Someone to test lumens of my flashlight.

[Orion]

I'm wondering if there is someone who would be willing to test the lumens/output of a flashlight of mine. It's a QIII that I put a Cree Q4 in and would like to know what it's output is now.

If you have a lumens tester, I would like to know if you would be willing to check this out for me. I would include an amount necessary for return shipping back to me.

I will only send it to someone who has been on this board a long time and is well known and reputible. If that's you, let me know if you'd be willing to help me on this test.

Thanks!!

 

[Bullzeyebill]

I don't have a lumen tester, but you can, if you buy an inexpensive lightmeter, do your own lumen testing. Accuracy will not be near the expensive setups, but it will allow you to compare your own lights to each other, and compare upgrades.

I use simple bounce with lightmeter in an room that is more or less consistent. A bathroom without windows, or a bathroom at night. Set up lightmeter in same spot and flashlight about two feet away, or so, and record lux numbers bouncing light off the ceiling. I have done this for several years now and find results very consistent. To establish a base line I might check a light with a more or less know output, for example a newer KL5, which puts out approximately 100 lumens, then I will best the light of my choice. This gives me an estimate up and down about the output of different lights.

Some may po-po this approach, but it does give some information and is much better than subjective testing


Instead of buying your next light, buy an inexpensive lightmeter.

I know that this does not satisfy your present need, but just a suggestion.

Bill

 

[yellow]

You could also check the current that goes in the led and thus make some kind of guess how bright the light should be.

f.e.: most Fenixes or whatever lights else: NO 1 A @ led --> no way, and thus no surprise, that there is no 200 lumes out the front

 

[Nake]

I don't have a lumen tester, but you can, if you buy an inexpensive lightmeter, do your own lumen testing. Accuracy will not be near the expensive setups, but it will allow you to compare your own lights to each other, and compare upgrades.

I use simple bounce with lightmeter in an room that is more or less consistent. A bathroom without windows, or a bathroom at night. Set up lightmeter in same spot and flashlight about two feet away, or so, and record lux numbers bouncing light off the ceiling. I have done this for several years now and find results very consistent. To establish a base line I might check a light with a more or less know output, for example a newer KL5, which puts out approximately 100 lumens, then I will best the light of my choice. This gives me an estimate up and down about the output of different lights.

Some may po-po this approach, but it does give some information and is much better than subjective testing


Instead of buying your next light, buy an inexpensive lightmeter.

I know that this does not satisfy your present need, but just a suggestion.

Bill

I did it this way myself for awhile, then went to using a converted milk carton for a lightbox, like Quickbeam.

 

[Bullzeyebill]

Nake, did you notice a difference with lightbox? How much, roughly.

Bill

 

[Orion]

Could someone extrapolate a rough figure of what it could be given the following inputs:

Q4 Cree
Whatever current standard QIII's ran at
The QIII's textured reflector

Is it possible to assume a ballpark figure with this information?

 

[Windscale]

I did it this way myself for awhile, then went to using a converted milk carton for a lightbox, like Quickbeam.

I use a light meter as well. You don't need the most expensive ones. But you do need a reasonably professional one. And it should be able to measure incident light. Mine is a Sekonic.

For UK members, a thread is in existence in The Cafe for your benefits. Please take a look.

 

[Nake]

Nake, did you notice a difference with lightbox? How much, roughly.

Bill

Well, the lux numbers are much higher than with a ceiling bounce. I tested a few stock lights and the numbers were very close to what Quickbeam got for the same lights. Since the approximate lumen figures that Quickbeam got are also very close to what Chevrofreak gets I consider it a good approximation for my modded lights.
Quickbeam also had his numbers checked against an integrating sphere and found them to be close to what it showed.

 

[Nake]

Could someone extrapolate a rough figure of what it could be given the following inputs:

Q4 Cree
Whatever current standard QIII's ran at
The QIII's textured reflector

Is it possible to assume a ballpark figure with this information?

I have a QIII with a Cree Q4 and it shows about 120lm. It has a FLuPIC and on burst shows a little over 1A at the tailcap. If I remember correctly the stock driver pulled about 870mA with an RCR123.

 

[Orion]

I have a QIII with a Cree Q4 and it shows about 120lm. It has a FLuPIC and on burst shows a little over 1A at the tailcap. If I remember correctly the stock driver pulled about 870mA with an RCR123.

So, running a normal CR123a, it may run it roughly 100 lumens, perhaps? I know that a lot of the newer Fenix lights and their lumen rating are considered by many on here as overrated. Do you happen to have any of the CREE Fenix flashlighs, and if so, have you check their actual lumens to what the factory states?

 

[Nake]

So, running a normal CR123a, it may run it roughly 100 lumens, perhaps? I know that a lot of the newer Fenix lights and their lumen rating are considered by many on here as overrated. Do you happen to have any of the CREE Fenix flashlighs, and if so, have you check their actual lumens to what the factory states?

Maybe more than 100. I only gained about 15 lumens when I went from P4 to Q4. I thought I should have got more, maybe I got one with a high Vf. When I get my Q5s I'll see what happens then.When I put a Q4 in my P1D CE I gained 30%.

I've got a P3D Rebel and a P3D with a Q2. Let me freshen the batteries up and I'll get back to you. I remember the Rebel being close to what Chevrofreaks graph shows.

 

[Orion]

I'd be tempted to get one of the single CR123 Rebels from Fenix store if it IS close to 175 lumens. I've heard others say they won't be though. I guess what I'm getting at is, if those other lights aren't obviously brighter than my Q4 CREE-ed QIII, then I may be best to spend the money on something else.

That's the delema. I look forward to seeing the results of your test, sir!

 

[jbosman1013]

the lumen ratings are in emiter lumens so you must factor lens and reflector loss. I think the 175lm emiter rating = 140 to 150 out the front/torch lumens. you also cannot run the rebels on turbo mode as long as the cree's due to heat.

 

[Nake]

Do you happen to have any of the CREE Fenix flashlighs, and if so, have you check their actual lumens to what the factory states?

Okay, here's the numbers I got. These numbers are after the battery has settled down and stablized. With the P3D Q2 and 2xRCR123 batt it showed 146lm. The Rebel, also with 2xRCR123 showed 143lm. With the P3D head I have found that if you use 17670, CR123s, or RCR123s the output is the same.
What I like to do is put a P2D body on the P3D head with a RCR123 for carrying, doesn't last long but a bright little light.
I put a fresh batt in the QIII Q4 and got 128lm. Maybe it needs to break in.

 

[bspofford]

I did it this way myself for awhile, then went to using a converted milk carton for a lightbox, like Quickbeam.

Didn't initially find any instructions for constructing a milk carton lightbox. Where can I find them? Thanks!

 

[Nake]

Didn't initially find any instructions for constructing a milk carton lightbox. Where can I find them? Thanks!

Go here and click on to Q&A.

http://www.flashlightreviews.com/index1.html

 

[Orion]

Okay, here's the numbers I got. These numbers are after the battery has settled down and stablized. With the P3D Q2 and 2xRCR123 batt it showed 146lm. The Rebel, also with 2xRCR123 showed 143lm. With the P3D head I have found that if you use 17670, CR123s, or RCR123s the output is the same.
What I like to do is put a P2D body on the P3D head with a RCR123 for carrying, doesn't last long but a bright little light.
I put a fresh batt in the QIII Q4 and got 128lm. Maybe it needs to break in.

If my board is at the same mA rating as yours, then it may be close to your figures as well. So, I'm thinking that even the two CR123a powered Rebel Fenix at 143lm wouldn't be nearly significant enough to warrant purchasing it.

Now, the Rebel Fenix that takes the single AAA may be worth getting just because of the very small and pocketable size. I'm not sure I like the "twist head function" though.

 

[Codeman]

Nake, did you notice a difference with lightbox? How much, roughly.

Bill

When I've been able to check my setup with lights of known output, I'm getting within 5-7% with my lightbox/lightmeter setup. The important thing is to get some known output lights to determine a conversion factor. I used a few Surefires along with the CPF benchmark lights. Those that participated in the benchmark test know the exact lumen output of those lights (including a SF A2), and Surefire's conservative ratings should mean my numbers, if skewed, are skewed to the low end.

You could probably come up with a conversion factor for ceiling bounces as well, as long as the room where you do the measurements doesn't change. The lightbox avoids that issue. But the downside ot the lightbox is that you are limited in what lights you can measure. Anything stronger than my Mag11 is too much for my meter's range (0-20k lux).