Yeah, I think Lexel said the early versions had no thread locker. Then they started using a light colored thread locker that was pretty weak. The latest ones use a red thread locker and are really hard to break loose.
They should read basically the same, although the way the light bounces around in the first chamber can effect things slightly, although this is usually due to the throwers having larger reflectors.
Congrats steel… it’s good the TA arrived safely… lumintop lumen are not consistent… I don’t know how they measured… I don’t think it really 3500 lumen… probably around 3000 lumen @ 30 seconds…
I'm now the owner of an HDS Systems Executive (200 lumens tested) and a modified Convoy S2+ from PFlexPRO (607 lumens, tested).
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THE HDS Systems Executive did not come with a calibration report, only a receipt stating it was 200 lumens (in addition to their website stating all lights are tested).
The PFlexPRO came with a calibration report (gotta love the potting sample in lower right):
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Unfortunately, the results of testing both on the TA lumens tube resulted in readings that don't make sense.
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HDS Systems
spec 200
TA Tube: 349
correction factor of .573
Note, I had an email discussion with HDS Systems (Henry Schneiker) to make sure initial turn-on (high) is where he measures the output. It was.
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Convoy S2+ (PFlexPRO)
spec 607 @ 30sec
TA Tube: 790
correction factor .768 @ 30sec
.573 and .768 is a BIG discrepancy. I was hoping to see both lights give results that were very close. The Convoy seems closer to what I expected.
I'm stumped.
The only other light that comes really close to the PFlexPRO correction factor would be my modified Maglite. Mat claims the 5,000 lumens is out-the-front.
And this is the problem that I and many others have had with DIY spheres. You can get 10 flashlights all rated to given numbers but get very different relative readings. This is why I gave up on using flashlights for calibration.
What tints are the lights?
HDS has an ANSI calibrated sphere but they do not take the readings at the ANSI 30 second mark? That seems odd.
PFlexPRO says his sphere is calibrated with flashlights IIRC.
This is why all DIY spheres have to average the data from as many sources as possible to try to find a common middle ground that is semi-accurate.
This is also why I will never understand why anyone lists the lumen value on a light down to the single digits, they simply can’t know that.
I honestly don’t know what to think, I thought the calibration I had was pretty good when I started this as do many others but it seems a lot of us are wrong.
I’m just waiting for you get your test lights back from Maukka, that he measured against his proper reference light, then test them across your remaining spheres to find the proper correction factor. That will probably be good enough for me. :+1:
I think it’s just human nature for us to want to see high lumen numbers from our lights. It’s hard to accept that a light that we thought was doing 9000 luman may actually be doing closer to 6000 lumen. Nooo! Say it ain’t true! Lol
It’s like we’re living in The Matrix and we’re starting to emerge from our pods and seeing the real world for the first time. Lol
Matt’s homemade integrating sphere was based on TA’s calibration if I recall correctly. So we shouldn’t go by that.
If PFlexPRO is not using a NIST calibrated reference light, then we should probably ignore those results as well.
HDS Systems uses turn on lumens? How odd. I wonder if he just verifies it meets the minimum 200 lumen specification? If so, then it could actually be more than 200 lumens.
Indeed, the only reason I trust Maukka’s numbers more then most is that he has an expensive standard lamp to compare against. This is the single most important factor to a quality sphere.
I am very curious to see what the numbers work out to. Some early data says it should agree with what most others are seeing in the high .6x range.
This is probably what they’re actual numbers are showing. It doesn’t mean it’s super exact. So you have to take it with a grain of salt. If it says 842 lumens then you know it’s probably 840 ish. Maybe even think of it as the mid 800 range.
Don’t beat yourself up about this. It’s not that big a deal.
Yeah, I know that and it doesn’t bother me directly so much as what the novice members among us think when they see those numbers. It propagates a false impression of exactness that we simply don’t have the capability of achieving.
For me the biggest attraction to your sphere project is the fact that a group of people here will have a standard to compare with each other - not some exact number.