Lumens vs candle pwr vs ??

[Wingman]

Hi All,

I'm thinking about upgrading to an LED flashlight (C or D cell) but am not sure how they compare brightness wise to the incand. I have an old Kel-Lite that throws a heck of a beam. I also have a 3 cell Mag Light with the focusing head that does ok, but not as good.

I see the ratings for lumens etc on the LED'S but that doesn't really mean anything to me as a comparison to what I have. If I was looking at a 3c LED Mag Light that was rated at something like 57 (working from memory, could be wrong about this number) lumens, can anyone compare how that would perform compared to either the Kel-Lite or Mag Light incand's I have. I'd be more interested in how they performed for distant rather than near lighting.

Thanks.

 

[js]

Wingman,

Welcome to CandlePowerForums!

You've come to the right place for answers to these questions . . . and you'll get some (or many) . . . but it's good form, good etiquette if you will, to try to find out if there are others who have asked the same questions as you, and to read the FAQ and sticky threads and do searches and all that.

OK. Short answer is that it is impossible to directly compare lumens to candlepower without knowing beam geometry and radiation pattern. Lumens is integrated intensity--ie. add up intensity over each little bit of area to get a total value. Mean Spherical Candlepower multiplied by 12.57 is lumens.

Now, the longer answer is that old maglites and other old incans aren't very bright for their size and weight. Todays high performance lights will be noticeably brighter.

There are a number of great flashlight review sites and you can find sticky threads with links to them in the reviews forum here--check them out. Plus, take the time to start looking through the last four or five dozen posts in the LED forum and this forum and you will almost certainly find a thread with a very similar question and lots of answers.

Take some time and look into things. It will be worth it. And in the future, be just a bit more conservative regarding posting a new thread to answer your question!

But, I don't mean to put you off by saying that! Welcome to CPF!

 

[Gunner12]

Candlepower can only be compared with lumen if it is spherical candlepower, as js said. Lumen is total output. A 10 lumen light can out throw a 1000 lumen one of the 10 lumen light throws a narrow beam and the 1000 lumen light has a very floody beam.

What you would want to compare is Lux which is measured at a distance, here the distance is usually 1 meter.

I'm not sure how many lux the Kel light.

How much would you like it to throw and at what price?

If you want to upgrade/mod your Maglite, check here.

:welcome:

 

[Wingman]

JS, thanks for the welcome and my apologies for not being more specific in my post. Being familiar with these types of forums, I should have known better, as the new guy, to post that I had read the stickies and had also done a search but didn't find the answer I was looking for. I did a search for "lumens" and got something like 492 hits. I honestly didn't read all of them.

To rephrase my question (and I'm not even sure there's an answer), if my Kel-Lite could easily lite an object 50 yards away, what kind of "lumen" rating would an LED light need to have to accomplish the same thing.

Gunner12, thanks for the link. Some great info there. I did read a lot about the Mag upgrades and the heat issue. It would appear that a light specifically made to use LED's is the way to go.

Again, thanks for the info and welcome.

Steve

 

[D-Dog]

:welcome:

Most of us on this forum prefer lumens over candlepower as most candlepower claims are bs (15 mil, 30 mil, etc), plus the total light being emitted from the light source is often a more useful measure of the "brightness" of a light.

Anyone who owns even a cheap laser point can say they have a "light" which will produce a heck of a lot of candlepower... but only a few lumens. One of the high efficiency fluorescent tubes is just the opposite, a really lot of total light output (lumens), yet very little candlepower, as the beam is dispersed.
If you are in the market for a light with a lot of candlepower (usually measured as lux at a meter), flashlights with large reflectors or flashlights with HID (high-intensity discharge) bulbs are your best bet. Aspheric lens also do great jobs. In fact, they can turn any mag into an awesome thrower J

There is really so so much to learn on this forum, and so many knowledgeable members here. Just remember to hold on to your wallet and enjoy the wild ride
-Derek

If you are looking for a fairly inexpensive (around here anyways) light with a nice build quality, a lifetime warranty, and great output for the size (over 150 lumens in 2aa form for example), check out Fenix lights at Fenix-store.com. I am not affiliated with them at all, however, I have had positive experiences with the number I have used.

 

[Gunner12]

50 yards isn't that far, something like this could work(it has less throw then the Mag3D), probably not as well as the kel light though. How well do you want it to be lit up?

What price range are you looking at?

 

[Wingman]

Gunner12, I've been lurking here for about a week doing various searches and reading up on all the different variables. I'd search/read till my head hurt then take a break. Your right. There is SO much info here and it will take awhile to work through it all.

The Kel-Lite was my light of choice for everything but mostly as an outdoor light. I just threw the 50 yard figure out there to illustrate my question. The Kel could throw for a much greater distance than that. As to how bright do I need, I don't need to light anything up like a fire scene but I'd like to be able to recognize what I'm lighting up as opposed to "there's something there".

I needed to go to Lowes today and had read about the Task Force light. They had a few 2c's (not the CREE but the package said 60x) there for $25 bucks so I picked one up. WOW. What a difference over the Mag. I went out on the deck and pointed the Mag at my shed in the back yard. The mag lit an area about the size of the sheds double doors. I hit the shed with the Task Force and it lit the WHOLE SHED. Plus it was way brighter than the mag (or the Kel). I wish it had a Mag type switch instead of the end cap switch but for my purposes and from what I read, I think this is a good replacement that will do what I need.

The one question I have regarding this light was asked in one of the Task Force threads but I never saw an answer. The question was does the TF light suffer (for lack of a better word) from reduced power/light the longer it stays on.

 

[Gunner12]

I'm not sure about that. If it still has the same driver as the Luxeon one, then check this review. 2.5 hours to 50% with alkaline C batteries. That one does decrease output over the semi regulated runtime(not as flat as a fully regulated light) but better then most direct drive lights.

All lights will loose output at sometime when the batteries can't support the light emitting device anymore, the main difference is how smoothly and quickly this drop happens(also depends on batteries).