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SIX thousand and FIVE hundred lumens !!!!!!!!!!



 
 
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  #31  
Old October 4th 18, 01:33 PM posted to rec.bicycles.tech
Emanuel Berg[_2_]
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Posts: 1,035
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

FL 1 Standard (?)
18h
38lm
40m (range)
400cd (?)


OK, so FL 1 is the "ANSI FL1 Standard" ("FL" is
"flashlight", I take it) and cd is "candela".
I suppose one has to read the article [1] to
learn what sense to make of the
400cd specification.

[1] http://www.led-resource.com/ansi-fl1-standard/

--
underground experts united
http://user.it.uu.se/~embe8573
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  #32  
Old October 4th 18, 04:02 PM posted to rec.bicycles.tech
Joerg[_2_]
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Posts: 6,016
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 2018-10-01 15:14, wrote:
http://reviews.mtbr.com/magicshine-l...2018-interbike

The beloved Magicshine brings us what we finally need in bike lights.
Thanks to all the gods. 6500 lumens! I think you can have either
5000 or 1500 or all 6500 lumens. Thankfully now we will not only be
able to blind everyone else on the road or trail, but we can now
cause their eyeballs to burst into flames and maybe hopefully their
heads will also explode. Yeah!!!!!!


This one for their rear light is weird, quote "A sleep mode is triggered
after one minute of inaction to save power, any vibration will
immediately re-activate the unit".

So the light will go out while waiting at an intersection? Really?
Nobody raised their hand during the design review? Was there even a
design review?

[...]

--
Regards, Joerg

http://www.analogconsultants.com/
  #33  
Old October 4th 18, 04:10 PM posted to rec.bicycles.tech
Duane[_2_]
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Posts: 401
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 04/10/2018 11:02 AM, Joerg wrote:
On 2018-10-01 15:14, wrote:
http://reviews.mtbr.com/magicshine-l...2018-interbike

The beloved Magicshine brings us what we finally need in bike lights.
Thanks to all the gods.Â* 6500 lumens!Â* I think you can have either
5000 or 1500 or all 6500 lumens.Â* Thankfully now we will not only be
able to blind everyone else on the road or trail, but we can now
cause their eyeballs to burst into flames and maybe hopefully their
heads will also explode.Â* Yeah!!!!!!


This one for their rear light is weird, quote "A sleep mode is triggered
after one minute of inaction to save power, any vibration will
immediately re-activate the unit".

So the light will go out while waiting at an intersection? Really?
Nobody raised their hand during the design review? Was there even a
design review?

[...]


Maybe anyone with 6500 lumens isn't stopping at red lights. Or maybe
they just jiggle the bike to turn it on again...
  #34  
Old October 4th 18, 05:42 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 4,018
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On Thu, 04 Oct 2018 14:33:34 +0200, Emanuel Berg
wrote:

FL 1 Standard (?)
18h
38lm
40m (range)
400cd (?)


OK, so FL 1 is the "ANSI FL1 Standard" ("FL" is
"flashlight", I take it) and cd is "candela".
I suppose one has to read the article [1] to
learn what sense to make of the
400cd specification.

[1] http://www.led-resource.com/ansi-fl1-standard/


Maybe reading the definitions of candelas, lux, and lumens might help:
https://blog.1000bulbs.com/home/whats-the-difference-between-candela-lux-and-lumens
https://www.knivesandtools.com/en/ct/torches-lux-candela-lumen.htm
There are calculators for converting between these. Be sure to read
about "solid angles".

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #35  
Old October 4th 18, 06:14 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 2018-10-04 08:10, Duane wrote:
On 04/10/2018 11:02 AM, Joerg wrote:
On 2018-10-01 15:14, wrote:
http://reviews.mtbr.com/magicshine-l...2018-interbike

The beloved Magicshine brings us what we finally need in bike lights.
Thanks to all the gods. 6500 lumens! I think you can have either
5000 or 1500 or all 6500 lumens. Thankfully now we will not only be
able to blind everyone else on the road or trail, but we can now
cause their eyeballs to burst into flames and maybe hopefully their
heads will also explode. Yeah!!!!!!


This one for their rear light is weird, quote "A sleep mode is
triggered after one minute of inaction to save power, any vibration
will immediately re-activate the unit".

So the light will go out while waiting at an intersection? Really?
Nobody raised their hand during the design review? Was there even a
design review?

[...]


Maybe anyone with 6500 lumens isn't stopping at red lights.



I've had a rider in front of me in downtown Sacramento who blew through
every single red light. Couldn't believe it. He was slower so I always
caught up, then he pulled away from me at the next red light. His bike
was completely unlit as unfortunately most American road bikes are.


... Or maybe they just jiggle the bike to turn it on again...



"Attention, this light only works properly when mounted on a vibrator" :-)

--
Regards, Joerg

http://www.analogconsultants.com/
  #36  
Old October 4th 18, 06:26 PM posted to rec.bicycles.tech
Emanuel Berg[_2_]
external usenet poster
 
Posts: 1,035
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

Jeff Liebermann wrote:

OK, so FL 1 is the "ANSI FL1 Standard" ("FL"
is "flashlight", I take it) and cd is
"candela". I suppose one has to read the
article [1] to learn what sense to make of
the 400cd specification.

[1] http://www.led-resource.com/ansi-fl1-standard/


Maybe reading the definitions of candelas,
lux, and lumens might help


I don't think so

https://blog.1000bulbs.com/home/whats-the-difference-between-candela-lux-and-lumens
https://www.knivesandtools.com/en/ct/torches-lux-candela-lumen.htm
There are calculators for converting between
these. Be sure to read about "solid angles".


OK, I read the two web pages! (There is nothing
on solid angles what I could see.)

What *I think* I understood is that

LUX: lux is describing how bright the object
will be, or how big an area (floor or wall) you
can enlight, by pointing the flashlight at it.

LUMEN: lumen is how much light that comes from
the light source, only this doesn't take into
account if and how the light is obstructed or
enforced/directed, e.g. because of the
construction of the lamp, what lens there
is and where, etc.

CANDELA: candela takes into account
obstructions (various blockings of the light)
but also the enforcing of it thru a lens.
This means that candela is a good unit to
determine how far away the light will actually
be visible, for example if you waive it to the
sea from the beach of a deserted island...

For bike applications, it seems for commuting
in a well-lit city with traffic, you'd want
candela, for MTB you'd want lux, and for
touring, you'd want a combination

--
underground experts united
http://user.it.uu.se/~embe8573
  #37  
Old October 4th 18, 06:40 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 10/4/2018 11:02 AM, Joerg wrote:
On 2018-10-01 15:14, wrote:
http://reviews.mtbr.com/magicshine-l...2018-interbike

The beloved Magicshine brings us what we finally need in bike lights.
Thanks to all the gods.Â* 6500 lumens!Â* I think you can have either
5000 or 1500 or all 6500 lumens.Â* Thankfully now we will not only be
able to blind everyone else on the road or trail, but we can now
cause their eyeballs to burst into flames and maybe hopefully their
heads will also explode.Â* Yeah!!!!!!


This one for their rear light is weird, quote "A sleep mode is triggered
after one minute of inaction to save power, any vibration will
immediately re-activate the unit".

So the light will go out while waiting at an intersection? Really?
Nobody raised their hand during the design review? Was there even a
design review?


First, their definition of "sleep mode" may not be "goes out." It could,
I suppose, just become much dimmer. In any case, it would be easy enough
to jiggle the bike a bit to turn it back on.

But it's probably not necessary. Ohio law specifically permits lights
that go out when the bike is stationary, and there's never been a report
of a death or serious injury caused by that feature. When cyclists stop,
it's almost always because of a red light or stop sign. Motorists stop
for those things as well (in fact, more often than cyclists do). A
motorist coming to a stop at night will see a stationary cyclist in the
lane in front of him.

--
- Frank Krygowski
  #38  
Old October 4th 18, 07:04 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 10/4/2018 1:26 PM, Emanuel Berg wrote:

For bike applications, it seems for commuting
in a well-lit city with traffic, you'd want
candela, for MTB you'd want lux, and for
touring, you'd want a combination


I'd say that for on-road bike applications, what you should want is good
optical design. Here's why:

With proper optics, it takes very few lumens to light the road surface
well enough for safety. And that should be your top priority. There's
plenty of hype about motorists running over cyclists. We even have one
poster who has claimed there's great hazard from tree branches just six
feet above above a road surface. But in real life, the great majority of
bike crashes are caused by problems with the road surface - slippery
spots, potholes, streetcar tracks and the like.

So you want to see the road surface well. The unit of measurement that
applies is lux - but simply giving one lux number doesn't differentiate
good lights from bad. Putting plenty of lux in one spot (say) two meters
in front of a cyclist is worse than useless. A "hot spot" harms a
person's night vision and makes it harder to see outside that spot.

What you want is an even spread of perceived illumination on the road,
plus (for faster riding) good "throw" down the road just below the
horizon. This requires a complex beam shape, one that actually throws
fewer lumens down close to the cyclist, gradually increasing further in
front of the cyclist, then an even brighter beam just below the horizon.
And, of course, you want adequate spread side to side.

If you have a headlight that illuminates the roadway sufficiently, you
_will_ be adequately visible to oncoming traffic. IOW, they have enough
candelas. Even weak novelty lights are adequately visible to oncoming
traffic, and those don't light the road surface at all.

--
- Frank Krygowski
  #39  
Old October 4th 18, 07:12 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 2018-10-04 10:40, Frank Krygowski wrote:
On 10/4/2018 11:02 AM, Joerg wrote:
On 2018-10-01 15:14, wrote:
http://reviews.mtbr.com/magicshine-l...2018-interbike

The beloved Magicshine brings us what we finally need in bike lights.
Thanks to all the gods. 6500 lumens! I think you can have either
5000 or 1500 or all 6500 lumens. Thankfully now we will not only be
able to blind everyone else on the road or trail, but we can now
cause their eyeballs to burst into flames and maybe hopefully their
heads will also explode. Yeah!!!!!!


This one for their rear light is weird, quote "A sleep mode is
triggered after one minute of inaction to save power, any vibration
will immediately re-activate the unit".

So the light will go out while waiting at an intersection? Really?
Nobody raised their hand during the design review? Was there even a
design review?


First, their definition of "sleep mode" may not be "goes out." It could,
I suppose, just become much dimmer. In any case, it would be easy enough
to jiggle the bike a bit to turn it back on.


Not very smart on the part of the design engineers.


But it's probably not necessary. Ohio law specifically permits lights
that go out when the bike is stationary, ...



Not a smart decision by the lawmakers.


... and there's never been a report
of a death or serious injury caused by that feature.



Grandpa drove without a seat belt all his life and never go hurt, so ...

BTW, it even happens from the front, even by police officers:

https://fox2now.com/2018/07/30/polic...hone-in-video/

Nothing can replace bright light other than even brighter lights. Which
both of my bikes have.


... When cyclists stop,
it's almost always because of a red light or stop sign. Motorists stop
for those things as well (in fact, more often than cyclists do). A
motorist coming to a stop at night will see a stationary cyclist in the
lane in front of him.


Not if you are waiting in a turn lane without a light. That's where a
local cyclist was hit, hard. I don't remember if she survived but she
was mangled pretty badly.

--
Regards, Joerg

http://www.analogconsultants.com/
  #40  
Old October 4th 18, 07:28 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default SIX thousand and FIVE hundred lumens !!!!!!!!!!

On 10/4/2018 1:04 PM, Frank Krygowski wrote:
On 10/4/2018 1:26 PM, Emanuel Berg wrote:

For bike applications, it seems for commuting
in a well-lit city with traffic, you'd want
candela, for MTB you'd want lux, and for
touring, you'd want a combination


I'd say that for on-road bike applications, what you should
want is good optical design. Here's why:

With proper optics, it takes very few lumens to light the
road surface well enough for safety. And that should be your
top priority. There's plenty of hype about motorists running
over cyclists. We even have one poster who has claimed
there's great hazard from tree branches just six feet above
above a road surface. But in real life, the great majority
of bike crashes are caused by problems with the road surface
- slippery spots, potholes, streetcar tracks and the like.

So you want to see the road surface well. The unit of
measurement that applies is lux - but simply giving one lux
number doesn't differentiate good lights from bad. Putting
plenty of lux in one spot (say) two meters in front of a
cyclist is worse than useless. A "hot spot" harms a person's
night vision and makes it harder to see outside that spot.

What you want is an even spread of perceived illumination on
the road, plus (for faster riding) good "throw" down the
road just below the horizon. This requires a complex beam
shape, one that actually throws fewer lumens down close to
the cyclist, gradually increasing further in front of the
cyclist, then an even brighter beam just below the horizon.
And, of course, you want adequate spread side to side.

If you have a headlight that illuminates the roadway
sufficiently, you _will_ be adequately visible to oncoming
traffic. IOW, they have enough candelas. Even weak novelty
lights are adequately visible to oncoming traffic, and those
don't light the road surface at all.


+1, covers all the important points well.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


 




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