|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
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 |
Ads |
#33
|
|||
|
|||
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
|
|||
|
|||
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
|
|||
|
|||
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
|
|||
|
|||
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
|
|||
|
|||
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
|
|||
|
|||
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
|
|||
|
|||
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
|
|||
|
|||
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 |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Oculus reaches 3000 lumens | Barry Beams | Techniques | 8 | August 22nd 17 04:21 AM |
How to easily measure lumens | Jeff Liebermann | Techniques | 23 | March 26th 17 10:31 PM |
bye, bye postie, another few thousand less bikes! | Mrcheerful[_2_] | UK | 4 | July 29th 10 10:29 PM |
Worth a thousand words ....probably more | DirtRoadie | Racing | 8 | July 28th 09 07:57 PM |
day fifteen thousand and something | Triball | Unicycling | 0 | October 13th 07 04:27 PM |