Light & Motion 3-watt LED headlight

Peter Cole wrote:
:: Joe Faust wrote:
::: On Wed, 12 Oct 2005 22:18:12 -0400, "Rich Clark"
::: wrote:
:::
:::
:::: "David L. Johnson" wrote in message
:::: news ::::
::::: Has LED lighting come of age yet? Are these 3-watt LED lights
::::: adequate to light the road --- to see as well as to be seen?
::::: Anyone use these yet? My Nightrider battery is dying and
::::: irreplaceable, and I am looking for something as usable.
::::
:::: I ordered one that I expect to be delivered tomorrow or Friday.
:::: The test I read indicated that it might well be sufficient for
:::: standalone road use, and it certainly looks convenient to use.
:::: Reviews are good; see:
::::
::::
http://www.cyclingnews.com/tech.php?...nd_motion_vega
::::
:::: and
::::
::::
http://www.bikefriday.com/main.cfm?f...ategory=S hop
::::
:::: I'll follow up next week after I've had a chance to use it.
::::
:::: RichC
:::
:::
:::
http://www.cateye.com/en/products/vi...d=7&subCatId=2
::: Cateye has a less expensive alternate to the Light & Motion Vega
::: LED Headlight. The cateye HL-EL510 costs about $60 or £40, and
::: ouptuts 800 candlepower or approximately 62 lumens, vs Vega's $175
::: and 95 lumen on high.
:::
::: On High the Vega runs 2 hours on internal Nicad, vs the Cateye 30
::: hours on 4 AA.
:::
::
:: Something sounds a little fishy. If a 2.5W (halogen) light runs for
:: 3 hr on 4 AA's, how can a 1W light run 30 hr on the same batteries?
::
:: I have had a Nitehawk Emitter for about 6 months, which is a 1W LED
:: lamp. Its rated for 8 hr with 4 AA batteries.

May I ask why you got ride of it? I bought one last winter that I never
really have used because I don't like having dark to the sides and also due
to the fact that I can't see my bike on a really dark night. so I'm thinking
of getting a helmet light too, and maybe adding a second light on the
handlebar, just to get a wider beam. I have been testing my Nitehawk
Emitter since the night before last....so far it's still going on high beam
for over 24 hours....sounds fishy to me, perhaps this unit is defective and
my high beam is not what it should be. I have no means for comparison,
since I don't have another Emitter.

I find it to be
:: comparable to a 2.5W halogen like the Cateye MicroII (I have 3 of
:: those). I paid about $30 for the Nitehawk, the Cateyes are as low as
:: $8 recently. The current generation of white LEDs are somewhat more
:: efficient than halogen, perhaps 2x, but not 10x.

Rich Clark wrote:

::
::
http://www.bikefriday.com/main.cfm?f...ategory=S hop

I don't know if I can trust my impressions over this video, BUT, my
impression is that my Nite-hawk Emitter has a slightly wider beam and lasts
longer (currently over 24 hours on high beam!). And the bright white light
is nice....

I'd love to hear comments on this....

Roger Zoul wrote:
Peter Cole wrote:
:: Joe Faust wrote:
::: On High the Vega runs 2 hours on internal Nicad, vs the Cateye 30
::: hours on 4 AA.
:::
::
:: Something sounds a little fishy. If a 2.5W (halogen) light runs for
:: 3 hr on 4 AA's, how can a 1W light run 30 hr on the same batteries?
::
:: I have had a Nitehawk Emitter for about 6 months, which is a 1W LED
:: lamp. Its rated for 8 hr with 4 AA batteries.

May I ask why you got ride of it? I bought one last winter that I never
really have used because I don't like having dark to the sides and also due
to the fact that I can't see my bike on a really dark night.

I still have it, I bought it for my son, who crashed and broke the mount
(oddly, the light was not on the bike), I've been debating whether to go
through Nitehawk's reportedly crappy customer service to get a new one.
I've been using it as a work light, unfortunately I found that exposure
to automobile brake fluid (don't ask) caused the lens to crack. It still
works fine though. As a matter of fact, last week it allowed us to pick
our way through a narrow 3/4 mile harbor channel when we got caught out
after sunset on our sailboat in a very dense fog.


I have been testing my Nitehawk
Emitter since the night before last....so far it's still going on high beam
for over 24 hours....sounds fishy to me, perhaps this unit is defective and
my high beam is not what it should be. I have no means for comparison,
since I don't have another Emitter.

I'm still on my original batteries, I'm guessing my total time used so
far is several hours, although I haven't been keeping track. I'd be
surprised if the light's burn time was really that much longer than
Nitehawk's own spec of 8 hr -- which relates roughly to a 1W electrical
load. My concern with the lights that claim 1W and 30 hr is that they're
using some kind of "incandescent equivalent" rating, like some of the
florescent bulb makers do.

During your lifetime test are you sure you're on the "high" setting?

When I first got the light I did a comparison with the Cateye MicroII
and felt that the Emitter was perhaps slightly dimmer and narrower, but
had a more even and much whiter beam. I judged them to be about equal in
usability, with the big Emitter advantage primarily being much longer
battery and bulb life, the low beam and whiteness over battery life
being a bonus. I like it well enough that I'll probably get another when
I can find it for $30-35USD.

On Thu, 13 Oct 2005 12:48:32 +0000, Eric Babula wrote:

I'll admit I'm a little ignorant with regards to lighting. I have a
VistaLite Nightstick 15 (two lamps: a 5W and 10W). I mostly use the 5W
to shine at oncoming cars, and the 10W down on the road in front of me.
Even with the 10W lamp, I sometimes feel that I'd like even more light
than I have.

Now, this Light & Motion is only a 3W light. Is that really enough for
nighttime commuting on the road?

Don't you have any compact florescent lightbulbs? "60 watts of light for
only 14 watts of power"? Different lights use power differently.
Florescent bulbs are more efficient than incandescent bulbs, since less of
the energy is wasted as heat.

It's the same idea with various bike lights. Current halogen bulbs are
more efficient than standard incandescent, and HID is even better. But
LED lights are better still, in terms of light per watt. The limitation
with LEDs has been getting one big enough with enough output to use as a
headlight, and with a decent color. Taillights are almost universally
LEDs now, since they give off great be-seen light and even tiny batteries
last nearly forever. That was not the case for incandescent rear lights.

Or, are there other standards I need to
know about, so that this lamp gives off as much or more light than my
VistaLite?

This is more or less the question I asked. It seems at least close.


--

David L. Johnson

__o | What is objectionable, and what is dangerous about extremists is
_`\(,_ | not that they are extreme, but that they are intolerant.
(_)/ (_) | --Robert F. Kennedy

David L. Johnson wrote:
On Thu, 13 Oct 2005 12:48:32 +0000, Eric Babula wrote:

Or, are there other standards I need to
know about, so that this lamp gives off as much or more light than my
VistaLite?

This is more or less the question I asked. It seems at least close.

I have a 15W single-lamp Niterider halogen, which has been a reliable
and sufficiencly bright light. But the battery uses up a bottle cage,
and now alsoneeds to be replaced.

I have a dual-halogen Performance light, with 15W total (one flood, one
spot), that has also been reliable but is not as subjectively bright as
the Niterider, and the very heavy battery also takes up a bottle cage.

And I have an Emitter, the Performance-branded one. It is not
sufficient by itself, but I value it as a supplement/backup in case of
lamp or battery failure of my main light.

I'm trying the L&M Vega in hope that it can equal the Niterider in
terms of overall brightness on the pavement, and allow me to reclaim
that bottle cage. Not having that second cage available makes me have
to carry my coffee thermos elsewhere, which forces me to add a pannier,
and the whole thing ends up adding an inordinate amount of weight to
the bike just to accommodate the battery. So it will be worth it to me
if I can use this new self-contained light instead, perhaps in tandem
with the Emitter.

RichC

David L. Johnson wrote:

Don't you have any compact florescent lightbulbs? "60 watts of light for
only 14 watts of power"? Different lights use power differently.
Florescent bulbs are more efficient than incandescent bulbs, since less of
the energy is wasted as heat.

It's the same idea with various bike lights. Current halogen bulbs are
more efficient than standard incandescent, and HID is even better. But
LED lights are better still, in terms of light per watt.

I don't believe that's the case.

I know LEDs are improving very rapidly. But people have been claiming
for years that white LEDs are more efficient (more lumens per watt)
than halogen bulbs. It's my understanding that it only _recently_
became true for some white LEDs, but not most of them.

AFAIK, nobody is claiming that LEDs are more efficient than HID lamps.

Admittedly I'm just going by memory, and I've found data rather hard to
come by. But see
http://www2.whidbey.net/opto/LEDFAQ/...0Pages.html#Q7
as one reference on this point.

Again, LEDs are improving rapidly. And that page is a few years old, I
think. But it's a little early to imagine LEDs beat all comers.

BTW, I think red LEDs beat red incandescents long ago, partly because
the incandescent actually puts out white (i.e. a mix of wavelengths)
and the red lens absorbed most of that white, leaving only the red to
pass. That caused much less efficiency than a white incandescent.

- Frank Krygowski

Peter Cole wrote:

I have had a Nitehawk Emitter for about 6 months, which is a 1W LED
lamp. Its rated for 8 hr with 4 AA batteries. I find it to be comparable
to a 2.5W halogen like the Cateye MicroII (I have 3 of those). I paid
about $30 for the Nitehawk, the Cateyes are as low as $8 recently. The
current generation of white LEDs are somewhat more efficient than
halogen, perhaps 2x, but not 10x.

Unfortunately, much of the efficiency gain is lost because it is not
possible to focus the output of the LED very well.

When you move to the 5W LEDs, they have a very short lifetime, and are
expensive to replace, but the 3W LEDs have a reasonable lifespan.

For "being seen" the LED lights are excellent, but for lighting up the
road they are not great.

REI has a good deal on the CygoLite Night Rover NiMH XTRA, for $70. It's
one 6W and one 10W beam.
"http://www.rei.com/product/47842645.htm?vcat=REI_SSHP_CYCLING_TOC"

Eric Babula wrote:

Now, this Light & Motion is only a 3W light. Is that really enough for
nighttime commuting on the road? Or, are there other standards I need to
know about, so that this lamp gives off as much or more light than my
VistaLite?

I believe candlepower ratings are what you'd want to compare.

Three Watts can be plenty sufficient for night time *road*
commuting. I use a 3W Lumotec Plus light powered by a
generator on my primary commuter.

How the lense shapes the light is really more important I
think than a Wattage rating.


SMH

SMS wrote:
Peter Cole wrote:

I have had a Nitehawk Emitter for about 6 months, which is a 1W LED
lamp. Its rated for 8 hr with 4 AA batteries. I find it to be
comparable to a 2.5W halogen like the Cateye MicroII (I have 3 of
those). I paid about $30 for the Nitehawk, the Cateyes are as low as
$8 recently. The current generation of white LEDs are somewhat more
efficient than halogen, perhaps 2x, but not 10x.


Unfortunately, much of the efficiency gain is lost because it is not
possible to focus the output of the LED very well.

Given that the actual emitting surface of the LED is small, I'd think it
would be easier to focus them. The uniformity of the narrow Nitehawk
lamp seems to bear that out, if anything, the beam might be too narrow,
suggesting that it collimates well with a relatively small reflector. I
find them impressive side-by-side with a 2.5W halogen, but not
stunningly so -- by that I mean comparable light at a bit more than 1/3
the power consumption and a nicer beam pattern. Like those halogens, I
think it qualifies as a "bare minimum" bike light.

http://members.misty.com/don/led.html#w

UPDATE 7/31/2005: Lumileds white Luxeons typically produce 45 lumens at
350 mA with a typical voltage drop at 3.42 mA. This works out to 37.6
lumens/watt, although at a chip temperature of 25 degrees C which
requires a heatsink temperature of typically 1 degree C.

On Thu, 13 Oct 2005 10:17:58 -0700, frkrygow wrote:


I know LEDs are improving very rapidly. But people have been claiming
for years that white LEDs are more efficient (more lumens per watt)
than halogen bulbs. It's my understanding that it only _recently_
became true for some white LEDs, but not most of them.

AFAIK, nobody is claiming that LEDs are more efficient than HID lamps.

Admittedly I'm just going by memory, and I've found data rather hard to
come by. But see
http://www2.whidbey.net/opto/LEDFAQ/...0Pages.html#Q7
as one reference on this point.

Well, I think their data is either old, or wrong, or someone else is. But
one thing is really confusing. As a bulb consumes power, that energy has
but two places to go, either light or heat. That article did claim that
LEDs run much cooler, but consume more energy than an incandescent ---
that seems to be contradictory on its face unless a lot of ultraviolet
light is thrown off as well. L&M claim their 3-watt LED produces 85 lumens
(it is also overdriven at 3.8-watts of power according to someone earlier
on this thread), for 22.3 lumens/watt, but that is much more than the less
than 8 lumens/watt claimed in the link above (they state that
incandescents produce 8 lumens/watt and are more efficient than LEDs).


--

David L. Johnson

__o | Enron's slogan: Respect, Communication, Integrity, and
_`\(,_ | Excellence.
(_)/ (_) |