Sold/Expired Lumens tests?

OK - lumens.
I got a cheapo (but well recommended) luxmeter.
People ask - how many lumens??/
I don't think its that easy!!
Conclusion is that its OK to measure relatively, but not objectively.
Here are some shots of a test I did tonight, as controlled as I could easily devise.
Box to hold the meter sensor with aperture to fire the lighjt through at the same distance each time. Camera set to auto exp. Camera on tripod, remote shutter release, pressed when I thought I had the highest reading on the meter (not easy as it fluctuates with the slightest movement)
Meter set to 100x lux.All lights run from standing cells, not recharged for this test.
Then my second problem. If I see 1000 lux on the meter at 100x scale, that means 100,000 lux - WOW!
But the meter measures up to 50,000 lux - duh?

Here are the pics - lots....The last pic shows the box set up most clearly.

2Li C, AW switch, 5761 bulb



9 NiMh 1164



2 x (4x14500) ROP HI



2 Li C Tri Seoul P4



4x14670 Nflex quad P4



1 L1 D ubercell Seoul P4



3x17670 1185



Mac proto 3 x 17650 Seoul



Mac aspheric 1C



uberLi D tri P4



uber Li D P4



7x NiMh 64250




SF M6 6x rc1231185




UF 500 2x18650 1111




uber Li D Q5



uber Li D Q5

Im confused..are you selling anything??:thinking:

Cuso said:

Im confused..are you selling anything??:thinking:

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Not really confusing. Just the wrong forum. More appropriate in General Flashlight Discussion.

Bill

Not sure some of the reading add up. Uber P4, is that a one led light? If so it seems to have an unusually high lux number compared to uber tri P4, or some other lights.

Bill

I'll Take It!

Bullzeyebill said:

Not really confusing. Just the wrong forum. More appropriate in General Flashlight Discussion.

Bill

Click to expand...

Thanks Bill - I goofed here and this should be in another place - mods can you help?
The whole point of the test was to show how (un)reliable a non lab lumens test probably is!

jcompton said:

I'll Take It!

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Are you taking the luxmeter? I'll take the lights. :naughty:

Actually I'm selling the high tec light box

Actually, the lightmeter box that Quickbeam set up for his flashlightreviews.com site has been very reliable compared to an independant lab's results, LSI, using a high end lab intergrated sphere. See the Lightmeter Benchmark thread in the battery, etc forum. Click on "threads of interest". Other CPF folks, chevrofreak, for example has worked up their own lumen testing/comparison setup's that are also fairly reliable. Your setup does not look like, from the getgo, anything like Quickbeam's. Have you followed his advise about setting up a light box. See his web site. I use a very simple method for comparative purposes, using a ligtmeter, an LM631 to record bounced lux figures off of a ceiling, getting very consistant results, and have never gotten results similiar yours where a simgle led shows unusually high numbers, compared to very strong incans. If I am wrong about your setup relative to being not similiar to Quickbeam's in construction then I apologize.

Plasmaman, thanks for the time and efforts you went to in setting this up. I can see a couple things I would suggest for improvements based on your tests.

Closing the box lid to include lumens in lights with more spill. It seems the bounce method prior to a reading is the only way to discount hotspots....which for those of us who care about hotspots and throw (vs. overall torch lumens as in an I.S.) is always going to be an issue. Other thing is to have a fixed, centering cradle so light is same distance from box, and not moving in your hand.