants only the forward facing area to be considered (beam
lumens), discarding the dim spillage as useless light.
- I want megalumens so I can set fire to the riders clothes ahead of
me. I also want megalumens because my principle use is "be seen"
lighting, which means I want to get the attention of motorists.


That's not an accurate collection:


True. In the same way vendors try to condense the essence of bicycle
lighting into one number (lumens), I tried to describe the purchase
requirements in one line per rider. Half way through, I gave up and
added more lines. More is always easy. Less is not so easy.

- Barry's emphasis on NASA is unhelpful in marketing bicycle lights.


The problem is word association. When I think of NASA, I think of
expensive cost overruns, the Challenger disaster, inept Hubble
management, and some not so well know NASA screwups.

- Your desire to set fire to the clothes of riders in front of you will
not be achieved by LED lights. You could use a flame thrower, but to
achieve sufficient range would require a very heavy and cumbersome
system. You might look into laser modules, i.e.
https://www.amazon.com/dp/B071HB9LX5. Since you'd not need it to run
for long periods of time, you could run it off of a 4S Li-Ion battery pack.


Nice, but only 15 watts. This vendor claims they can supply 30 watts
in a much smaller form factor:
http://www.everyonetobuy.com/super-strong-30000mw-blue-laser-pointer-shop.html
It might not set the obstructing riders clothes on fire, but it will
certainly get their attention. Thanks for the idea and link.

- Jay's main concern is that whatever light he buy be on the bargain
table at one of Portland's famous bicycle shops.


Full disclosure. All but one of my various bicycles came from
dumpster diving, garage sales, or thrift shops. Availability from
discount houses and possibly counterfeiters would be nice.

Thanks for the additional topic drift.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #34  
Old February 25th 18, 08:43 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Inexpensive LUX meter from China to measure your bike lamp'soutput

On 2/25/2018 10:59 AM, sms wrote:

- Frank's main concern is that the light work off a dynamo. All his
other statements are rationalizations of why it is not necessary to
illuminate anything other than the pavement immediately in front of a
rather slow-moving rider. He understands, but does not want to admit,
the importance of proper optics on LED lights in order to illuminate not
only the patch of pavement directly in front of the tire.


It's true that I greatly prefer dynamo lights, so I don't have to fuss
about recharging or replacing batteries - SMS recently noted that even
rechargeable batteries may soon need replacement. I want my bikes to be
always ready to properly light the way for safe riding in the dark.

That means much more than "the patch of pavement directly in front of
the tire." I have at least two B&M dynamo headlights that show a stop
sign up to 1/4 mile away. They light the roadway far enough ahead for
riding well over 20 mph. In my experience, it was the LED flashlights
SMS advertised that were limited to a patch of pavement.

- I want both side spill and upward spill. But of course you can do this
without blinding oncoming motorists, which is a red-herring anyway since
on even a two lane road, with the cyclist on the right (or on the left
in countries where they drive on the wrong side of the road), a motorist
coming the other way will not be blinded. The real concern is that on a
narrow MUP that oncoming cyclists not be blinded.


I have been blinded while riding at night more than once by oncoming
*kilo-lumen cyclists on full-width two lane roads. I've had it on bike
trails, too, even though I don't spend much time on bike trails.

In fact, I even had trouble once with a rider's kilo-lumen light while I
was driving in daytime. It was a female cyclist on a rural highway. She
was apparently a victim of extreme "fear from the rear." She had a
hugely bright headlight mounted on her bike's rear rack, facing
backward. I changed lanes to pass, as I would have anyway; but I had to
shield my eyes as I did so.

White lights facing rear on bicycles violate state law. Not that it
matters to people like that.

(* I guess I should use kilo-lumen instead of mega-lumen. The latter
probably won't be available for a year or two.)

--
- Frank Krygowski
  #35  
Old February 25th 18, 09:35 PM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Sunday, February 25, 2018 at 8:00:01 AM UTC-8, sms wrote:
On 2/24/2018 7:10 PM, Jeff Liebermann wrote:

Opinions vary:
- Frank wants brightness limited to avoid blinding oncoming motorists.
- SMS wants some upwards spill to help see overhanging branches.
- You seem to want (not sure) more beamwidth to help see the roadside.
- NASA wants even lighting and no hot spot so that press release
photos look good.
- Barry wants only the forward facing area to be considered (beam
lumens), discarding the dim spillage as useless light.
- I want megalumens so I can set fire to the riders clothes ahead of
me. I also want megalumens because my principle use is "be seen"
lighting, which means I want to get the attention of motorists.


That's not an accurate collection:

- Frank's main concern is that the light work off a dynamo. All his
other statements are rationalizations of why it is not necessary to
illuminate anything other than the pavement immediately in front of a
rather slow-moving rider. He understands, but does not want to admit,
the importance of proper optics on LED lights in order to illuminate not
only the patch of pavement directly in front of the tire.

- I want both side spill and upward spill. But of course you can do this
without blinding oncoming motorists, which is a red-herring anyway since
on even a two lane road, with the cyclist on the right (or on the left
in countries where they drive on the wrong side of the road), a motorist
coming the other way will not be blinded. The real concern is that on a
narrow MUP that oncoming cyclists not be blinded.

- More beam width is also a side effect of a proper beam shape.

- Barry's emphasis on NASA is unhelpful in marketing bicycle lights. His
lights do have some real advantages in terms of optics and batteries,
and if they were priced at $100 and $200 I think he'd be selling a lot
more of them. It's really hard to work with bicycle shops that demand
Keystone margins, and even harder if you have to go through distribution.

- Your desire to set fire to the clothes of riders in front of you will
not be achieved by LED lights. You could use a flame thrower, but to
achieve sufficient range would require a very heavy and cumbersome
system. You might look into laser modules, i.e.
https://www.amazon.com/dp/B071HB9LX5. Since you'd not need it to run
for long periods of time, you could run it off of a 4S Li-Ion battery pack.

- Jay's main concern is that whatever light he buy be on the bargain
table at one of Portland's famous bicycle shops.


Whatever light there is ends up on a sale table around here somewhere -- or on the internet.

The battery life on my Urban 800 seems to be waning quickly. I don't know why. I like the SECA 1400, but I don't like the separate battery pack. The dyno and LUXOS B are fine for dry nights, although it is poor for urban trail and steeply undulating or ascending MUPs/cemetery roads. I often used my Luxos B with the Urban 800 or a blinky. You would think that with modern technology, you could come up with a highly efficient dyno/light with a shaped beam pattern but not necessarily StVZO and a killer stand light, which probably means using the dyno as a charger. When the bicycle new age arrives, I'm sure that will happen. https://i.pinimg.com/originals/b4/65...0a983373df.jpg

-- Jay Beattie.
  #36  
Old February 25th 18, 11:06 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Inexpensive LUX meter from China to measure your bike lamp'soutput

On 2/25/2018 3:35 PM, jbeattie wrote:

The battery life on my Urban 800 seems to be waning quickly. I don't know why.


Even back in the lead-acid days, I had friends whose battery lights
crapped out unexpectedly.

(Can you imagine having your car headlights operated by a separate
battery you had to manually tend?)

The dyno and LUXOS B are fine for dry nights, although it is poor for urban trail and steeply undulating or ascending MUPs/cemetery roads.


Our MUPs are probably way flatter than yours. You live in hilly terrain.
I can think of only one MUP "dip" where it passes under a bridge and I
have to be slightly more careful.

Regarding cemeteries: There's one a couple blocks from my house, and I
enjoy riding through it at night, trying to spot the owls that hang out
there. My only dyno related problem there occurred when I saw an owl
silhouetted in a tree and tried to use the bike as a big flashlight.
Since that bike has no standlight, I had to spin a wheel to get light.
Not easy!

I often used my Luxos B with the Urban 800 or a blinky. You would think that with modern technology, you could come up with a highly efficient dyno/light with a shaped beam pattern but not necessarily StVZO and a killer stand light, which probably means using the dyno as a charger. When the bicycle new age arrives, I'm sure that will happen. https://i.pinimg.com/originals/b4/65...0a983373df.jpg


Pshaw, you call that a bicycle facility? If it were any good, the two
lanes would be in separate tubes so each could have a pumped tailwind!

Get that done, and _then_ Americans would ride! "Build it and they will
come!"

--
- Frank Krygowski
  #37  
Old February 26th 18, 12:17 AM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 4,018
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Sun, 25 Feb 2018 14:43:04 -0500, Frank Krygowski
wrote:

(* I guess I should use kilo-lumen instead of mega-lumen. The latter
probably won't be available for a year or two.)


1.29 MegaLumens available real soon now:
https://www.youtube.com/watch?v=LStmsIyGldA
Whether it actually delivers 1.29 MegaLumens is questionable.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #38  
Old February 26th 18, 12:58 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Inexpensive LUX meter from China to measure your bike lamp'soutput

On 2/25/2018 6:17 PM, Jeff Liebermann wrote:
On Sun, 25 Feb 2018 14:43:04 -0500, Frank Krygowski
wrote:

(* I guess I should use kilo-lumen instead of mega-lumen. The latter
probably won't be available for a year or two.)


1.29 MegaLumens available real soon now:
https://www.youtube.com/watch?v=LStmsIyGldA
Whether it actually delivers 1.29 MegaLumens is questionable.


It's very bright, but they're claiming 1.29 MegaCd, which is not the
same as 1.29 Mega lumens. (And note that the solid angle of that light's
beam is tiny.) At about 9:00 he claims 1887 lm. That's solidly in the
kilo category.

But it's true that nothing exceeds like excess.

And BTW, the pitchman is just a _little_ over the top! I think he's - um
- in love.

--
- Frank Krygowski
  #39  
Old February 26th 18, 03:37 AM posted to rec.bicycles.tech
Andre Jute[_2_]
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Posts: 10,422
Default 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
  #40  
Old February 26th 18, 05:58 AM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 4,018
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Sun, 25 Feb 2018 18:58:00 -0500, Frank Krygowski
wrote:

On 2/25/2018 6:17 PM, Jeff Liebermann wrote:
On Sun, 25 Feb 2018 14:43:04 -0500, Frank Krygowski
wrote:

(* I guess I should use kilo-lumen instead of mega-lumen. The latter
probably won't be available for a year or two.)


1.29 MegaLumens available real soon now:
https://www.youtube.com/watch?v=LStmsIyGldA
Whether it actually delivers 1.29 MegaLumens is questionable.


It's very bright, but they're claiming 1.29 MegaCd, which is not the
same as 1.29 Mega lumens. (And note that the solid angle of that light's
beam is tiny.) At about 9:00 he claims 1887 lm. That's solidly in the
kilo category.


Oops, false alarm and wishful thinking on my part. Sorry.

But it's true that nothing exceeds like excess.


Bigger numbers always sell better. The problem with megalumen LED's
is that using the best of todays technology, LED's will deliver about
150 lumens/watt. In order to produce 1 Megalumen, the LED's will
requi
1,000,000 lumens / 150 lumens/watt = 6,666 watts
The better 18650 LiIon cells can deliver perhaps 2A without adversely
affecting the battery life (in charge cycles). To deliver 6,666 watts
will requi
6,666 watts / (2A * 3.6V) watts/cell = 926 cells
I suspect that might be a little too large and heavy to be
successfully installed on a bicycle.

The lamp will also be a problem. It will probably use the current 100
watt LED technology, which produces about 6,000 lumens per LED. Notice
the drop to 60 lumens/watt for these monsters. To produce 1 Megalumen
with 100 watt LED's will requi
1,000,000 lumens / 6,000 lumens/watt/LED = 167 LED's
In terms of size, they are about 40 x 40 mm = 0.0016 sq-meters
167 of these would occupy:
167 * 0.0016 = 0.267 sq-meters
If this were a square, it would be about 0.5 meters on a side, which
is probably too large for a bicycle.

Therefore, you can sleep easily and worry free tonite and not have
nightmares of Megalumen lights appearing at your next ride.

And BTW, the pitchman is just a _little_ over the top! I think he's - um
- in love.


Everyone has their own style. At least he's not dull and boring like
many YouTube presentations[1]. Hmmm... I wonder if I should do a
YouTube video demonstrating my method of measuring lumens?


[1] This is a common problem among speakers accustomed to giving live
presentations to an auditorium audience and then switching to YouTube
videos. In order to convey enthusiasm, the speaker uses various body
gestures and facial expressions that are difficult to see in an
auditorium. So, the speaker intentionally exaggerates these gestures
and expressions so they can be seen. However, when doing a YouTube
video, or while being recorded from a TV camera, the camera is a few
feet away and every little gesture and expression can easily be seen
by the audience. If the speaker acts the same in front of the camera
as they might do in front of an auditorium audience, the gestures and
expressions look grotesque and very un-natural. I suspect this might
be the excess enthusiasm that we're seeing in the video.

--
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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