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Old 05-29-2013, 09:06 AM   #8686
SteveAZ
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I should also be more clear about "quality of light". What we want is to be able to see the road and potential obstacles optimally. Many optical qualities effect this..

Brightness - far from everything but if all other factors are equal, more gives better ability to pick out objects and further reach.

Focus (lens/reflector) - this will always be a compromise between what you see at the periphery verses what's in front of you. Cheap lens/reflector combinations waste light in general inefficiency and lighting up directions we don't care about.

Position - in general the further they are way from your eyes angularly (the enclosed angle from light to object to eyes) the better for contrast etc. Lower mounting is usually best, particularly if there is rain or fog. However on DP motos this can be a big compromise on optimal position for not getting impacted.

Color (spectrum) - way more important than most people realize. Our eyes are tweaked for lime green at night in terms of sensitivity and blue is very bad for night contrast, sharpness and object acquisition and red good. This is all about our retinas, the concentration of the various cells in the retina, their spectral sensitivity and the visual preprocessing that occurs there. Did you realize that most motion detection and object definition (different than identification) occurs there and not in the brain? This preprocessing is why we see after-images and our periphery fades away to nothing if we stare in one direction with static imagery long enough. LED's to date have crap spectrum with a great big spike at blue and then usually one big lump around orange. Some newer ones that are focusing on quality of light of have two lumps but still have the big blue spike. The very nature of the "white" LED makes this a big challenge and I think it will be a while before LED's come even close to a flat spectrum. You would sure want a torque curve that looked more like an incandescent/HID spectrum over an LED. I have to admit that may be a weak metaphor, but hey!
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Old 05-29-2013, 09:45 AM   #8687
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Originally Posted by AZ TOM View Post
Did a little 120 mile ride yesterday, great weather. Trying to find the way through between Camp Wood/ fr21 & 97 that comes out of Kirkland. Fun terrain but ended up back where I started after a few hours. Will try it again soon.





Thought you were heading West for a li'l trip !
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Old 05-29-2013, 09:52 AM   #8688
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I should also be more clear about "quality of light"....
You obviously know lots more on the technical side than I do. All I know is what my eyes tell me but I have one question. You say HID's are the best but then say that the spike in blue on the LED's are bad. Don't the HID's have the same issue? I've never liked HID lights because of the blue that they throw off.
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Old 05-29-2013, 09:56 AM   #8689
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Cyberdos,those are the same cheapies I have but the little Yamaha has a 350 watt stator so no problem with draw. Too old & feeble to do much night riding anyway
They weren't bad but the VFR has finicky electrical issues so I rather have the lights that draws less even though the stator can more than handle them. I've got a voltage meter on the bike and with the bike idling and the cheapies on voltage would drop under 12. With the LED's they never do.
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Old 05-29-2013, 10:14 AM   #8690
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Thought you were heading West for a li'l trip !
After spending the whole morning exploring/lost, I headed home instead of making the trip.
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Old 05-29-2013, 10:19 AM   #8691
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Originally Posted by SteveAZ View Post
I should also be more clear about "quality of light". What we want is to be able to see the road and potential obstacles optimally. Many optical qualities effect this..

Brightness - far from everything but if all other factors are equal, more gives better ability to pick out objects and further reach.

Focus (lens/reflector) - this will always be a compromise between what you see at the periphery verses what's in front of you. Cheap lens/reflector combinations waste light in general inefficiency and lighting up directions we don't care about.

Position - in general the further they are way from your eyes angularly (the enclosed angle from light to object to eyes) the better for contrast etc. Lower mounting is usually best, particularly if there is rain or fog. However on DP motos this can be a big compromise on optimal position for not getting impacted.

Color (spectrum) - way more important than most people realize. Our eyes are tweaked for lime green at night in terms of sensitivity and blue is very bad for night contrast, sharpness and object acquisition and red good. This is all about our retinas, the concentration of the various cells in the retina, their spectral sensitivity and the visual preprocessing that occurs there. Did you realize that most motion detection and object definition (different than identification) occurs there and not in the brain? This preprocessing is why we see after-images and our periphery fades away to nothing if we stare in one direction with static imagery long enough. LED's to date have crap spectrum with a great big spike at blue and then usually one big lump around orange. Some newer ones that are focusing on quality of light of have two lumps but still have the big blue spike. The very nature of the "white" LED makes this a big challenge and I think it will be a while before LED's come even close to a flat spectrum. You would sure want a torque curve that looked more like an incandescent/HID spectrum over an LED. I have to admit that may be a weak metaphor, but hey!
You are using terms here that most people have never heard of... or care too. However I have. To simplify;


L.E.D. (unless filtered) over-expose and therefore flatten objects. Not what you want in an off-road situation.
It is a known fact that a mix of lighting will make a much more user friendly halo of light. Example... how many cans do you see on a Baja Trucks. Or in my field of expertise, do you see only intense-bright lighting in a Museum?


Hey, I must be a bike lighting expert as I still have an OEM 35 watt bulb on my XR4. It really does an excellent job on my front fender, can see every scratch!
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Old 05-29-2013, 10:54 AM   #8692
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After spending the whole morning exploring/lost, I headed home instead of making the trip.
Try this one: http://binged.it/ZeFk7Y done it few times it's a nice section with volcanic rocks with some uphill. It connect u straight to CampWood rd via 665.
It look something like this: ( DOD here Da man).

It could be deteriorated than that dunno, I haven't been there in 2 years. But it's time to pay this area a visit ...
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Old 05-29-2013, 11:03 AM   #8693
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I feel the same way with my SCUBA lights. The LED light is super bright, but everything is washed out white. The HID cannister lights give a really nice spectrum.

Although; when a fish gets spotted with the HID they would swim around like nothing was going on...The LED would freeze the fish like an Alien Spotlight.

I wonder if the same is true with the coyotes running across the trail at night. Better to keep them running than frozen in the middle of the road.

This is all very scientific.
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Old 05-29-2013, 11:15 AM   #8694
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Thanks Ed I am trying to connect this where Fr21 intersects 702



& come out on H ranch Rd. & 97?
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Old 05-29-2013, 11:30 AM   #8695
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Originally Posted by cyberdos View Post
You obviously know lots more on the technical side than I do.
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Originally Posted by mefadv View Post
You are using terms here that most people have never heard of... or care too.
We all tend to be informed about the things we both do for a living and also have some passionate interest in! GNSS (GPS) is another for me. I really like working with some of this stuff.

Quote:
Originally Posted by cyberdos View Post
All I know is what my eyes tell me but I have one question. You say HID's are the best but then say that the spike in blue on the LED's are bad. Don't the HID's have the same issue? I've never liked HID lights because of the blue that they throw off.
HID is a generic term and they are *not* all created equal. Most tend to favor blue (not so good!) but they have a very different spectra than LED's have. They do have multiple spikes that incandescent in general don't.

I was looking for some spectra of HID's... most of what I found readily was for "grow lamps"... go figure.

These aren't the best examples but I didn't feel like spending much time digging. I used to have a lot at my fingertips but it's been a few years.

!!!There is so much variation between the products within a given technology that I make no claim that these are representative of the entire group of products within the given technology!!!

These just give a general "feel" for how the spectra are very different between the technologies...

HID:




LED:




Incandescent:

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Old 05-29-2013, 11:54 AM   #8696
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I feel the same way with my SCUBA lights. The LED light is super bright, but everything is washed out white. The HID cannister lights give a really nice spectrum.

Although; when a fish gets spotted with the HID they would swim around like nothing was going on...The LED would freeze the fish like an Alien Spotlight.

I wonder if the same is true with the coyotes running across the trail at night. Better to keep them running than frozen in the middle of the road.

This is all very scientific.
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Old 05-29-2013, 11:58 AM   #8697
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Thanks for all the good info pertaining to the different lights. It definitely helps understand things better.
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Old 05-29-2013, 01:10 PM   #8698
AZ TOM
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I'm still just confused
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Old 05-29-2013, 02:22 PM   #8699
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I'm still just confused
someone should shed light on this issue.
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Old 05-29-2013, 02:47 PM   #8700
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For another way to think about it.... Ideally lights output spectrum would be wide and flat covering all the visible frequencies (colors) and with equal intensity across all of them. Using audio as an analogy, a good music system has the same output at all frequencies you can hear, plus some, 20 Hz to 20,000 Hz. If the typical LED light were music you would only hear the bass. Kinda like the overpowered crappy setups you hear at stop lights...
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