Flash light Jargonese.

[Mike, Lord of the Spammers!]

As you probably all know I've just started to really get into flashlights

The thing is you go on places like CPF, and they all use flashlight specific jargon, and my not coming from an electronics background, it's all a tad confusing

So I'm sure I'm not the only relative newb when it comes to this, so I thought it might be a good idea to do a list of the more popular anagrams, technical features, terminology and other jargon to help us pep's out

Over to you learned ones

[Benner]

Button - thing that turns it on
Battery - thing that powers it

 

[NutSAK]

I'll try to put a list together for you after work.  Are there any terms you are confused about right now to get the list started?

There are several folks here besides myself who are long-time cpf members who can certainly help you with this.  Prime comes to mind, and I know WH and John (Titan) are members over there too.  I'm sure there are several more that I'm forgetting...

Once we get a list together, I think it would be a good candidate for a sticky.

[zepla]

I'm all set flashlight wise (for now) but a list like that sure would helped me out at the time. I went to CPF at the time and there is some serious tech talk going on over there 

[GraysonK]

Button - thing that turns it on
Battery - thing that powers it

 

 

[Mike, Lord of the Spammers!]

Once we get a list together, I think it would be a good candidate for a sticky.

That's my thinking too

Nothing specific atm, but a breakdown of the most commonly used acronyms and jargon would be very useful mate

[nuphoria]

Something that confiuses me is lux v lumens... don't understand the relationship between the two. 

[Gareth]

Something that confiuses me is lux v lumens... don't understand the relationship between the two. 

I think I have a handle on this but a proper Jamie could come along and correct me.  As I understand it Lumen is a measure of the total amount of light put out, lux is how bright it is at a certain spot.  I think of it as something like alcohol ( ) so lumens are like the amount (i.e. a pint or a shot) and the lux is the % alcohol (beer or whisky).  I'm not sure that analogy quite works, but it makes sense to me. 

[ringzero]

Something that confiuses me is lux v lumens... don't understand the relationship between the two. 

Here's an explanation I wrote for MickyD in another thread:

Quote from: Mike, Lord of the Spammers! on October 03, 2009, 05:27:44 PM
So instead of lumens, what should us Jamie newb's be looking for when assessing performance 

LUMEN output is useful because it is a measure of the total light pumped out by the torch.

LUX measurement is useful because it is the intensity of the brightest part of the torch's beam.  LUX measurement can be used to predict how far the torch will throw a useful beam.

Example:

20 Lumens is approximately the output of a cheap, plastic 2D supermarket incandescent torch with fresh cells.

Such a torch might produce 900 Lux in the center of its beam.

Take the square root of 900 to get 30.

This is the distance in meters at which the torch will put 1 Lumen of light on a 1 meter sqaure target.

If your eyes were totally dark adapted and you were in a dark wildnerness scenario, then that 1 Lumen per meter squared might be a useful amount of light.

In an urban scenario (streetlights, porchlights, etc.) that 1 Lumen/m2 would probably be useless to see anything.

Derate that 30 meter distance by half to 15 meters.  This is the aprroximate distance at which a 20 Lumen, 900 Lux torch would usefully illluminate a target in an urban scenario.

In other words, for use around town, a 2D incan supermarket torch is predicted by its Lux measurement to be useful out to about 50 feet.  Out in the dark woods, the same light might be useful out to about 100 feet.

Both of these numbers seem to fit well with the experiential reality of using such a torch, so the mathematical model is fairly good.

Summary:

Take the square root of the Lux measurment, which gives the useful throw in meters for a wilderness scenario.

Divide that by two for an urban scenario, which gives the useful throw in meters for urban use.

If you wish, multiply the throw in meters by three to get throw in feet.

.

[nuphoria]

Thank you.... I will come back to that when I've eaten something and see it makes more sense 

[NutSAK]

LUMEN output is useful because it is a measure of the total light pumped out by the torch.

LUX measurement is useful because it is the intensity of the brightest part of the torch's beam.  LUX measurement can be used to predict how far the torch will throw a useful beam.

Yep, that's pretty much it.  Another way to put it:

"The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. A flux of 1,000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1,000 lux."

Lux and footcandle measure the same thing, but footcandle is basically lumens/sq. ft. and lux is lumens/sq metre.

LUMEN output is useful because it is a measure of the total light pumped out by the torch.

Not always--in fact, in the case of most flashlight manufacturers, they specify the lumen output of the emitter (LED) itself rather than the lumen output of the torch.  There will always be a lumen loss due to the inefficiencies of the reflector and lens (window).  Therefore, it makes it difficult to compare the lumen specs from one manufacturer to another.  Measuring true torch lumens requires an integrating sphere, which is an expensive piece of equipment, so many times the manufacturer simply states the lumens spec of the emitter at whatever current it is being driven.  Typically only the high-end manufacturers such as Surefire state torch lumens or "lumens out the front" (OTF).

[GraysonK]

Something that confiuses me is lux v lumens... don't understand the relationship between the two. 

I don't know anything about this but this article kind of cleared it up for me a little

http://www.brillianz.co.uk/data/documents/Lumen.pdf

[NutSAK]

That's a good article.  Wikipedia also has some good info about flux (lumens) and lux.

[John]

Mike I could put together a list but specifically what are you confused about?    

 to start and not to be too technical  


Lumen= usually a measure of light output

Lux....= measure of light intensity

Regulator =  a circuit that takes energy from a battery and converts it to a (usually) constant current or voltage to feed the flashlight's LED,normally the output will stay constant throughout the life of the battery but will drop off significantly when the battery can no longer supply the required energy.

DD= direct drive Non-regulated light output usually in these flashlights the light will start at maximum ouput and diminishes slowly throughout the life of the battery.

Forward clicky tailcap switch= A switch that has a momentary on before a further push latches on for constant on.

Reverse clicky switch= simply put normally there's no momentary on it's just click for on and click again for off.

UI= user interface

SMO reflector= basically a smooth mirror finish mainly used for throw

LOP= light orange peel, in texture give good balance of both throw and spill apparently.

OP= normally the heavier orange peel texture used for ironing out cree rings and usually gives good side spill of light.

LE(light engine) or pill= usually meaning the circuit and LED are housed in a brass/copper slug/can and can be screwed either into the reflector/head itself or screwed into the battery pack/housing,mostly tho they will screw into the head.

[NutSAK]

That's a start! 

[prime77]

Some jargon that comes to mind right away for me.

User Interface- The way you turn the light on and off. On multimode lights the UI can be very important. It's no good having tons of levels if it's a pain to switch between them.

Foward Clicky- A click on UI where the light can be activated by slightly pressing the button but not clicking it all the way. Forward clickies allow for momentary activation. Tactical lights generally have a forward clicky.

Reverse Clicky- A click on UI where the light is activated by pressing the button and clicking it on. Reverse clickies do not allow for momentary activation.

Reflector- Used to reflect the light froward. There are different types textured reflectors commonly smooth and orange peel or OP. Smooth ones will give you more throw but with a more ringy beam. OP will take some of the throw away but give you a smoother cleaner beam.  

Optic- Some lights don't use reflectors to project the beam forward but use shaped glass or plastic. Optics can be used to focus the beam for more throw or spread the beam out for more flood. Surefire uses a optic they call TIR or Total Internal Reflection on allot of there e-series lights for throw. Here is a pic of one outside of the light.


Throw- Used to describe how far the beam of the light protects. Some lights are very throw orientated.  An example of a throwy beam a Surefire E2DL:



Flood- Used to describe how much surrounding area the beam covers. The first generation Surefire L4 is very well known for having a floody beam:


Diffuser- A device that can be put on the light to diffuse of change the pattern of the beam. An example would be the Surefire F04.

[Mike, Lord of the Spammers!]

Superb work John and James

[prime77]

Damn John beat me while I was typing. Oh well. What he said too.

[NutSAK]

Good stuff fellas! 

[John]

Hi guys here's a great resource on everything about batteries should you ever have a qeustion 
http://www.batteryuniversity.com/index.htm

[Mike, Lord of the Spammers!]

Hi guys here's a great resource on everything about batteries should you ever have a qeustion 
http://www.batteryuniversity.com/index.htm

Thanks for the link