Rear Red LED vs rear filtered White.

[marcopolo]

I've been thinking a lot about rear lights recently. I fount an old WHITE star mounted luxeon 3 LED in the garage and placed a red filter infront of it and it looks to me orange-ish.

What are poeples thoughts on using filtered White LED's vs using dedicated red LED's under a red diffuser?

Is it even legal to use a red filter on white LED?

What about extra red/purple plastic film to turn it a bit more red?

Marco.

 

[znomit]

What are poeples thoughts on using filtered White LED's vs using dedicated red LED's under a red diffuser?

Ideally use a red LED, much more efficient. Note the Vf is much lower on reds so check your driver is ok with it.
The DX red crees are good value.

 

[hit4six]

I've been thinking a lot about rear lights recently.

snap.

I've tried the red p60 dropins from Kaidomain and yes, they are much more effective than white with red filter. I've ordered the new red torch from Dx.

If you get the right colour with a filter and it is bright enough for you, maybe the white led it will do. Red led sounds like a better choice though.

 

[65535]

Make sure you diffuse the light. Red leds are very harsh without a diffuser.

 

[Baulz]

Ideally use a red LED, much more efficient. Note the Vf is much lower on reds so check your driver is ok with it.
The DX red crees are good value.

Any suggestions on a driver with flashing mode for the red Cree's? Looked around at DX and could not find anything suitable.

 

[mkrabach]

Maybe something in my site might give you some help. Although some of the LED drivers/regulators seem to be out of stock at DX. I tried several combinations of white and red LEDs and drivers.
http://www.kayakaccessri.info/krabachwebsite/bike_light/bike_light_project/intro.html
The red flashers are at the bottom of the contents.

 

[BillyNoMates]

I'd second the suggestion that a red LED is better than a filtered white - why go to the trouble of creating a broad spectrum to make an emitter look white then filter of 90% of the light to get red?

I have been using a lamp based on 9xRebel Neutral White (80lm bin) for my regular commute. While this light is extremely bright, I have noticed that there is very little light in the red portion of the spectrum - reflective road signs light up from 100's of metres away, but rear red refectors on parked cars are bearly noticable by comparison.

I'm currently putting together a stupidly bright rear light at the moment - it uses 5xRebels behind a normal clear optic - 15degree. I am using a buck-boost driver (primarily desgined for white LEDs but it works fine with the lower Vf of the red LEDs - works in buck mode all the time with a single Li-ion cell). I have a feeling that this may be too bright to use on the road - I will probably have to turn down the drive.

 

[pe2er]

To me also, it makes more sense to use a red LED. I'm currently constructing a tail light based on the this red 1W LED spot from which I recover the LED and driver. It will be combined with this Diffuser/ Lens, also from DX, and the reflector from a red blinker.

Power will come from the same battery that I use for my front light.

:wave:
*

 

[BillyNoMates]

I'm currently putting together a stupidly bright rear light at the moment - it uses 5xRebels behind a normal clear optic - 15degree. .......... I have a feeling that this may be too bright to use on the road - I will probably have to turn down the drive.

Well I haven't quite finished yet, but I got to the point where I can mount the driver and LED board in the case I've been machining out of a block of Aluminium, and after my earlier post I was inspired to give this super powered baby a run at full steam......

I was right it is way, way too bright to be of any use as a rear light !!! >400lm output from a red led cluster is totally insane. I'll take some beam shots before I wind the juice down as a reference.