Tail light brightness

[CarlG]

Originally Posted by luckyal

are the LED's available in 6 volt and if so do you know where ?
Thanks, Al

yes

[BILL WILLIAMSON]

I got stopped by the fuzz, he owned some old car & wanted to know how I got my tail lights so BRIGHT.
Buster T. wonders if APPLIANCE WHITE would work for headlight reflectors??? Bill W.

[Bruce Adams]

Originally Posted by luckyal

are the LED's available in 6 volt and if so do you know where ?
Thanks, Al

My MAC's catalog has 6 and 12 volt LED stainless steel Taillight assemblies in all red or as red and amber, with or without license plate window which includes a white LED, for about $45 apiece.

This includes the stainless steel housings.

[Mitch//pa]

Try taking the tail lights off completely

[Napa Skip]

How to compare watts and candlepower?

Well, it's a slow evening out here in the ionosphere, so here goes:

The short answer is that there is no direct conversion between cp and watts without specifying the construction and operating parameters of the bulb.

The wattage of a blub refers to the power consumed and – for simple resistive circuits (i.e., no inductive or capacitive components) – can be calculated by any of the means derived from Ohm's Law (i.e., current in amps squared times resistance in ohms or voltage in volts times resistance in ohms, etc.).

The candlepower of a blub refers to the luminous intensity emitted by the bulb and - without getting into filament construction, blub envelope material, etc. - the luminous intensity depends on the wavelength of the emitted light, the standard against which it is measured, the use of built-in reflectors (reflective coating integral to the light bulb envelope) and other parameters. In trying to avoid some “Beam me up, Scotty” responses to this reply, the simple example is that the candlepower of a bulb that draws (for example) 2 watts could be the same as the candlepower of a bulb that draws 3 watts, or - to state the converse - two differently constructed bulbs that each draw 3 watts, could have different radiant power, that is, different candlepower.

Now, for the “Beam me up, Scotty” (technically - for the Trekkies here - “Scotty, beam us up”) answer: As you will recall from kindergarten, candlepower measures luminous intensity (in candelas, sometimes referred to as ‘candles’). Specifically, one candela is one lumen per steradian (1 cp = 1 lumen/steradian). (I don’t think they covered ‘lumens’ until first grade, and I’m certain they didn’t cover solid geometry and such items as steradians until second grade, but in the event, a lumen is a unit of luminous flux, which is radiant power tempered by the response of the human eye.) As we all know, the average Mark 1 Mod 0 human eyeball has a peak response to bright light with a wavelength of about 555 nanometers, roughly the wavelength of green light (deep red is about 700 nm and violet is about 400 nm). At this frequency (wavelength being related to frequency by the speed of light) one watt of radiant power equal 683 lumens, whereas one watt of light at other frequencies/colors - i.e., of greater or lesser wavelength - will equal fewer lumens inasmuch as the light is being emitted at a wavelength that the human eye is less sensitive to.

A steradian is a unit of solid angle and as everyone knows, there are 4pi steradians in a sphere. For an isotropic light source (one that radiates equally in all directions, a physical impossibility if you consider the construction of the typical light bulb) a 1 candlepower blub would produce 1 cp x 4pi steradians = 1 lumen/steradian x 4pi steradians = 4pi lumens (about 12.6 +/- lumens) of radiant power. Using the ‘1 watt of radiant power at 555 nanometers = 683 lumens’ from above, our 1 cp bulb producing 4pi lumens = 12.6 lumens/683 lumens-per-watt = 0.0184 watts of radiant power.

In the case of a bulb producing “white” light (that is, light composed of all, more or less, frequencies - or wavelengths – of light) a 1 cp bulb would “equal” only about 0.014 watts, depending on the actual “whiteness” (sometimes referred to as the bulb's ‘temperature,’ frequently in degrees Kelvin) since – as stated above - the response of the average human eye is less for light produced at wavelengths other than 555 nanometers.

That ought to shine a little light on the "watts vs candlepower" question, although if you gave this explanation to the officer who pulled you over for having dim tail lights, you might find yourself in a '72-hour hold for observation' situation.

Scotty? Hello? Scotty, are you there…?

[pat in Santa Cruz]

Sponsored Links (Register now to hide all advertisements)

I have tried the two types of LED available for A tail lights. The more expensive one was the first on the market, it fits right in there behind your original lens and works well, nice and bright. The cheaper ones are a fully sealed unit that does not use the lens. It also works well and is also nice and bright. I am very happy with the light from both units. BUT, the cheaper ones do not fit the bezel without some filing or dremeling. (Why why why, cannot these aftermarket guys make parts that fit??) I used a repro bezel rather than file out an original, so one must take the cost of that into account as well and an hour's work fitting the unit. They are both sold by most A vendors.

[CarlG]

Originally Posted by pat in Santa Cruz

...The cheaper ones are a fully sealed unit that does not use the lens. It also works well and is also nice and bright. I am very happy with the light from both units. BUT, the cheaper ones do not fit the bezel without some filing or dremeling. (Why why why, cannot these aftermarket guys make parts that fit??) I used a repro bezel rather than file out an original...

Had the same experience. Found a couple of bezels on eBay for not much. Used them instead of my originals. (which probably aren't "originals" anyway.)

[jkeesey]

Originally Posted by pat in Santa Cruz

I have tried the two types of LED available for A tail lights. The more expensive one was the first on the market, it fits right in there behind your original lens and works well, nice and bright. The cheaper ones are a fully sealed unit that does not use the lens. It also works well and is also nice and bright. I am very happy with the light from both units. BUT, the cheaper ones do not fit the bezel without some filing or dremeling. (Why why why, cannot these aftermarket guys make parts that fit??) I used a repro bezel rather than file out an original, so one must take the cost of that into account as well and an hour's work fitting the unit. They are both sold by most A vendors.

I talked with the people from Snyders and they said they would not sell the cheaper version because it required modification to the original bezel. Apparently Brattons is okay with that.

[Dick Carne]

For safety purposes, I like the LED lights on the "teacup" rear lights, but I'm not aware of any kind of similar setup for the '28 drum tail light. Any thoughts on a similar alternative for these?

Thanks -

Dick

[Franchise_24]

Originally Posted by Dick Carne

For safety purposes, I like the LED lights on the "teacup" rear lights, but I'm not aware of any kind of similar setup for the '28 drum tail light. Any thoughts on a similar alternative for these?

Thanks -

Dick

I thought LED would be nice for my '28 (especially since I just have one tail light) but I'm running into the same thing... they all say will not fit in the drum tail light

[jkeesey]

http://www.ebay.com/itm/RED-24-LED-6...1c5041&vxp=mtr

theres a possibility these may fit

[Bill in Al]

My turn signals use the original stop lights and I'd like to know if the LED's will operate the flasher if I use them as replacements.

[jkeesey]

I believe there is a special flasher for LEDs but I could be wrong.

[Tom Wesenberg]

Originally Posted by Bill in Al

My turn signals use the original stop lights and I'd like to know if the LED's will operate the flasher if I use them as replacements.

Yes, and here is a thread about the good flasher:

https://www.fordbarn.com/forum/showth...+tom+wesenberg

[BILL WILLIAMSON]

While Ol' Bill wuz dickin' around with Vermin's tail lights, he found NO liscense plate lite lens on his L/H teacup thingy! I tole him sumbody used 2 R/H tail lites on this jitney! In the 'aforetime, Vermin had 1 drum (tuna can) lite, I KNOW, cuz I spotted them 3 "D" nuts in the sub frame!
Buster T.