Electronics, Lighting, & Gadgets - Cheap, powerful rear light?

I have come across this light, but I haven't bought one or seen one. Anyone know anything about them?

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

looks promising, nice find.

Yep, nice find.

Ok, bought one.

Dang it...just when I thought I was all set with my rear lighting, this pops up. Maybe a couple of these attach to the seat stays. :)

Just bought one of these as well - Glass Optic (http://www.dealextreme.com/details.dx/sku.5297)

tell us how it goes.
but I'm curious, why a converging lens?

I have come across this light, but I haven't bought one or seen one. Anyone know anything about them?

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

One Hour Run Time.

Way Too Short.

tell us how it goes.
but I'm curious, why a converging lens?

It's a torch, without a secondary lens it's only going to be visible from directly behind.

the 1hr run time is probably inaccurate because the power draw and run time don't add up according to the posts on DX.

It's a torch, without a secondary lens it's only going to be visible from directly behind.

then wouldn't you want a diverging lens?

One Hour Run Time. Way Too Short.

I'm pretty sure that's a mistake.

Red LEDs are usually lower voltage than white, also they claim 800mA regulated which would probably give more like 3 hours.

Personally I suspect the LED is receiving less than 800mA and runtime will be proportionally longer.

If it is running at 800mA expect dinotte levels of brightness !!

However, I'll let you know when it arrives...

:)

then wouldn't you want a diverging lens?

My thought too, the reviews are talking about setting things on fire and melting plastic, not casting a nice wide, visible from every angle beam.

Ok, here's some specs: Luxeon K2 red LED (http://www.luxeonstar.com/luxeon-k2-led-red-lambertian-75-lm-700ma-p-256.php)

Lumens 75 lm @ 700mA, 45 lm @ 350mA.
Max Continuous Current 700 mA
Forward Voltage 3.4 Vf
Dominant Wavelength 627 nm
LED Type K2
Radiation Pattern Lambertian
Weight 0.78g

Due to thermal management I suspect it's more likely to be about 500mA than 800mA.

Also all the torches I've bought from DX so far have been below the claimed power rating.

Runtime tests, volt and amp measurements to follow.....

:)

then wouldn't you want a diverging lens?

If it's converging, it has a focal point ?

depends on how you want to use it, collimator, converging and diverging lenses.
the curved mirror collimator on the light seems to give a nice beam angle from the shots on the site.

depending on the power it has, it might even be nice to use a diffusion lens on it.

depends on how you want to use it, collimator, converging and diverging lenses.
the curved mirror collimator on the light seems to give a nice beam angle from the shots on the site.

depending on the power it has, it might even be nice to use a diffusion lens on it.

Looks like it has a simple O/P reflector in it, to me.

yes, nice find. just ordered two.

$10. Free shipping. That's a find.

I've been looking for something like this -- a rear light to run on 18650 batteries.

then wouldn't you want a diverging lens?

Ok..find me one ?

not a clue.

Converging or flat lens is the norm since the diverging part is easily attained by just removing the collimator.

not a clue.

Converging or flat lens is the norm since the diverging part is easily attained by just removing the collimator.

You are going to have to clarify what you mean by collimator - this torch has appears to have a simple O/P reflector and as the LED is recessed maybe 20mm inside the front of the torch removing the REFLECTOR will have little beneficial effect.

I do have similar size ultrafire torches here and removing the reflector while wasting a lot of light allows a wider angle cone of light to be emitted - however it isn't anywhere near wide angle as a cycle rear light.

I'm hoping it will be possible to harness all the light output and direct it where required.

I'll experiment more when the torch arrives.

It may well be that better results can be achieved if the assault crown didn't block so much light.

:)

EDIT: Interestingly, I just realised that the red Luxeon LED is a Lambertian so most of the emitted light is going to go straight out the lens without touching the reflector anyway, so removing the reflector will have much less effect than it does on my white LED Ultrafire torches.

Sadly it's only one mode, which means no flashing or strobe.

Planet Bike's "blinky "Super Flash.." They are amazing.

Sadly it's only one mode, which means no flashing or strobe.

Suits me :thumb:

There are plenty of blinky lights available :)

EDIT: mine's in 'packaging' whatever that means....

EDIT: mine's in 'packaging' whatever that means....

Means it could still be another week before it ships.

if it's brighter than a dinotte tail light, it might be a good thing that there's no strobe or flash mode.
anyone who's been behind a dinotte tail light can attest to that.

solid/steady on will give drivers a better perception of how fast they are gaining on you compared to a blinking light source. one reason why I like to use 2 rear blinkies with one on flash and one set to steady.

I wish it came in a smaller packaged, it's not exactly 'small' at 30 x 132mm. For size comparison a TR-801 is only 24 x 114mm
I'm trying to work out in my head how to mount it to the rear at the proper angle, aside from mounting it on the helmet without using a rack.

if it's brighter than a dinotte tail light, it might be a good thing that there's no strobe or flash mode.
anyone who's been behind a dinotte tail light can attest to that.

solid/steady on will give drivers a better perception of how fast they are gaining on you compared to a blinking light source. one reason why I like to use 2 rear blinkies with one on flash and one set to steady.

IIRC the DiNotte is 140 lumens, which is well more than the flashlight.

FWIW, I use flashlights for my front lighting and couldn't be happier with them, but I just don't see this as being a good taillight due to runtime, mounting issues, and lack of a strobe or flash mode. Hopefully someone will come out with a self contained light to rival the DiNotte....

if it's brighter than a dinotte tail light, it might be a good thing that there's no strobe or flash mode.
anyone who's been behind a dinotte tail light can attest to that.

solid/steady on will give drivers a better perception of how fast they are gaining on you compared to a blinking light source. one reason why I like to use 2 rear blinkies with one on flash and one set to steady.

Luxeon list 3 Red K2's

LXK2-PD12-Q00 60 Lumens
LXK2-PD12-R00 75 Lumens
LXK2-PD12-S00 100 Lumens

All at 700 mA

good info.

I don't mean to hijack, but I've managed to find a green version of the red: http://www.dealextreme.com/details.dx/sku.20331

comes in blue and violet as well, but I don't see those being too useful.

how is green for a visability/be seen light?

good info.

I don't mean to hijack, but I've managed to find a green version of the red: http://www.dealextreme.com/details.dx/sku.20331

comes in blue and violet as well, but I don't see those being too useful.

how is green for a visability/be seen light?

The green would be good for the right side on a boat.

Only doctors and ambulances are allowed to use green over here.

would have loved to see an amber light, but green is the next best thing.
you can't use blue, but green is allowed here.

FWIW, I use flashlights for my front lighting and couldn't be happier with them, but I just don't see this as being a good taillight due to runtime, mounting issues, and lack of a strobe or flash mode. Hopefully someone will come out with a self contained light to rival the DiNotte....

Runtime is unconfirmed as yet.

I'll mount to the seatpost with a Fenix mount I already have.

Lack of strobe is a complete non-issue as I already have lots of blinkies and it's a legal requirement to have a fixed light here (it's actually more complicated than that a single rear blinky can meet the requirement, provided that it hasn't got a steady mode and meets the required standard -having looked I don't think one exists).

Erm...this is a self contained light to rival the dinotte.

Runtime tests to follow.......:thumb:

Runtime is unconfirmed as yet.

I'll mount to the seatpost with a Fenix mount I already have.

Lack of strobe is a complete non-issue as I already have lots of blinkies and it's a legal requirement to have a fixed light here (it's actually more complicated than that a single rear blinky can meet the requirement, provided that it hasn't got a steady mode and meets the required standard -having looked I don't think one exists).

Erm...this is a self contained light to rival the dinotte.

Runtime tests to follow.......:thumb:

How can it rival a Dinotte when it lacks the basic features of the Dinotte?

Mine was shipped on 3/7, so, Unknown, I may beat you to the initial tests.

I think this may be a super cheap option to a DiNotte with a little modification (new driver with modes). The form factor is large enough to accommodate modification.

Only question is how well it puts out light behind the bike.

I, like Unknown, have flashy/blinky rear lights. This would be great steady. And simple math reveals the runtime SHOULD be well over an hour.

Waiting patiently,

pdxsteve

How can it rival a Dinotte when it lacks the basic features of the Dinotte?

One man's 'basic features' are another man's 'annoying never to be used options'.

:D

Mine was shipped on 3/7, so, Unknown, I may beat you to the initial tests.

pdxsteve

Mine still hasn't shipped. :(

However they have shipped the lens I later ordered.

[QUOTE=AEO;8534537]good info.

I don't mean to hijack, but I've managed to find a green version of the red: http://www.dealextreme.com/details.dx/sku.20331

comes in blue and violet as well, but I don't see those being too useful.

how is green for a visability/be seen light?


From the few light studies I have read at work, green was rated as one of the most visible color lights, then blue.

The reason green is not used on emergency vehicles is that green means go to motorist.

From the few light studies I have read at work, green was rated as one of the most visible color lights, then blue.

The reason green is not used on emergency vehicles is that green means go to motorist.Funny you mention, because I heard (dont remember where) that a red light is purposely designed to be much more visible than a green because it's more important.

IIRC the DiNotte is 140 lumens, which is well more than the flashlight.

Help me out here, I've looked on the dinotte site, which rear light are you talking about ?

on a secondary research it seems I can't use green (or maybe just a strobing green) since it's for volunteer firefighters and volunteer EMS.
oh well, if DX only stocked amber.

on a secondary research it seems I can't use green (or maybe just a strobing green) since it's for volunteer firefighters and volunteer EMS.
oh well, if DX only stocked amber.

Seeing as they have red and green it's possible they will stock amber eventually :)

I'm not sure you are allowed amber over here, I think it's only allowed for turn signals.

You could always fit an amber LED ?

EDIT: thinking about it, breakdown trucks and road gritters have amber lights

amber can be used for many things here, exceptionally slow moving vehicle for one.

Here's (http://www.dinottelighting.com/manuals/200L_INST_A.pdf) the spec sheet for the 140L. Strange that it's actually 120 lumens according to their spec sheet. Why not call it the 120L? Does the 140 signify something else?

I made a taillight using two Lux I emitters running at 30 lumens each at a relatively wide angle, roughly +/- 30 degrees, and it was close to being too bright. I dialed them down to 15 lumens each, added two more emitters, and now it's perfect. I can't imagine how blinding this torch will be. I'm sure you'll have to point it downward.

I did wonder how they managed to get 140 lumens from a single red LED :)

I did wonder how they managed to get 140 lumens from a single red LED :)

Actually, a Lux III (http://www.philipslumileds.com/pdfs/DS46.PDF) can be run up to 1.4 A and gives 140 lumens for red and 190 lumens for red-orange.

I picture attaching this to my back rack and angling it down, so it casts a large red area on the ground behind me.

At least that's what I see (hope) in my minds eye. I will post picture as soon as it arrives. Nothing in the mail today....

Actually, a Lux III (http://www.philipslumileds.com/pdfs/DS46.PDF) can be run up to 1.4 A and gives 140 lumens for red and 190 lumens for red-orange.

That's going to be producing a lot of heat and efficency will be down.

Is that the LED dinotte use ?

anyone come up with a 'creative' way to mount these to the rear?
I've only figured out how to do it with my folder, using a minoura space/swing grip, but I can't use the same solution with my other bikes because it's blocked by a saddle bag.

I had thoughts about using a lock block into the velcro straps on the saddle bag, but it didn't work out too well. There's a possiblity of mounting it to the chainstay, but it's lower than ideal. So, aside from mounting it to a rear rack, I'm out of ideas, so I will think up of some more ways to mount it to the rear.