This occoured to me last night on my way home from a ride, as I went under a short tunnel...
Why are manufacturers wasting so much of their light output by having a circular beam pattern? I was lighting up the roof of the tunnel just as well as the floor in front of me (Yes they were correctly aimed!) and I reckon 1/3 of the output from the light is just wasted up there in the sky. Now I can see that MTBers need some 'upward' lighting for sharp climbs etc but not THAT much!
i.e. - Take a car low beam, which has most of it's ouput aimed neatly at the floor
And whilst on the subject of low/high beams, why in the age of multiple LED lights are we changing power by dimming the bulbs? Why not have a nice even flood/low beam from half the LEDs, then use the other LEDs as a more focused high beam (again, like a car)
And that's it, just 2 settings is all you need: A nice bright flood near the bike for the twisy bits, with no wasted light, then bang the high beam on for the faster, straighter stuff, so you can see into the distance. It's gotta be my ideal light, at least.
Just a thought.... 🙂
fair comment
iirc that is what light and motion have done with there Seca lights
And whilst on the subject of low/high beams, why in the age of multiple LED lights are we changing power by dimming the bulbs?
Because it's way more efficient to dim the LED.
The other stuff though, the shape of beams is because most LED manufacturers are just using pretty simple optics or conical reflectors. If you look at B&M dynamo lights, they use a cunningly shaped reflector to make a perfectly shaped beam of light for road riding. They are very neatly done. I don't know why mountain bike light makers haven't done this.
You obviously want some upward pointing light if you ride in trees or anywhere else where there might be things at head height.
Joe
Quite a bit of my route is under trees so I need some upwards lighting to see where branches are.
iirc that is what light and motion have done with there Seca lights
That is neat, looks very well done, it looks kind of similar to what the Busch & Muller ones do. The "brand L" comparison on their site makes lupine lights look very undeveloped for something so jolly expensive.
Joe
Because it's way more efficient to dim the LED.
What, more efficiant than turning half of them off? Surely 50% power dimmed is just the same?
And I'd imagine it would be simpler electronics if there was no dimmer too....
A nice bright flood beam, hit the switch and add a nice bright high beam. No messing. Gotta be good, surely?!
🙂
I tend to have my light pointed as far down the trail as I can reasonably see, by which point, a bit of upwards pointed light is useful for spotting low branches, bushes, etc etc
Silva make a light that has a triangulated beam pattern - so the light gets shone out in front of the rider but down to the ground...3 'spots' that make up a triangle-shaped beam.
Light & Motion Sica (I think) has a similar beam pattern and I think the previous top-end Use Exposure light had a similar beam pattern but not quite as obvious as a triangle...
Some manufacturers are designing a better directed beam but I guess this extra design costs money and therefore increases cost to buyer...lights are already rather pricey (unless you go the DX path) so adding to the cost will put more people off.
What, more efficiant than turning half of them off? Surely 50% power dimmed is just the same? And I'd imagine it would be simpler electronics if there was no dimmer too....
LEDs produce significantly more light per amp at 50% power than they do at 100% power. So if you put in 50% of the power, you get something like 60% or more of the amount of light.
I think the complexity of the electronics is in having a constant current circuit. I don't think dimming massively increases complexity (it is just sticking a different resistor into the circuit somewhere basically).
Joe
Thanks Joe, nice explanation
🙂
to do PP s idea needs either 2 drivers or a much more complex driver
as just switching leds in and out is risky for the leds and the driver
lets say 4 leds are running off one driver the driver is sending 14 volts and 1000ma to the string now if you switch off 2 of the leds the other 2 will get the full 14 volts for a time while the driver can react to the sudden change .
so much more circuitry needs designing in or 2 seperate drivers to allow the switching in and out of half the leds so adding cost either ways .
Raw lumens are relatively cheap, custom designed/engineered reflectors and optics aren't.....
Trout, fair enough, that shoots my simplicity idea down! 🙂
Although I still reckon 2 seperate beams would be worth trying.
my sister has ayups..
that is the cool thing about their twin lamp system - angle one side down and one ahead - same with the helmet lamp
plus wider angle beam for handlebars and spot for head - ayups are a great system - very flexible
My old Hope Vision2 puts out a silly wide beam pattern which lights trees above my head and bounces off the clouds. Probably about 40% of the light is wasted. This is why I use a Stella on my helmet which has a very focussed beam pattern and compliments the Hope perfectly.
Neither of them are very good on their own though.
Funny, I've been thinking this for some time - I was even considering trying fitting a small (plastic) mirror to the top of my light to angle it down just to see how much difference it made when riding.
Ahh, good to see I'm not the only one that thinks like this then..
🙂
you can have a wide flat beam using eliptical optics , works very well
with no wasted light up in the trees also good for cheeky trails 😉
Just always suprised that most companies don't seem to be doing it - ok I can understand that there's cost associated but I wouldn't have though that it was fundamentally all that complex since it's just simple geometry what with light being helpful and going in straight lines 🙂
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Picture of the Seca beam pattern from the Light & Motion website.