Best beam shape for LED lights???

A direct line into a LED light manufacture fell into my lap yesterday, and I have to opportunity to develop a better light for our use if one is needed. All of the bike lights I've seen guys use, ready built or DIY, have a lens creating a round beam. It doesn't seem optimal to me. Cars got away from that decades ago, and the problem I see is light wasted too low and too high along with the safety issues of blinding oncoming traffic and not seeing animals or people as well coming from the sides.

I really like the halogen fog light I use on my ebikes, which has spread of something like 120° wide and 20° vertical. On a bike it's a bit short on the vertical spread, because the mounting height is more than double it's design use location below a car bumper, but it works quite well.

Am I correct in thinking we need LEDs with an oval beam? It seems like a no brainer for a single LED light like their 10W Cree. I also like their 5 LED light using 3W Cree's. Is 5 horizontal LEDs each projecting a round beam create enough approximation of oval. The 27W light with nine 3W Crees laid out in an oval look pretty sweet too for $7 more.

I started asking about a spread beam light such as a fog light design, since they have so many different models, and instead of directing me to a specific product they start talking about new lens molds. I fall into the camp of preferring to repurpose instead of redesign, but hey if they want to make whatever I want, then why not? I don't know exactly what that is though, so your input is welcome. In the meantime, I'm getting some samples in route. Direct shipping is arranged already, so this might just fly in time for Christmas if an existing model works.

John

Personally I find a round beam a real pain. I made a simple headlight using a Luxeon 3W LED and lens and although it's bright enough for street riding around here the beam is all wrong.

What I'd like is either an oval beam, or better still a beam that is oval but with a flat top, one with even light coverage over a fairly wide area. I'd like to have a lot of peripheral light, to show up the road around as well as in front, as that makes life a lot easier when riding on some of the windy lanes around here.

Be interested if you can find a source for oval beam lenses, as at the moment the LED people seem to concentrate of the torch/flashlight market, it seems..

Thanks for confirming what I was thinking. The halogen fog light I use is almost perfect, and just a touch more vertical spread would do it. This manufacturer is fully into LEDs excluding bike lights, everything from streel lamps, to a range of auto and marine lights, as well as LED lights for the home. They brought up the idea of a new lens in my first day of contact, so they seem eager to make what is needed as opposed to just what they think is needed, so let's define the beam we want.

Maybe part of the issue is the way LEDs project the light from a flat surface as opposed to a bulb, making the issues of lens and reflectors totally different. The 5 LEDs in a horizontal line lamp may be the easiest route, and that 15W lamp is one of their cheapest. Could 5 overlapping beams in an arc, each with a 30° spot lens for each LED be the best starting point.

John

John in CR said:

Thanks for confirming what I was thinking. The halogen fog light I use is almost perfect, and just a touch more vertical spread would do it. This manufacturer is fully into LEDs excluding bike lights, everything from streel lamps, to a range of auto and marine lights, as well as LED lights for the home. They brought up the idea of a new lens in my first day of contact, so they seem eager to make what is needed as opposed to just what they think is needed, so let's define the beam we want.

Maybe part of the issue is the way LEDs project the light from a flat surface as opposed to a bulb, making the issues of lens and reflectors totally different. The 5 LEDs in a horizontal line lamp may be the easiest route, and that 15W lamp is one of their cheapest. Could 5 overlapping beams in an arc, each with a 30° spot lens for each LED be the best starting point.

John

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The multiple LED array would probably work, I have a feeling that this is what some of the night riding mountain bike people do. The other option might be to mould a lens a bit like a car headlight, with a series of vertical bar lenses to spread the beam horizontally. Not sure if it would work or not with an LED, but I think it might do. I think I've got an old bike dynamo headlight somewhere, that I'm sure had a lens like this. I might dig it out and see.

- weatherproof
- wide operating voltage ( to run form ebike pack 36 to 100 v)

focusable lens from wide beam to narrow with a twist or stiff telescoping head.
Low/high setting.

in the mountain, we use 2 lights. One is mounted on the bike and one on the forehead, or helmet. A wide beam like car fog lights would be ideal to mount on the bike. On the helmet, best is a variable flood to spot round light as light weight as possible. Mountain trails are very dangerous at night, even with the best light one has to slow down considerably.

My handlebar lights are incandescent and the sealed beam type as on a car headlight, they cast a spot beam from the center but the edges of the beam are diffused for side illumination and visibility. My helmet light is an led round beam spot so when I glance at a cager they usually see me, sometimes it takes a double-take until our eyes meet and I'm seen but it is very effective in most situations. Viewed directly, the beam is a circle; but at an angle,as when looking at the road surface- the beam looks like an oval, which illuminates the area directly in front of the bike out to about 100 ft. on high setting. Multiple led lights can combine 2 or more "circle beams" to create a pattern beam of the designer's choosing. Modern vehicle headlights are "projector beam" where a lens is used to focus the light in a narrow beam with side enhancement having less blinding effect for other drivers, when adjusted properly they appear to "flash" on bumpy roads due to the flat-topped oval beam pattern. When not properly adjusted, they are blinding to other drivers and very irritating.

So I flash drivers once or twice with the helmet light, and if that doesn't work, they get a 600 lumen blast from the handheld Shurefire M6, which lights up the interior of their car like a night sun from a police helicopter. That usually panics the most stubborn idiot into stopping before they hit me, but nothing can be done about getting blind sided by the notorious texter.

These are 4 of the best candidate that I selected. I think the top left may be the best candidate, especially if they can just pop in 3W LEDs in place of the 1W. The 1W may be ok for a low speed bike. If I get these in next week, and any of the stock units make sense, just in time for stocking stuffers may work out.

Ypedal- These are all set up for 10-30V, so a DC/DC converter that handles all accessories is the best bet. They're all IP67, which means dust proof and water resistance to 1M. The other options all come on bike lights that already exist.

I love getting new led lights so yea if you get some id love to make a purchase.

I have that 27w one in the corner on my bike. Two of them, they are waaaaaay bright, but super unfocused.

I'm currently using a pair of lights like these:


One is round for a high beam and the other does a line for low beams. The low beam works ok for lower speeds but not so good above 30.

Right now I have it set up where one or the other is lit but I may try it with both on for high to get better spread.

I do think that oval is the way to go.

Gary

As soft and halogen-y as possible.

The magic shines for example, have such a pinhole spotlight effect that i have to constantly move them around to prevent blinding drivers or pedestrians. Also, things fall into my blind spot very easily.

A halogen doesn't do this, i remember my oldschool 'cateye' lights never needing adjustment as they had quite a nice flood going on. I ditched those though because they chugged batteries ( this was of course before i found out about eBikes )

Farfle,
What do you mean by "unfocused"? It seems like you're saying that's bad, or is the result varied light and darker patches? Do you mind if I ask what you paid for them?

GrayKard,
On yours with the diffusion lens for low beam, is it on the right track but just needs more power and a more oval spread?

Neptronix,
Your explanation nailed what I'm after. It's seems like a very bright well focused tight spot would make things harder to see outside of that spot despite being fairly well lit, because the bright spot is so bright that your eyes react to it. For softness, do you think that has something to do with color temp?

All,
Here are 2 different lens, both claiming 60°flood/30°spot. On lights you've liked better was the lens more like the one on the left? It seems to me now that LEDs are getting powerful enough that we can get enough light with the diffusion of a car headlight type of lens. That makes me lean toward the one on the left. I've got a few fairly low power LED flashlights, so just e LEDnoob. What do you guys with LED know-how think?


They just came back to me asking if this "oval flood" is what I'm after, and I said YES. I checked my halogen and it draws a bit under 4A, so it's a 40W light, and on the road I feel good for 25-30 at night with it. With a minimum advantage of 4:1 for light output per watt of LEDs vs halogens, 15W or more of LED power in this oval shape should be sweet. We'll see if I can resist getting too carried away, since they do have a 180W LED light bar.

I think the best beam shape is what has been progressively come up with for cars and such--the best I've used myself mostly appears as a cross. A wide beam with a bright center bar, which lights up the road's entire lane (plus some) at whatever your "optimal" distance is based on yoru typical speeds, and a "tall" area in the center that lights up the center of your lane both closer to you and farther away, and does a good job of adding some light to roadsigns and whatnot far enough away to read them usefully.

Also, the larger the front lit surface of the whole lamp assembly is, the better the visibility for others to see you, as well as not having a blinding point source. THis should also help others be able to more accurately judge your distance from them in intersection approaches and whatnot, as a point source or small light makes you look a lot farther away than you really are, and lets them think they can go even when it's not really safe to do so. (not true of everyone, but I think a lot of people judge by lights rather than anything else when they just glance around for other traffic, rather than other cues taht might give them better info).


EDIT: Ah; here's a pic of the headlight shining on a wall; I don't think I have one of it shining on the road.

John in CR said:

Farfle,
What do you mean by "unfocused"? It seems like you're saying that's bad, or is the result varied light and darker patches? Do you mind if I ask what you paid for them?

GrayKard,
On yours with the diffusion lens for low beam, is it on the right track but just needs more power and a more oval spread?

Neptronix,
Your explanation nailed what I'm after. It's seems like a very bright well focused tight spot would make things harder to see outside of that spot despite being fairly well lit, because the bright spot is so bright that your eyes react to it. For softness, do you think that has something to do with color temp?

All,
Here are 2 different lens, both claiming 60°flood/30°spot. On lights you've liked better was the lens more like the one on the left? It seems to me now that LEDs are getting powerful enough that we can get enough light with the diffusion of a car headlight type of lens. That makes me lean toward the one on the left. I've got a few fairly low power LED flashlights, so just e LEDnoob. What do you guys with LED know-how think?
View attachment 1

They just came back to me asking if this "oval flood" is what I'm after, and I said YES. I checked my halogen and it draws a bit under 4A, so it's a 40W light, and on the road I feel good for 25-30 at night with it. With a minimum advantage of 4:1 for light output per watt of LEDs vs halogens, 15W or more of LED power in this oval shape should be sweet. We'll see if I can resist getting too carried away, since they do have a 180W LED light bar.

Click to expand...

I have the 30* one on the right, and by not very focused I mean its more like a 60. It illuminates a very broad area of light. Compared to the headlights on my gfs ford explorer they light up a patch about 2x as tall, and about 3x wider which makes ri ding with it unpleasant for oncoming traffic oh, I paid about 80bucks shipped for the pair on amazon.