I am constructing an integrating sphere and lumen tube so I need a known lumen light source.
I can get in the ball park with some pain in the butt calculations but that is not good enough.
Neither of these will be dead perfect but, much closer than anything I currently use and I can construct both for very little money.
I have a few lights that have not been modified that if anyone else happens to have and knows it's lumen output I can always use the same cell and probably be very close or if anyone that already has A sphere constructed, I live in upstate South Carolina, I would be willing to ship one of mine and pay shipping both ways if someone were willing to get a reading for me.
Lights I have that have not been modified at all, totally stock.
Jetbeam C8
Thorfire VG-10 <----- This will be stock only for another couple of weeks lol.
Rofis KR20
Rofis TR20
I have a decent variety of 18650 cells and have about a dozen 30q's on the way. Half should be here tomorrow.
If you got multiple lights you can get a good calibration
The better quality and trusted manufactor ratings the better
Measure tailcap currents they should be consistent to the claimed lumens and LED
Know the Emitter bin
Can the manufactor lumens rating be trusted
Check the lights you got for reviews with sphere measurement
Use fully charged high drain cells
Bypass springs is always a good idea
Now measure all the lights and compare reading to the figures you got from manufactor and other reviews
If you do this for 5 lights right you can get within a few percentage error
Yep I do believe that should work. What cell did you use in the updated VG-10 please?
And wow, that is a pretty decent loss in output for an upgrade. I don't have my box anymore but it seems like that comes lower than stated.
Yep they say 847 lumens, they missed that mark.
I still like my VG-10 a lot, I wish I had gotten 10 of them when the holiday sales were going. I have noticed that my Jetbeam C8 appears brighter and it is nowhere close to it's stated lumen output of 1k.
Once I get these completed, (really just waiting on the meter) I can see what the Jetbeam is kicking out. I like it as well even if it does come in low. It is just small enough to keep anywhere and still bright enough to do what you need. And some nice features to keep the heat down.
Terry, you’re welcome to borrow anything I have if it will help. W. Greenville here so meeting you somewhere shouldn’t be a problem I think my best candidates would be either of the 2 BLF M24’s (little used so both should still be on-spec), Maglight Pro 2*AAA(100 lumens, seems I recall someone saying they’re dead-on that spec), or you can check your results against my BLF Integrating Sphere (shamefully unused yet but I tested the meter which is working ). Got several others but I have reservations about their exactness of calibration. Handful of BLF 348’s to average out; might be useful, dunno.
Llol I knew you were in S.C. but didn't know you were that close.
I hope to have the tube finished by next weekebd. If I had normal days off like most people could finish it sooner. Once I get it to the point of measuring FT-candle I will try the numbers on the Thorefire and see how it comes out. I am suppose to be off that Friday, Saturday, and Sunday so I would still have plenty of time for a road trip.
We’re just a good thrower’s beam distance apart I think We ought to do a coffee together someday anyhow (grits optional). Mid-Sundays are taken but my schedule is pretty flexible otherwise given a bit of lead-time to plan with. PM me if it looks like we can do something- Have van, will travel :sunglasses:
As soon as we finish (almost done) the re-tool and then they want to waste our time and cjange from our 12 hour rotation to a stright8 hour 5 day week.
LMAO we told them (them being totally new never seen what we do department heads) we provide carpent, headliners, and sound barriers to every American based Japanese Auto manufacturer which basically makes it impossible to shut down on weekend. But just like the last 2 times this happened they will have to learn the hard way.
Anyway once that smooths out a bit I have a ton of personal and vacation time. And a massive 2005 Dodge Durango lol seats as many as most vans.
Okay... never saw this coming. I got my (what I am going to call light box lol cause it ain't no sphere) just about ready to test. My meter does not arrive until tomorrow but I have several electronics apps one of which measures light from the sensor on my phone. That's not a problem today would jist be testing anyway.
Problem is that I shot what is rated at 300 lumen into it and the damn thing glows like a lighthouse.
Now I might be wrong but if this thick thing glows light is not bouncing and evening out, it's escaping?
If I'm wrong someone please say I am lol.
If I'm right options please. Last night off until Monday, gotta have at least this complete before then.
It is not as far off as I had thought, I got 623 lumen from totally stock Throfire G-10
That's only a 41 lumen difference from the 664 old4570 got and I am using a mobile phone app that is using a tiny light sensor on the front of my phone.
This is my light tube, made from a 4” diameter “P” trap.
I used this as it was a quarter of the price of me buying 3 separate 4” x 90” degree bends :+1: and this is “budget” light forum
The inside is painted with matt white paint, the light sensor is held in place in one end in a rubber blanking cap & the lights are held the other end in 1” thick pieces of foam, blacked out & with holes cut to accept various diameter heads.
It seems to give reasonably accurate & repeatable results (being repeatable in terms of measuring before & after mods is probably more important than accuracy in my opinion, well to me anyway).
I have compared my readings with other members who have posted results on stock lights & with manufacturers claims.
I think my best candidates would be either of the 2 BLF M24’s (little used so both should still be on-spec), Maglight Pro 2*AAA(100 lumens, seems I recall someone saying they’re dead-on that spec), or you can check your results against my BLF Integrating Sphere (shamefully unused yet but I tested the meter which is working 
). Got several others but I have reservations about their exactness of calibration. Handful of BLF 348’s to average out; might be useful, dunno.
We ought to do a coffee together someday anyhow (grits optional). Mid-Sundays are taken but my schedule is pretty flexible otherwise given a bit of lead-time to plan with. PM me if it looks like we can do something- Have van, will travel :sunglasses:
