Ideal flashlight + comparison with 100 watt bulb

My reason for posting is two-fold.

First off, I'd like a flashlight that fills these requirements:
* Pure white (not orange/yellow if possible)
* At least 120 spherical degree dispersal angle
* Preferably lighter than 10 pounds
* At least 10 million candlepower

Any ideas? What's the best currently out there?

The second reason is because of some confusion to do with candlepower and light bulbs. I hear that a 100 watt bulb emits an equivalent of 120 candela. I also hear that candlepower is basically candela (more or less).

So that means these 10 million candlepower torches are the equivalent of 80,000 100-watt light bulbs! This I can't accept. What gives?

I would still be grateful for some answers to this post if at all possible.

Well, I think there is no reaction because you are asking the impossible !!



But first let me welcome you to these forums...

Ok.. Candlepower: lesson 1: There are two different kinds of candlepower.
The candlepower type you spoke of when you mentioned the 100watt bulb is called MSCP (Mean Spherical CandlePower) It's the amount of candlepower you measure everywhere around the lamp.

The 10million candlepower claimed on boxes of various spotlights is called Beam candlepower! That is the amount of candlepower measured in the brightest part of the beam.

You can immidiately forget these claims: They are highly exaggerated ! They are just to get one's attention (and mostly it works..)

In earlier times manufacturers were more honest about their claims, but it got out of hand: If one claimed 2 million cp, the other claimed 3.5 million cp !! The highest claim a saw for a torch a while ago was 30 million, but I think I don't have to wait long for someone that makes an even more stupid claim...

Today only a few manufacturers are honest about the cp-output of their torches..

The closer you concentrate the light of a lamp to a tight beam, with the use of a reflector, the higher the beam candlepower output will be. But it is limited by the diameter of the reflector and the surface brightness of the lamp! With a 5 inch reflector and a quality halogen bulb you can reach 200,000 beam candlepower at the most !! Put a HID bulb in the same reflector and you will measure about 800,000 cp.. Put a Xenon short arc in the same reflector (Maxabeam) and you will measure about 6,000,000 cp!!

And to confuse you a little more: With all the examples mentioned above the lamps used have the same light output in lumens (=the total amount of light they produce)!!

So the beam candlepower output of a torch doesn't say anything about the lumens output: You can have a low lumens output light with high beam candlepower output and the other way around.

So all I can say is : FORGET THE IDEAL FLASHLIGHT !!! And start to make compromises: Here on CPF you can find many powerfull solutions and mod's..
Start to explore CPF and find the torch that is best suited for your needs.


Regards,

Ra.

Ra's explanation is very good. If you have any trouble understanding anything the best way i have found is to read as many posts as possible and you will gradually pick up an understanding of what is possible and what is available.

Thanks for the welcome!

Well, I think there is no reaction because you are asking the impossible !!

Click to expand...

Well if I could at least have the nearest flashlight that fits this description, then I'll make do.


Okay, about the tech stuff, well, I'm somewhat surprised to say the least! There's so much misinformation out there (and it pains me to add, even on my own site to do with lumens/candela, which I have immediately taken down, though in my defence, I think I explain it clearer than maybe any other site apart from the obvious mix up with unit types), that I have been confused over the whole thing.

You have certainly explained it clearer than most, and I particularly like the way you said all of those different angles, can still produce the same lumens or total output (some people will want long range illumination (think lazer style), and others will want short range; think light bulb). I knew all of this before, except I confused lumen with candela!

Can you do me a favour? There are four variables to take into account when measuring light:
Light source Intensity
Light source size
Light source distance from object
Size of object area

We have four units:
Candela
Lumen
Nits
Lux

So we can assign what needs to be taken into account whenever we're asked to measure one of these units.

You need to know the light source's intensity before you can find out the nits.
You need to know the light source's intensity and size before you can find out the lumen (or MSCP in fact).
You need to know the light source's intensity and size, and also the object/observer's distance from the light source, before you can find out the lux.
You need to know the light source intensity and size, and also the object/observer's distance from the light source, and the observer's size before you can find out the candela.

Is this correct? If it is any way ambiguous, please say, as I want to create a fully non-ambiguous way of teaching this stuff, and I admit there could be other ways of interpreting what I have said, despite the fact that I can't see any other ways.

A lazer is very intense, however it won't light up a room. So its total output (lumens) is very low. So would we say its nits level is very high (light source intensity variable only) ?

The two measurements that are most important to me are lux (like beam candlepower, lux measures the brightest part of the beam, which is a good indicator of throw) and lumens, which is the total amount of light.

Wanting 10 million candlepower in a 120 degree beam is difficult, presuming you want the 120-degree beam to be relatively uniform in brightness, i.e, not a tight hotspot with faint spill.

You didn't mention runtime, which is a key factor, or what you want to do with the light, which would help people give you advice. But, here are some ideas:

X990 -- a HID, rather large by Mag 3D standards, but within your limits, that puts out about 3,000 lumens. (Mag 3D is about 35 lumens.) Runtime about an hour.

Mag85 -- a regular Mag, usually 3D or so in size, that puts out 800 to 1,000 lumens depending on the quality of construction and types of parts you use. Runtime depends on batteries, but typically 30 to 40 minutes. You can make it a thrower (lots of lux) with a smooth reflector or a wall-of-light flood with a heavy stipple reflector.

Mag100 -- like the above, with a lot more light and less runtime.

HID Power Light -- a smaller HID than the X990, but with lots of runtime (90 minutes, I think) and well over 1,000 lumens. Tends to be very white. Beam is narrow.

I'd suggest that you start with a high-quality Mag85 with a HS reflector and high-current battery pack. You'd get a dazzling, wide and yellow/white flood. You can build one or buy one for $200 or less and it will give you a good frame of reference.

Candlepower is not too helpful, as it's just the magnitude of brightness at the point of the beam's maximum intensity. You can achieve 10 Mio if you have a highly focused beam (as seen in some spotlights you can buy), however it can't be achieved (at least now) with a portable flashlight that has a 120 degree angle.

So your 120 degree requirement won't work with your 10 Mio Candlepower requirement.

mobile1,

Yeah it truly seems that these manufacturers should measure in lumen, not candela (as like you and Ra effectively say, candela depends on the observer's distance and size from the light, as well as the bulb's actual output, so it's easy for them to 'cook' the measurements).

Angle is still important of course, but this should be given separately. The point is, candela can be 'cooked', but at least with Lumen, you know what you're getting.

Honestly, it would be great to have objective measurements on things like flashlights. Trading standards and independent societies should see to it

Josey,
Those look interesting thanks. Although I would have expected more of a big 'carry' type flashlight, than the relatively small torches you suggested, to give off massive light output. Something like this
http://www.gadgetizer.com/images/15millioncandlepowerflashlight.jpg

I'd like the time to last around an hour, possibly 2 even, and have two different modes, so that one powerup of the battery can laster longer, on a weaker light.