Line between seen and being seen

[Toddorado]

Hey all - after shopping around for a while, I'm unclear as to how lights are rated. Some are in lumens, some in candlepower, some in watts (a measuer of input, if I'm not mistaken). I'm looking for output that is less than a car headlight, but enough to see 15 feet in front of me without squinting. I currently have a CygoLite Rover, but do not like carrying the water bottle battery. I have a Cat Eye EL500 on order and will see how it does, but was wondering what the readers of this forum thought? Thanks for any advice.

EDIT: SEEING and being seen" :o

[BarracksSi]

Comparing bike lights to car headlights is a strange comparison to make, mainly because of the beam pattern & cutoff requirements imposed by the DoT on car headlights.

A bike light can output less light than a car headlight, but above the car light's cutoff (which, if aligned correctly, should be about bumper height for its entire "throw distance"), the bike light will seem brighter.

To be useful as a "be seen light", a bike light has to be pretty darned bright, IMO. It'll have to compete with headlights, taillights, streetlights, and all the reflections that they make on parked cars, store windows, etc.

If you only need to see in the dark, you could probably get away with a little less, although it never hurts to have more. If you're on a surface that's poorly lit, a really bright light can be annoying & blinding to oncoming cyclists, joggers, etc.

[ad6mj]

A lot depends on where you are riding. If you are in the country with no lights around, almost any light will make you seen. It also doesn't take much to see either. Inareas with lots of lights, it takes more to standout.

[operator]

To be useful as a "be seen light", a bike light has to be pretty darned bright, IMO. It'll have to compete with headlights, taillights, streetlights, and all the reflections that they make on parked cars, store windows, etc.

If you only need to see in the dark, you could probably get away with a little less, although it never hurts to have more. If you're on a surface that's poorly lit, a really bright light can be annoying & blinding to oncoming cyclists, joggers, etc.

You have it completely opposite. You don't need that much light "to be seen". A white flashing LED on the front or in strobe mode + one or two running lights and you can bee seen from miles on end.

On the other hand if you want to SEE, then you're going to need something around the neighbourhood of dinotte 600L. Especially if you're going through streetlighted streets and/or rain/snow.

[BarracksSi]

Not in my experience in my traffic-congested neighborhood. Sightlines are barely hundreds of feet anyway, so standing out from the clutter is more important. Low- to medium-brightness blinkies can get lost pretty quickly.

[joshandlauri]

when we changed the clocks, all of a sudden my commute was at night, i bought a hl-el200, it was a to be seen light, I returned it and got a hl-el300, little brighter but onl a 5 foot spot in front of me and didn't feel safe over 5mph, I then made a DIY light with a 20 watt and 50 watt light and "I feel" its just a bright as a car light, a car can come up behind me and I can't tell where my light ends and theirs begins.

[ken cummings]

Lumen, candlepower, watts; The seller uses whatever terms make the light look better. Lumen measure light energy. If that light is poorly aimed it is wasted. Candlepower measure how concentrated that light is. A genuine candle at the focal point of a good reflector could give you several thousand candlepower. Like in a old lighthouse. A lower power, higher efficiency LED will tend to give you more lumens per watt then a common incandescent bulb. A high power LED may be no more efficient then a good halogen cycle bulb. . . .