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Discussion Starter · #1 ·
So I got this crazy bright red led flashlight to use as a rear light for my bike. It's awesome except for the beam pattern. It's super super narrow. Is there any good way (lenses/reflectors/etc) to make it a little bit wider w/o wasting a bunch of the cager-blinding lumens??? (and no I don't actually want to blind the motorists... usually:p )
 

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One option to try is to mount (tape) a small-diameter flat reflector (maybe 1/4-1/3 the diameter of the flashlight outer lens/glass - maybe less) in the center of the flashlight outer lens/glass. The flat reflector could simply be a small "disk" of aluminum foil (use the shiny side as the reflector). The goal would be to reflect light back into the concave reflector of the flashlight at off-angles so it is reflected back out at off-angle to give you a wider beam pattern. You can test disks of different sizes -- measuring the beam diameter (and illumination pattern) on a dark wall without the disk and with disks of different diameter. Another option is to tape a piece of clear plastic, like maybe the top of a clear clamshell food container or maybe even a disposable water bottle, over all of the flashlight outer lens/glass to get some scattering for a wider illumination angle.

PS Yet another option with the disk retro-reflector is to give it some curvature - so that it's a bit convex from the point of view of the light leaving the flashlight - by wrapping the foil around some segment of a sphere - like a piece of a ping pong ball or something about that diameter.

PPS Yet another option is to tape foil across the upper or lower 1/3 of the outer lens, or maybe both, to try to get a wide angle beam in the viewing range that drivers are likely to be - rather than sending wide-angle light up into the sky or down into the ground.
 

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Discussion Starter · #4 ·
But they're not as bright as this one... it was ten dollars too!!
 

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Discussion Starter · #5 ·
PERFECT!! I cut up the lens/reflector thing from an old broken blinky tail light. It had a circle piece that fit perfectly over the flashlight w/ a little piece of mtb tire innertube. It spreads the beam out perfectly and it's still super bright. You can barely see the little blinking one on the seat post now. Ordered some rechargeable 18650's and a charger. So for <$30 (the price of the blinkey light that this thing dwarfs) I've got a tail light that's probably almost as bright as that crazy $150+ one.
 

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MWPDX said:
So I got this crazy bright red led flashlight to use as a rear light for my bike. It's awesome except for the beam pattern. It's super super narrow. Is there any good way (lenses/reflectors/etc) to make it a little bit wider w/o wasting a bunch of the cager-blinding lumens??? (and no I don't actually want to blind the motorists... usually:p )
Deal extreme? link?
 

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Discussion Starter · #7 ·
mbaha said:
Deal extreme? link?
How'djya guess? :p

Flashlight: http://www.dealextreme.com/details.dx/sku.20333

Batteries: http://www.dealextreme.com/details.dx/sku.19770
(I think. They have about a million diff. ones that all look the same to me)

And the charger: http://www.dealextreme.com/details.dx/sku.6105

Haven't recieved the charger and batteries yet so I dunno about those. I just used some regular cr123a's I had from another flashlight.

Also, I've been wondering... is there a reason nobody talks about deal extreme around here?? It's all over that *cough cough* other bike forum *cough cough*.
 

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oh man I have that same light in white. it's a retina blaster.

hmmmm

/ count me in as a mjor DX fan. I've shilled it here many times.
 

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+1 on DX. I have one of their P7 flashlight for my commutes, and that thing absolutely rocks! (combined with a PB superflash)
 

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You'll see all kinds of people talking about DX on the MTBR lighting forums. I'm considering doing exactly what you did, for my commuter. Although I'd probably leave the narrow beam. I figure the only people that need to see the beam are directly behind me, so it doesn't need a wider pattern.

I wish that light had a blinky mode!

I'm thinking I'll get the smallest flashlight they have with an SSC P7 and use that as a front light (my current one is way too weak). I have a couple of 6 cell 7.2v NiMh batteries and a quick charger from a r/c car. I want to run that to both the front and tail lights so that I can just charge one battery, once a week.
 

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Discussion Starter · #11 ·
JohnnyTooBad said:
You'll see all kinds of people talking about DX on the MTBR lighting forums. I'm considering doing exactly what you did, for my commuter. Although I'd probably leave the narrow beam. I figure the only people that need to see the beam are directly behind me, so it doesn't need a wider pattern.

I wish that light had a blinky mode!

I'm thinking I'll get the smallest flashlight they have with an SSC P7 and use that as a front light (my current one is way too weak). I have a couple of 6 cell 7.2v NiMh batteries and a quick charger from a r/c car. I want to run that to both the front and tail lights so that I can just charge one battery, once a week.
I was thinking the same thing w/ the beam width but now I'm thinking the people who are gonna be right behind me are gonna be other cyclists. It really is narrow. I experimented w/ pointing it at diff. angles (up and to the left, basically). If I point it straight back, it makes a pretty large 'blind spot' once you get about within about 10-20 feet from the bike. If I point it up and to the left to light up the blind spot, you can't really see it from super far away. YMMV, of course.


As for the blinky mode, after seeing how bright it is, I think it's best as a steady light. I like the combination of a small, cheap (but more expensive than this light for whatever reason) blinky light to get their attention and the bright steady light so they can tell where I am until they pass me. That's just me though.
 
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