Best MTB Lighting System?

On 2016-12-18 10:47, Sir Ridesalot wrote:
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


Shazam! That's brighter than my Cree XM-L. If they angle the individual
lights correctly there should be a nice beam spread. I had to do that
with an aftermarket diffusor lens.


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


This is the Internet on which things seemingly live forever. I am still
receiving email requests for a PDF file from a post of mine about how to
change the halogen bulb on a certain designer desk lamp. I wrote it over
10 years ago and meantime the factory web link broke.

--
Regards, Joerg

http://www.analogconsultants.com/

On 2016-12-18 10:14, DATAKOLL MARINE RESEARCH wrote:
What ah battery powers SMS recommendation for a 2 hour ride full lumens


It says so in the link. Eight cell usually means 8*18650 Li-Ion. Also,
not the Ah matter but the Wh because the amp-hours are half when two
sets in series but the watt-hours remain the same. Realistically you
need north of 50Wh for this light to run for 2h. I have 60Wh of usable
capacity when charged to the brim (which I only do for longer rides) and
that affords me around 5h of 1000-lumen light. I ride with DRL but not
always full power.

--
Regards, Joerg

http://www.analogconsultants.com/

On Sun, 18 Dec 2016 09:27:11 -0800 (PST), wrote:

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

No. I accept the spectral response of the lux meter, which tries to
mimic the spectral response of the human eye:
http://www.deterco.com/products/Spectronics/reative_spectral_response.gif
This is in contrast to a photographic light meter, which more closely
resembles the response of a film, CMOS, or CCD imager. The good news
is that the sensor and filter used in a proper integrating sphere used
to measure lumens, is the same as the typical lux meter which are
calibrated under a "standard light tungsten source of 2856K". My
meter is an LX-102:
http://www.lutron.com.tw/ugC_ShowroomItem_Detail.asp?hidKindID=1&hidTypeID= 37&hidCatID=&hidShowID=242&hidPrdType=&txtSrhData=
The manual offers correction factors for different illumination
sources:
Tungsten lamp x1.00
Mercury lamp x0.95
Fluorescent lamp x0.97
Daylight x0.95
Sorry, but no numbers found for LED. Since we would be comparing LED
lights against other LED lights, the absolute light outputs might be
in question, but the relative light outputs will be valid for a
comparison.

However, there's a different problem. White LED's are a combination
of a blue LED light source exciting a mixture of mostly yellow
phosphor. To the eye, it looks white. However, to a camera or
instrument, which usually has a built in UV filter, the light is more
yellow. For example, this is a photo of a 9 watt EcoSmart LED:
http://802.11junk.com/jeffl/crud/EcoSmart%209%20Watt%20LED.jpg
To my eye, the LED looks white. To my camera, it's yellow.

I don't want to go into all the sources of error in my method. Some
of the bigger problems a
1. Reflectivity of the wall used to project the spot.
2. Uneven brightness across the spot.
3. Room illumination interference.
4. Fuzzy border of the spot used to measure its diameter.
5. Elliptical spot caused by bean misalignment or eccentric
reflector.
6. Light rings outside of measurement area caused by lens or
reflector.
7. Different LED color temperatures.



--
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 Sunday, December 18, 2016 at 10:47:43 AM UTC-8, Sir Ridesalot wrote:
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

Yeah, Most of us took almost 2 hours to respond to sms posting.

On Sun, 18 Dec 2016 10:14:31 -0800 (PST), DATAKOLL MARINE RESEARCH
wrote:

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

That's easy to calculate. If you equip your bicycle with my
recommended 100,000 lumen headlight and death ray street sweeper, my
guess(tm) is the luminous efficacy of the device is about 40
lumens/watt, mostly due to the efficiency drop caused by hot LEDs.
That's only about 2-3 times better than a halogen bulb, but we won't
go there today. At full power, such a light would requi
100,000 lumens / 40 lumens/watt = 2,500 watts
for 2 hrs or 5,000 watt-hrs. It's considered bad form to totally
discharge a LiIon battery, so I'll give myself 100% headroom requiring
a 10,000 watt-hr battery.

My guess(tm) is a 100,000 lumen system would probably be built using a
36 volt string (10 LiIon 3.6v cells in series) with additional strings
to increase the current capacity.
5,000 watt-hrs / 36v = 139 A-hrs
You can buy big LiIon batteries as automobile battery replacements.
http://www.lithiumion-batteries.com
Here's a 12v 150 A-hr battery for only $1,900. You'll need 3 of them
to get 36v. Incidentally, they weigh 65lbs each.

--
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 Sunday, December 18, 2016 at 11:42:24 AM UTC-8, Jeff Liebermann wrote:
On Sun, 18 Dec 2016 09:27:11 -0800 (PST), wrote:

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

No. I accept the spectral response of the lux meter, which tries to
mimic the spectral response of the human eye:
http://www.deterco.com/products/Spectronics/reative_spectral_response.gif
This is in contrast to a photographic light meter, which more closely
resembles the response of a film, CMOS, or CCD imager. The good news
is that the sensor and filter used in a proper integrating sphere used
to measure lumens, is the same as the typical lux meter which are
calibrated under a "standard light tungsten source of 2856K". My
meter is an LX-102:
http://www.lutron.com.tw/ugC_ShowroomItem_Detail.asp?hidKindID=1&hidTypeID= 37&hidCatID=&hidShowID=242&hidPrdType=&txtSrhData=
The manual offers correction factors for different illumination
sources:
Tungsten lamp x1.00
Mercury lamp x0.95
Fluorescent lamp x0.97
Daylight x0.95
Sorry, but no numbers found for LED. Since we would be comparing LED
lights against other LED lights, the absolute light outputs might be
in question, but the relative light outputs will be valid for a
comparison.

However, there's a different problem. White LED's are a combination
of a blue LED light source exciting a mixture of mostly yellow
phosphor. To the eye, it looks white. However, to a camera or
instrument, which usually has a built in UV filter, the light is more
yellow. For example, this is a photo of a 9 watt EcoSmart LED:
http://802.11junk.com/jeffl/crud/EcoSmart%209%20Watt%20LED.jpg
To my eye, the LED looks white. To my camera, it's yellow.

I don't want to go into all the sources of error in my method. Some
of the bigger problems a
1. Reflectivity of the wall used to project the spot.
2. Uneven brightness across the spot.
3. Room illumination interference.
4. Fuzzy border of the spot used to measure its diameter.
5. Elliptical spot caused by bean misalignment or eccentric
reflector.
6. Light rings outside of measurement area caused by lens or
reflector.
7. Different LED color temperatures.



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

I just can't put my hands on it but I had a large battery headlight/taillight combo, but they had incandescent lights. When I added an LED it really knocked me out how much more the road was lit. And they supposedly had the same candlepower.

On Sun, 18 Dec 2016 12:17:38 -0800 (PST), wrote:

I just can't put my hands on it but I had a large battery
headlight/taillight combo, but they had incandescent lights.
When I added an LED it really knocked me out how much more
the road was lit. And they supposedly had the same candlepower.

Watch your terms here. Candlepower is (or was) a measure of luminous
intensity, also known as brightness, at a given point. There is no
consideration for the area illuminated, as is the case with lumens.
Given good optics, I could concentrate the output from a single LED,
and produce candlepower higher than that produced by the noon sun.

If both lights claimed the same number of lumens, then I would be
worried.

Oh crap. Lunch is on fire...

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

Http://goo.gl/7Xg9pP

2-3x vs halogen... $$$ but maxs the system with 8-100w n 2 65w halogens...cuts down on ch66.

Cost for light units goes up same plus.

Lumens in bike lights...assume catete more honest ? Is somewhat akin to sleeping bag ratings.

For the casual observer

On 12/17/2016 5:04 PM, AMuzi wrote:

snip

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

It looks like no one responded to his post until now. He may have been
waiting.


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On Sun, 18 Dec 2016 14:42:52 -0800 (PST), DATAKOLL MARINE RESEARCH
wrote:


2-3x vs halogen...

Plagiarized from:
http://www.fcgov.com/utilities/img/site_specific/uploads/led-efficiency.pdf

Light Source Typical Luminous Efficacy Range in lm/W
(varies depending on wattage and lamp type)
Incandescent (no ballast) 10-18
Halogen (no ballast) 15-20
Compact fluorescent (CFL) (incl. ballast) 35-60
Linear fluorescent (incl. ballast) 50-100
Metal halide (incl. ballast) 50-90
Cool white LED 4000K (incl. driver) 60-92
Warm white LED 4000K (incl. driver) 27-54

This is from 2009. LED efficacy has improved somewhat in the last few
year.

$$$ but maxs the system with 8-100w n 2 65w halogens...cuts down on ch66.

Could you translate that into English?

Cost for light units goes up same plus.

No, it does not. Incandescent generates far more heat, which must be
somehow conducted or radiated away. In large lighting systems, that
means fans or water cooling. An LED lighting system will generate
many times the light of an incandescent system using an identical
cooling system.

Lumens in bike lights...assume catete more honest ?

Everyone lies. It's widespread because bigger numbers sell better.

The problem is that LED output and efficacy are measured at 25C. Even
my cheap Chinese flashlight doesn't run at 25C. A headlight under
test would need to be air or water cooled to 25C to make that
measurement. To avoid that hassle, LED's are measured using very
narrow pulses which does not give the LED time to get hot. Neither of
these test conditions resemble anything you'll see on a bicycle or in
a flashlight.


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