What is a lumen? Candlepower? A Footcandle? A Lux?

[whisler151]

Maybe its the terminology, but I I don't think that's true. Think of it this way: technically speaking lumens are measurements taken at what you're lighting up. Candlepower is a measurement taken at the surface of the bulb.

Are you getting your info form Wikipedia?

Edit: Yes, I agree with you. That is basically the same thing that I am saying. The two are different measurments of light.

 

[BigJ]

Are you getting your info form Wikipedia?

LOL of course! Wiki knows all!!



(Nope, I've been down this road on other auto platforms before. Its what I think I've come to learn by dozens of similar discussions over the years. Don't mean I'm right though.)

 

[whisler151]

The point i'm trying to get across is that these are two different measurements and you cannot accurately convert candlepower to lumens.

 

[swoop1156]

So like gasoline and diesel. Same effective purpose to fuel a vehicle, but they are completely different.

BAM *******! There's some realism for your asses!

 

[BigJ]

The point i'm trying to get across is that these are two different measurements and you cannot accurately convert candlepower to lumens.

I hear ya. My only question on that then might be this: why then is a lumen calculated with candlepower as a factor? The math seems to say they are related.

Definitely an academic question though. I see what you're saying when it comes to effectiveness in the dirt.

 

[whisler151]

I hear ya. My only question on that then might be this: why then is a lumen calculated with candlepower as a factor? The math seems to say they are related.

Definitely an academic question though. I see what you're saying when it comes to effectiveness in the dirt.

They are definitely related, just not directly comparable. The math that is suggested would say my lights equal 13.8 mil lumens...obviously not accurate.

 

[BigJ]

Huh. I think you are on the right track with your math, just off in your decimal places? An easy thing to do because when saying "candela" you're really saying millicandelas.

Try this

candela (millicandela) to lumen conversion wizard

or this

http://www.ledrise.com/shop_content.php?coID=17

For the purposes of our discussion, you can let 1 candlepower = 1 candela. If I plug in your lights, and assume they were measured at the best possible angle of 360deg, I get a total of 13800 lumens. That's a much more reasonable number, no?

 

[whisler151]

For the purposes of our discussion, you can let 1 candlepower = 1 candela. If I plug in your lights, and assume they were measured at the best possible angle of 360deg, I get a total of 13800 lumens. That's a much more reasonable number, no?

And to add to the confusion of converting candlepower to lumens, KC lights says that thier HID 8" lights produce 814,000 candlepower which they say is equal to 5,000 lumens.

While you may be able to work math out to convert the light, it is not practical as the two measure light differently. One is the brightness of the source of the light and the other is the brightness of the light as it hits a surface area. Way too many variables.

HID: Lights « Hid « 8 Hid Long Range Black « KC HiLiTES: Auxiliary Lighting, Off Road Lights, HID Off Road Lights, Fog Lights, LED Light Bars, Driving Lights, Light Bars, Wiring Accessories, Flashlights, Torches

Halogen: Lights « Rally800 « Rally 800 130w Long Range Black « KC HiLiTES: Auxiliary Lighting, Off Road Lights, HID Off Road Lights, Fog Lights, LED Light Bars, Driving Lights, Light Bars, Wiring Accessories, Flashlights, Torches

And i'm out...

 

[BigJ]

And to add to the confusion of converting candlepower to lumens, KC lights says that thier HID 8" lights produce 814,000 candlepower which they say is equal to 5,000 lumens.

That makes perfect sense. Using the math we can figure they measured (or most likely calculated) at 180degrees... which is basically the entire face of their light, right? I think that helps exactly prove what's going on here, and how KC in particular chooses to advertise their lights (fairly, in my opinion since 180 degrees is a real number, where as for example 360 degrees wouldn't be since there's no light coming out of the back, blowing up your grill etc).

While you may be able to work math out to convert the light, it is not practical as the two measure light differently. One is the brightness of the source of the light and the other is the brightness of the light as it hits a surface area. Way too many variables.

Yepyep!

And i'm out...

Hey its all good whisler. We are saying the same exact thing, backed up by the math now. We're just going about the phrasing and concepts in different ways. But either way, we're on the same page.

 

[whisler151]

That makes perfect sense. Using the math we can figure they measured (or most likely calculated) at 180degrees... which is basically the entire face of their light, right? I think that helps exactly prove what's going on here, and how KC in particular chooses to advertise their lights (fairly, in my opinion since 180 degrees is a real number, where as for example 360 degrees wouldn't be since there's no light coming out of the back, blowing up your grill etc).

Yepyep!

Hey its all good whisler. We are saying the same exact thing, backed up by the math now. We're just going about the phrasing and concepts in different ways. But either way, we're on the same page.

Yep, it's all good.