Beam Characteristics

[EDcLED]

Here is one cryteria for specifying beam characteristics I would like to see manufacturers use.

A measurement of the hot spot diameter to distance expressed as a percentage. If shining a light on a flat surface a few feet away, say 10 feet produces a spot 7 inches (my measurement of a tighty focused M@g C or D, 7/120 = 5.8%) Spot diameter remains aproximately 5.8% of the distance to the target which means which means 5.8 feet @ 100 foot distance. My Fenix L0D cree hot spot runs over 4 times as broad at aproximately 25% spot diameter to distance which means the Fenix hot spot is covering over 16 times the area, would need 16 or more Fenix's, all else being equal, to cast tthe same light on the same 5.8 foot area. My lights range all the way from 5.8 percent for the M@g C ir D to 50% for a 28 LED 3 AAA which incidently I estimate to be 70 lumen.



Seems like manufacturers could include such a simple figure in their specifactions.

 

[jumpstat]

Welcome to CPF EDcLED,

 

[dyyys1]

Great idea! Even if manufacturers don't use it, it would be a useful number to put on websites like flashlightreviews.com. How would you have them factor in sidespill? The hotspot size is very important, but so is the size of the circle of softer light surrounding it. In fact, some light's don't have any well-defined barrier between the hotspot and the sidespill.

Welcome to CPF!

 

[EDcLED]

Thanks for the welcomes!

Adressing the side spill is a realy good question, maybe thats why we buy so many lights, to learn about it the hard way ;J How about this? A 1 foot diameter circle = 3.14 Square foot area -About 8 inches from target with LOD-CE and 5 inches from target with M@g 2C 3W LED each produced a 1 Ft dia spill.

The more criteria added the more fun it gets but a ratio of intensity between spot and spill would probably be helpfull. Only where substantial definition exists would there be any need for numbers and a lack of would assume an entirely smooth beam. like my 28 LED "wall of light"

I found it interesting that the L0D spill was about equally intense and smaller dia by a 1.6 factor

L0D-CE primary spot 1 foot Dia @ ~ 8 Ft
L0D-CE spill area 1 foot Dia @ ~ 8 In

M@g primary spot 1 foot Dia @ ~ 33 Ft
M@g spill area 1 foot @ ~ 5 In

I realy have spent many hours reading candle power forums, it's GREAT!

Thought I would post a few of my thoughts
Thanks to all.

 

[dyyys1]

The easiest way to show the beam characteristics would be to show a picture of the beam on a target with some sort of scale on it at a set distance (such as one meter). You can find these on online review sites, but it would be nice if they were on the boxes in the store.

 

[EDcLED]

A pic of the beam on a target seems like a good way and I have spent much time looking at Doug P's however at one meter the M@g spill is over 7 feet across the LOD is less than 4 feet.

 

[FILIPPO]

Spot diameter remains aproximately 5.8% of the distance to the target which means which means 5.8 feet @ 100 foot distance.

:huh2: ..........

welcome in CPF and good idea!!:twothumbs

 

[EDcLED]

A pic of the beam on a target seems like a good way and I have spent much time looking at Doug P's however at one meter the M@g spill is over 7 feet across the LOD is less than 4 feet.

 

[EDcLED]

Uh huh

 

[Owen]

Interesting idea. I like it.
Even more, I'd like a % comparison of the hotspot vs. spill brightness. One of the things I notice about some of my lights with more concentrated spots is that even if you compare the spill to another light that isn't as bright, but has equal spill...in actual use, your eye will adjust to the brighter spot, and sometimes render the spill useless.
Case in point: I've got a Z3 that I use a Wolf Eyes 9V D26 LA in. Wide spot that fades into the spill. In use, it is very much a "flood", lighting up a wide area. On the other hand, the M3 with MN11 HOLA has spill that is just as bright when you compare them side by side on a wall, for instance. But it's hotspot looks three times as bright. When you use it in the real world, you don't even notice that it has any spill, just a large, bright spot. Great when there's a little distance involved, not great at close range. It makes a huge difference in use sometimes, which is the same reason I've chosen that 9V D26 over other lamps that had greater output like some of the Lumens Factory offerings, and some that have "better" beam quality in the form of a brighter and rounder spot with more sharply delineated spot/spill, like G&P/Digilight.
I notice the same thing with LEDs, particulary comparing a 5w to an overdriven 3w that may have spill that is just as bright, but also a correspondingly brighter spot that seems to negate the spill's brightness in actual use, causing the 5w to more effectively light up a wider area at close range even though it technically isn't "brighter".

I know that hoping for a manufacturer to provide this kind of info is some serious wishful thinking, but while we're dreaming...

 

[EDcLED]

Anyone catch my mistake in the 1 foot diameter circle being 3.14 square foot? Me believes 1 foot radius or 2 foot diameter makes 3.14 square feet. Consequently I moved my L0D-CE away from the target to make the spill beam 2' across, distance was 17" but the M@g 2C 3W LED had to be closer at 12" for the same 2' spill.

 

[EDcLED]

Some aproximate examples of distance from target to produce 2 foot diameter hot spot (3.14 sq ft)

28 5mm LED 4'
Fenix L0D-ce 8'
ARC-P 10'
Nuwai 303 10'
Fenix LxP 12'
Mini Mag LED 17'
D mag LED 33'
D mag incan 40'

 

[EDcLED]

Great idea! it would be a useful number to put on websites like flashlightreviews.com.

Or CPF. Would like to know about other models some of you have. I am thinking this thread might have been more appropriate in LED

 

[EDcLED]

in the real world, you don't even notice that it has any spill,

I had to take special notice of the spill on my stock 2C Mag LED.

First thing this morning, before turning on any electric lights, I grabbed the light, opend the front door, pointed the light in the sky. I found by using only the outside edge of the spill beam I can easily see the electric utility pole which is across the road diagonally aproximately 40 yards. While not real world use it does say something about the spill, consider also that the spill at 1 meter is very, very wide, nearly 2 meters. Should be wide enough for the most demanding, if not bright enough, LOL

 

[Owen]

I guess the whole "spill in contrast to the spot" thing, completely escaped you.

 

[EDcLED]

I guess the whole "spill in contrast to the spot" thing, completely escaped you.

At the speed of light? I don't want to think about that LOL. Seems like you were describing a light with spill vs spot intensity in the 33% vacinity, compared to those below. I think if 2 foot diameter was used as a standard buying would be eisier.

My aproximate measurements of MagLED"

Spot 2' dia @ 30ft

Spill 2' dia @ 12in

Spill vs Spot intnsity 1% +/-?

Aproximate measure of SL TL-2

Spot 2' dia @10ft

Spill 2' dia @ 20in

Spill vs spot intnsity 1% +/- ?



Some where I have seen graphs with Vertical representing intensity and Horizontal representing dgrees from axis. I cant remember what web site.

 

[EDcLED]

Beam characteristic that makes one beam, over 500 lumens, hot spot about 8 feet in diameter at 30 feet with a gradual spill transition to about 25 foot in diameter. I have just aboiut concluded for now I should go with the AA L1D-CE.

 

[Art Vandelay]

How about a meter? Lux and lumens are used more often at CPF than foot candles.

At the speed of light? I don't want to think about that LOL. Seems like you were describing a light with spill vs spot intensity in the 33% vacinity, compared to those below. I think if 2 foot diameter was used as a standard buying would be eisier.

My aproximate measurements of MagLED"

Spot 2' dia @ 30ft

Spill 2' dia @ 12in

Spill vs Spot intnsity 1% +/-?

Aproximate measure of SL TL-2

Spot 2' dia @10ft

Spill 2' dia @ 20in

Spill vs spot intnsity 1% +/- ?



Some where I have seen graphs with Vertical representing intensity and Horizontal representing dgrees from axis. I cant remember what web site.

 

[EDcLED]

Art, You mean beam characteristics at one meter? I like Doug p's way 1 lux @ x # of feet for throw, doesn't tell the beam diameter though, Well about meters Id probably buy as many of those as I do everthing else, where does it end?

 

[Art Vandelay]

Art, You mean beam characteristics at one meter? I like Doug p's way 1 lux @ x # of feet for throw, doesn't tell the beam diameter though, Well about meters Id probably buy as many of those as I do everthing else, where does it end?

No, I meant the size of the hotspot.