LeeG

I saw one of these recently, very sharp cut-off on the edges. Someone should be able to make something like this for dyno powered headlights.

unterhausen

the cheapest dyno light I have, the B&M Lumotec Lyt, has a square beam. Until I got used to it, it made me laugh. I don't think it's what you really want in a beam, but it's interesting that they have optics for a flashlight that makes a square beam.

Jaywalk3r

Most LEDs are square, so if they are very well focused, the resulting beam is also square. The Surefire L1 comes to mind as one example.

unterhausen

the emitter itself might be square, but they usually put a dome on top

Jaywalk3r

I'm sure that's taken into consideration when the optic is designed for the emitter model. It's interesting how they can focus the light so well to recover the emitter's original shape.

cyccommute 

It's not all that hard to project any shape you want. My daughters had lamps when they were little that projected stars and fish and I've seen ones that projected giraffes. Since the bulbs used were just regular 25 to 60 watt pear shaped incandescents and unfocused, I doubt that they were recovering the bulbs original fish or star or giraffe shape.

There's nothing magic about projecting any shape you want. If you've been to a movie since about 1895, you've seen a square(ish) projected shape that doesn't use a emitter with a square shape but manages to make it square anyway. It's the optics that make it square just as the optics in this flashlight make it square as well. LED emitters are going to emit in a hemisphere just like any other light source. You bend it to your will with the optics.

cyccommute 

I went looking for pictures of the beam and was struck by 1) the absolute hamhanded use of photoshop and 2) how the world would look like crooked picture all the time if using a square beam. It would make corners feel very weird.

PaulRivers

It puts the light where you need it the most -


It ends up square on the edges because of the power and light output limitations of a dynamo and older tech / a cheaper light. With something more advanced and more expensive, it just has a cutoff -

Jaywalk3r

That may indeed be true, but in the case if high quality, tightly focused beams, it is just retaining the LED's original shape. A high quality optic can collimate the light emitted from the LED very, very well, so that shape isn't lost. If you examine the beam very carefully, on a uniform matte white surface, you can even see the details of the LED die in the beam.

unterhausen

yeah, the lyt wouldn't be my first choice for fast riding, but it's a great light on my commuter. Actually, I did use it off-road this past winter and it worked fine.

cyccommute 

I doubt that very highly. They are using a mask...just as you would for any other application where you want to project a square beam. None of the pictures that I've seen on Google images...the ones that aren't obvious photoshops...show any kind of pattern whatsoever. I haven't seen one of the lights in person but I really doubt that you can see the LED die in the beam. Nor would you probably want to. Projectors of all kinds have far better optics than this little light can use and you can't see any details of the source from them and, if you did, it would be detrimental to what you want to do with a projected light, especially if you want to project the light through film stock for example.

Jaywalk3r

Find yourself a Surefire L1 and see it for yourself.

Bushnell might, I don't know. But that isn't how high-end portable lights obtain a square beam. In fact, the square beam is the price that has to be paid for excellent collimation. A round beam would be considered better by most users, but that would come at the price of decreased throw.

unterhausen

you can definitely see the image of the 4 emitters from the multi-emitter leds in people's beamshots. Not sure what that proves though. I would guess bushnell is using a shaped reflector/optics, but you could tell if you saw one in person

zacster

My bike light puts out a square beam when zoomed in, and it is squared off when zoomed out.





You can't see it in the picture, but zoomed in you can see a grid pattern in the intense center.

Richard Cranium

I know what everyone is talking about - but I don't really care. Whether or not a single emitter or light produces a square beam is only thinking about the "lighted area" issue with a simple perspective.

Bicycle lighting needs are considerably more dynamic than that of an auto or motorcycle. But even at a simple level - most cyclists understand their lighting needs change with their current speed and current surroundings.

Maybe square is better. But sometimes only a lot more will do.

At least some manufacturers address this issue by employing dual-beam head lights. I know I'm just an old school "Richard Cranium" - but I'm going to use a high powered flashlight to get the "beam I need" when going somewhere fast in the dark.

I'm sure there are some $300 plus lights that just work by changing power settings - why not mention some of those lights?

cyccommute 

Huh? The uniqueness of the Bushnell Square Beam flashlight is, well, the square beam. I've looked at a lot of beamshots from a lot of lights for a lot of years and this is about the only one I've seen that has a "square beam". Even the Bushnell Square Beam isn't all that square in a real world picture (see here).

Jaywalk3r

This is one of those cases where white wall beam shots are required to reveal the details we're interested in.

Like I said, I'm not familiar with the Bushnell. The square beamed lights I am familiar with, such as the Surefire L1, simply utilize optics that collimate the emitted light well enough that the square shape of the emitter is retained. It certainly isn't added back. It's a consequence of excellent collimation.