Best MTB Lighting System?

On Sunday, November 12, 1995 at 12:00:00 AM UTC-8, David Greenblatt wrote:
This query has probably appeared many times before, but I'm a newbie to the group. Any opinions on what the best lighting system for off-road riding is? The days are getting shorter...

Thanks,

David

Look at the Gemini Titan. https://gemini-lights.com/collections/lights/products/titan?variant=17556906503

On Saturday, December 17, 2016 at 2:40:24 PM UTC-8, SMS wrote:
On Sunday, November 12, 1995 at 12:00:00 AM UTC-8, David Greenblatt wrote:
This query has probably appeared many times before, but I'm a newbie to the group. Any opinions on what the best lighting system for off-road riding is? The days are getting shorter...

Thanks,

David

Look at the Gemini Titan. https://gemini-lights.com/collections/lights/products/titan?variant=17556906503

I can't find my lights around here now but sms's look pretty damned expensive to me no matter how effective. These look good if you are riding OFF-ROAD in the dark. But if you are riding on the road you want a couple of rear flashers, a white forward flasher (mine if one of the "Turbo Flashlights) and a strong LED headlight that lights the road well.) These flashers cause cars and trucks to give you a LOT of clearance. But you have to have something to see the path with.

try lights on the bar pointing ahead n 2 too sides.....one on the helmet.

varies sources and colors improve neural response to what is that and depth perception.

On 12/17/2016 5:51 PM, wrote:
On Saturday, December 17, 2016 at 2:40:24 PM UTC-8, SMS wrote:
On Sunday, November 12, 1995 at 12:00:00 AM UTC-8, David Greenblatt wrote:
This query has probably appeared many times before, but I'm a newbie to the group. Any opinions on what the best lighting system for off-road riding is? The days are getting shorter...

Thanks,

David

Look at the Gemini Titan. https://gemini-lights.com/collections/lights/products/titan?variant=17556906503

I can't find my lights around here now but sms's look pretty damned expensive to me no matter how effective. These look good if you are riding OFF-ROAD in the dark. But if you are riding on the road you want a couple of rear flashers, a white forward flasher (mine if one of the "Turbo Flashlights) and a strong LED headlight that lights the road well.) These flashers cause cars and trucks to give you a LOT of clearance. But you have to have something to see the path with.


When OP inquired, the hot setup was a 10W HID with battery
brick about $60. Blinky headlights did not exist yet.

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

On Sat, 17 Dec 2016 14:40:22 -0800 (PST), SMS
wrote:

Look at the Gemini Titan. https://gemini-lights.com/collections/lights/products/titan?variant=17556906503

Mega-lumens!

72,000 lumens (with water cooling):
https://www.youtube.com/watch?v=-vgNh3fLxJc
http://imgur.com/a/dz4y8

90,000 lumens:
http://petapixel.com/2015/11/24/the-worlds-brightest-flashlight-can-light-the-world-with-90000-lumens/

162,000 lumens:
https://www.youtube.com/watch?v=wEFneTFl6_4
https://www.youtube.com/watch?v=we4DU6CZKfU

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Is late...the collection include the Aussie lighthouse ?

The bar rates 4000 lumen.

I have a 14" unit rated 7000L meant for a Jeep bumper, from Amazon.

Yeah 7 is 2X 4 but I have cognitive problems getting linear with the 4000 rating.

How's truth in advertising in the lumens ?

On Sat, 17 Dec 2016 19:04:51 -0800 (PST), DATAKOLL MARINE RESEARCH
wrote:

How's truth in advertising in the lumens ?

Everyone lies, but that's ok because nobody understands optics.

I have a crude way of measuring lumens from anything that produces a
spot beam, such as a headlight or flashlight. It won't work with wide
angle or hemispherical radiators, such as household LED lights bulbs
or linear LED strip fixtures. Here's roughly how updated from one of
my earlier rants on the topic:
https://groups.google.com/forum/?hl=en#!original/rec.bicycles.tech/zy1i8yjNq-0/5q_iIE8YX7YJ
(Quoting with some editing)

In order to accurately measure Lumens, you need an integrating sphere.
https://www.google.com/search?q=integrating+sphere&tbm=isch
The idea is that the sphere reflects all the light produces by the
headlight, in all directions, to the photo detector, producing the
total light output in Lumens. You won't like the price tag of a
laboratory quality integrating sphere. However, you can build your
own. Just be careful about using the correct paint.
http://www.candlepowerforums.com/vb/showthread.php?200334-Building-an-Integrating-Sphere
However, for spot beams, you don't need a integrating sphere.

What you need is a Lux meter:
https://www.google.com/search?q=lux+meter&tbm=isch
http://www.ebay.com/sch/i.html?_nkw=lux+meter
which measures lux and foot-candles. The ones with the hockey puck
on a coil cord are best. $15 and up on eBay. Buy one and measure the
light, calculate the lumens, and then decide how bright you are.

1. Point light at the wall in a dark room at a distance of 1 meter.
There's nothing sacred about the 1 meter distance. If 1 meter seems
too close, just pick another distance.

2. Measure the spot diameter on the wall. If the light slowly fades
away from the hot spot, just guess the half brightness points. If the
spot is oval shaped, measure both the maximum and minimum diameters
and calculate an average.

3. At the same 1 meter distance, use the Lux meter to measure the
brightness. This is not really correct, since lumens is the total
brightness, including the over spray. The brightness will also follow
a Gaussian curve over the spot diameter. Don't worry about these.
There are so many errors in this procedure that another error probably
won't matter.

4. Calculate the beam width in degrees. Dust off the long forgotten
inverse trigonometric functions on your calculator:
Beam_width_in_degrees = 2 * arctan (spot_radius/dist)
whe
spot_radius = 1/2 * spot diameter, in your favorite units of measure
dist = distance between light and spot in same units of measure.

5. Using the values of lux, distance, and beamwidth, plug into the
calculator at the top of:
http://www.ledrise.com/shop_content.php?coID=19
to obtain lumens.

I would be interested in collecting results as I only have a few
bicycle lights and flashlights suitable for testing. Please include
measurements, maker, model, battery type, manufacturers rated lumens,
and condition of battery (new, used, old, leaking, dead).

So far, I have (as corrected):
Light spot_dia dist width bright calc mfg
(cm) (cm) (deg) (lux) (lumens) (lumens)
Planet Bike 1 watt 20 100 11.4 3000 93 76 (new batt)
Maglite 3D LED 13 100 7.4 3600 47 131 (old batt)

I made an expanded list of flashlights and bicycle headlight
measurements, but I can't seem to find it. Maybe later.

If you know the wattage and efficacy (lumens/watt) of the LED's, you
can make a rough guess as to the output in lumens. Most bicycle
lights seem to operate at about 80 lumens/watt. So, a single 1 watt
LED would produce about 80 lumens, minus lens and reflector losses.
That's fairly close to what I measured with my Planet Bike 1 watt LED
light above.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Saturday, December 17, 2016 at 7:45:57 PM UTC-8, Jeff Liebermann wrote:
On Sat, 17 Dec 2016 19:04:51 -0800 (PST), DATAKOLL MARINE RESEARCH
wrote:

How's truth in advertising in the lumens ?

Everyone lies, but that's ok because nobody understands optics.

I have a crude way of measuring lumens from anything that produces a
spot beam, such as a headlight or flashlight. It won't work with wide
angle or hemispherical radiators, such as household LED lights bulbs
or linear LED strip fixtures. Here's roughly how updated from one of
my earlier rants on the topic:
https://groups.google.com/forum/?hl=en#!original/rec.bicycles.tech/zy1i8yjNq-0/5q_iIE8YX7YJ
(Quoting with some editing)

In order to accurately measure Lumens, you need an integrating sphere.
https://www.google.com/search?q=integrating+sphere&tbm=isch
The idea is that the sphere reflects all the light produces by the
headlight, in all directions, to the photo detector, producing the
total light output in Lumens. You won't like the price tag of a
laboratory quality integrating sphere. However, you can build your
own. Just be careful about using the correct paint.
http://www.candlepowerforums.com/vb/showthread.php?200334-Building-an-Integrating-Sphere
However, for spot beams, you don't need a integrating sphere.

What you need is a Lux meter:
https://www.google.com/search?q=lux+meter&tbm=isch
http://www.ebay.com/sch/i.html?_nkw=lux+meter
which measures lux and foot-candles. The ones with the hockey puck
on a coil cord are best. $15 and up on eBay. Buy one and measure the
light, calculate the lumens, and then decide how bright you are.

1. Point light at the wall in a dark room at a distance of 1 meter.
There's nothing sacred about the 1 meter distance. If 1 meter seems
too close, just pick another distance.

2. Measure the spot diameter on the wall. If the light slowly fades
away from the hot spot, just guess the half brightness points. If the
spot is oval shaped, measure both the maximum and minimum diameters
and calculate an average.

3. At the same 1 meter distance, use the Lux meter to measure the
brightness. This is not really correct, since lumens is the total
brightness, including the over spray. The brightness will also follow
a Gaussian curve over the spot diameter. Don't worry about these.
There are so many errors in this procedure that another error probably
won't matter.

4. Calculate the beam width in degrees. Dust off the long forgotten
inverse trigonometric functions on your calculator:
Beam_width_in_degrees = 2 * arctan (spot_radius/dist)
whe
spot_radius = 1/2 * spot diameter, in your favorite units of measure
dist = distance between light and spot in same units of measure.

5. Using the values of lux, distance, and beamwidth, plug into the
calculator at the top of:
http://www.ledrise.com/shop_content.php?coID=19
to obtain lumens.

I would be interested in collecting results as I only have a few
bicycle lights and flashlights suitable for testing. Please include
measurements, maker, model, battery type, manufacturers rated lumens,
and condition of battery (new, used, old, leaking, dead).

So far, I have (as corrected):
Light spot_dia dist width bright calc mfg
(cm) (cm) (deg) (lux) (lumens) (lumens)
Planet Bike 1 watt 20 100 11.4 3000 93 76 (new batt)
Maglite 3D LED 13 100 7.4 3600 47 131 (old batt)

I made an expanded list of flashlights and bicycle headlight
measurements, but I can't seem to find it. Maybe later.

If you know the wattage and efficacy (lumens/watt) of the LED's, you
can make a rough guess as to the output in lumens. Most bicycle
lights seem to operate at about 80 lumens/watt. So, a single 1 watt
LED would produce about 80 lumens, minus lens and reflector losses.
That's fairly close to what I measured with my Planet Bike 1 watt LED
light above.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Do you make any corrections for the bright white of an LED vs the dull yellow of an incandescent?

What ah battery powers SMS recommendation for a 2 hour ride full lumens

On Saturday, December 17, 2016 at 5:40:24 PM UTC-5, SMS wrote:
On Sunday, November 12, 1995 at 12:00:00 AM UTC-8, David Greenblatt wrote:
This query has probably appeared many times before, but I'm a newbie to the group. Any opinions on what the best lighting system for off-road riding is? The days are getting shorter...

Thanks,

David

Look at the Gemini Titan. https://gemini-lights.com/collections/lights/products/titan?variant=17556906503

Not bad. Only took 21 YEARS to get him the answer. LOL Talk about ressurecting old Zombie threads!

Cheers