Red LEDs behind red lens?

I want to replace the incandescent brake light bulbs with LED, but the
only LED bulb available (style 7443) has red LEDs. And my lens is red.
With a red bulb behind a red lens, will it be bright enuf?

Hamish

"Hamish" > wrote in message
m...
>I want to replace the incandescent brake light bulbs with LED, but the only
>LED bulb available (style 7443) has red LEDs. And my lens is red. With a
>red bulb behind a red lens, will it be bright enuf?
>
> Hamish

Answer is "maybe". The lens is red because it filters out almost all other
frequencies of light except red. Attenuation is minimum, but not zero.
The other part of maybe is that it also depends upon the strength of the
red leds themselves.

Easiest is try it and see.

Hamish wrote:
> I want to replace the incandescent brake light bulbs with LED, but the
> only LED bulb available (style 7443) has red LEDs. And my lens is red.
> With a red bulb behind a red lens, will it be bright enuf?
>
> Hamish

Probably not, but not becuase of the lens but because LED "bulbs" just
aren't bright enough. HAven't found one yet that works worth a crap,
although I haven't tried any of the $40+ ones.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Hamish wrote:
> I want to replace the incandescent brake light bulbs with LED, but the
> only LED bulb available (style 7443) has red LEDs. And my lens is red.
> With a red bulb behind a red lens, will it be bright enuf?
>
> Hamish

IMO, they will not be seen from outside of a very narrow cone
and won't be bright enough unless the tail light lenses are
specifically made for leds.

Hamish > wrote:
>I want to replace the incandescent brake light bulbs with LED, but the
>only LED bulb available (style 7443) has red LEDs. And my lens is red.
>With a red bulb behind a red lens, will it be bright enuf?

No, it won't be, but it has nothing to do with the color. You _have_
to use a red LED if you have a red lens.... no other color will work.

But, you'll find the LED replacement bulbs in general have very poor
dispersion and are harder to see than conventional incandescent bulbs.
They're getting better all the time, but wait another few years before
you go that route.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

(Scott Dorsey) wrote in news:gnnid2$o3c$1
@panix2.panix.com:

> Hamish > wrote:
>>I want to replace the incandescent brake light bulbs with LED, but the
>>only LED bulb available (style 7443) has red LEDs. And my lens is red.
>>With a red bulb behind a red lens, will it be bright enuf?
>
> No, it won't be, but it has nothing to do with the color. You _have_
> to use a red LED if you have a red lens.... no other color will work.
>
> But, you'll find the LED replacement bulbs in general have very poor
> dispersion and are harder to see than conventional incandescent bulbs.



Ain't that the truth.

Some time ago I was in heavy traffic behind this young kid in one of those
Rice-a-roni Civics that sits a bouncy 1/16" off the pavement.

At first I thought I was not paying enough attention after having almost
rear-ended him a couple of times, but then I realized the near-misses were
due to his combination of Altezza-type aftermarket taillamps and LED brake
lamp "bulbs". Those LEDs (eight per "bulb") were virtually invisible, and
this in early-morning sunlight. Bet he thought he was super-kewl, though.



> They're getting better all the time, but wait another few years before
> you go that route.


Maybe ten years...


--
Tegger

> You _have_
> to use a red LED if you have a red lens.... no other color will work.

I just did an experiment with a white LED flashlight,* and indeed, a
red light emerges from a red taillight lens.

It's attenuated quite a bit. I've seen dimmer taillights in cars that
perhaps had sorry electrical connections or a poor choice of bulbs,
but still, it isn't nearly as bright as a properly selected and
functioning incandescent taillight.

I guess the physics interpretation is that the LEDs might be more
narrowband than incandescents but aren't lasers either; and the
taillight lens is colored but isn't exactly a steep-sided, narrow
notch filter.


--Joe

* Talk about the best thing you can do for safety for $1.99 at the
discount tool bin near the cash register... they're small enough and
cheap enough to have one or two in every car, and are quite bright.

"Ad absurdum per aspera" > wrote in message
...
>> You _have_
>> to use a red LED if you have a red lens.... no other color will work.
>
> I just did an experiment with a white LED flashlight,* and indeed, a
> red light emerges from a red taillight lens.


I wasnt sure what he meant by that post either, but didnt challenge it.
There should be some attenuation, since "white" light is composed of a
distribution
of wavelengths, essentially all of which but red would be filtered out.

Even 'pure' red light would suffer some attenuation, but not as much as
white.