The Firing Line Forums

Go Back   The Firing Line Forums > Hogan's Alley > Tactics and Training

Reply
 
Thread Tools Search this Thread
Old January 26, 2013, 09:14 AM   #1
Verbal Clint
Member
 
Join Date: March 13, 2012
Location: Lubbock, TX
Posts: 69
Candela vs Lumen

Just wondering which you guys consider more for a tactical light: candela or lumens. The reason I ask is this...there are VERY FEW situations I can think of where I would need a very wide field of view with a flashlight. I typically don't make it a point to find myself out of my car in a place that is so poorly-lit that I need a tac-light. However, if I'm at my house where the biggest FOV is one end of the living room to the other, I can really see myself needing some light power. Thoughts?
__________________
Luke 11:21
"When a strong man, fully armed, guards his own palace, his goods are safe."
Verbal Clint is offline  
Old January 26, 2013, 09:29 AM   #2
Alabama Shooter
Senior Member
 
Join Date: December 20, 2012
Location: Sweet Home
Posts: 886
It depends. I have a very large room in my house that has a lot of furniture. I like having a very wide field of light in that room instead of a bright directional light. For the rest of the house I prefer more of a directional bright light.

During clearing operations I used a helmet mounted light for looking around and a issue Surefire on the rifle. The SF while heavy, threw out a huge near sun like directional beam while the head light allowed me to do a number of other things without lowering my weapon or using another hand. The arrangement worked very well and I have essentially adopted it for home use.

So for HD my suggestion would be both. A weapon mounted light with a high intensity directional beam and wider head lamp beam.

For SD I don't carry a weapon mounted flashlight, just my regular flashlight on the belt. For my plans this is adequate.
__________________
Tomorrow is the most important thing in life. Comes into us at midnight very clean. It's perfect when it arrives and it puts itself in our hands. It hopes we've learned something from yesterday.
Alabama Shooter is offline  
Old January 26, 2013, 11:28 AM   #3
Verbal Clint
Member
 
Join Date: March 13, 2012
Location: Lubbock, TX
Posts: 69
Only having one in my weak hand for SD, I'm just wondering what the more important measure would be.
__________________
Luke 11:21
"When a strong man, fully armed, guards his own palace, his goods are safe."
Verbal Clint is offline  
Old January 26, 2013, 03:28 PM   #4
JohnKSa
Staff
 
Join Date: February 12, 2001
Location: DFW Area
Posts: 24,928
Candela and lumens are just two different ways of measuring light output.

As I understand it, Candela is based on the level of highest light intensity in the beam while lumens actually measures the entire light output of the device.

Neither measurement tells you a lot about whether you will get a tight beam or a diffuse beam, that has more to do with the design of the light.

All else being equal, a large smooth reflector has the potential to provide a tighter beam while a small reflector, or a reflector that is textured will tend to provide a more diffuse beam.

Inside a house, where walls and ceilings are typically light colors, you get a lot of scatter. You can often illuminate an entire room surprisingly well by shining the light at the ceiling in the middle of the room.
__________________
Do you know about the TEXAS State Rifle Association?
JohnKSa is offline  
Old January 26, 2013, 04:32 PM   #5
TXAZ
Senior Member
 
Join Date: September 5, 2010
Location: McMurdo Sound Texas
Posts: 4,322
+1 JKSA

As an example, assume you have a 5mW laser and a 1W LED light on your pistol. The laser has all of its photons in a super small column that does not spread out much from you pistol out to 100 yards. The LED light has a much lower intensity than the laser but gives off 200 times more photons. Since the light spreads out rapidly, you can't see squat at 100 yards with it.

The laser has a massive intensity ie.; high candella value but very few lumens. You can illuminate a super small area (say 1/4" diameter) at a very long distance, but can't see squat 2" away from the laser dot.

Conversely, the light has substantial lumens but lower candella. You can see most everything in a decent sized room but not much further out.

So to your question, If you want to aim, quickly target, or blind the opposition (permantly or temp) it's pure intensity (candella) delivered on-target. If you want to be able to see a wide area quickly then it's lumens.

Does that help any?
__________________

Cave illos in guns et backhoes

Last edited by TXAZ; January 26, 2013 at 04:49 PM.
TXAZ is offline  
Old January 26, 2013, 10:23 PM   #6
Alabama Shooter
Senior Member
 
Join Date: December 20, 2012
Location: Sweet Home
Posts: 886
Quote:
Inside a house, where walls and ceilings are typically light colors, you get a lot of scatter. You can often illuminate an entire room surprisingly well by shining the light at the ceiling in the middle of the room.
In a house with light walls you can actually get pretty good effects with a green laser too. Just not in my house.
__________________
Tomorrow is the most important thing in life. Comes into us at midnight very clean. It's perfect when it arrives and it puts itself in our hands. It hopes we've learned something from yesterday.
Alabama Shooter is offline  
Old January 26, 2013, 10:30 PM   #7
shootniron
Senior Member
 
Join Date: April 16, 2011
Location: Georgia
Posts: 1,599
Also, ad to this equation, that the tac light is often used more for other uses than it is tactically...so you may want a light that serves the other purposes well, too.

To answer your question, lumens rule the day for me now as this is the primary descriptor assigned to most lights now and it is easy to understand and see the difference for me as I am mostly uninformed as to what most of the specs on flashlight mean.

Last edited by shootniron; January 27, 2013 at 12:52 AM.
shootniron is offline  
Old January 27, 2013, 12:51 AM   #8
Scubasimmons
Senior Member
 
Join Date: February 10, 2009
Location: Sammamish, WA
Posts: 119
Lumens is a much better measure of light output.
Scubasimmons is offline  
Old January 27, 2013, 10:56 PM   #9
OcelotZ3
Senior Member
 
Join Date: March 20, 2008
Posts: 229
Yeah... Who is using Candelas these days anyway?

I used to see LEDs spec'ed with those, but not so much anymore.
OcelotZ3 is offline  
Old January 29, 2013, 11:30 AM   #10
mikikanazawa
Senior Member
 
Join Date: September 26, 2004
Posts: 449
It doesn't really matter because the light manufacturers don't use the same method of measuring output whether it be candelas or lumens.

For example, most of the LED-based flashlights that use the same LED will have different output ratings. Some just use the lumen output spec provided on the LED manufacturer's spec sheet. And some will take into account optical losses (from the reflector, lens, window, etc.) and electrical losses (diminishing battery power). So it is possible to have a flashlight with a 100 lumen rating and another flashlight with a 500 lumen rating, and still have greater visible output from the 100 lumen flashlight.

The eye isn't equally sensitive to light at all wavelengths, so it is possible to have a flashlight with an extremely high lumen rating yet still difficult to see with. In a case like that, the output may be biased to to IR or UV portion of the spectrum, or it may be extremely narrowband, with a white appearance, but most of the emission in the blue or green area of the spectrum.

Sunlight appears white to us because the sun has a very broad (high bandwidth) spectral output. LEDs appear power efficient because their spectral output is more selective with lower average bandwidth.

So to answer the question -- just get a flashlight you'd enjoy owning!
mikikanazawa is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:21 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.08150 seconds with 10 queries