Thx ChicagoX, I'll try w/just two elbows. As an update, I've edited post #7 w/pics. For now, just as a POC for myself, I skipped the step down adapters and just placed the sensor at the lip of one end. I placed a piece of glass on the light end to hold the light in place. I noticed that I'm allowed some flexibility w/the placement of the light w/out affecting the reading drastically (the sensor however will read a bit higher once centered in the step down adapter).
Of course there's consideration to be given to the semi-glossy surface of the PVC so I may look to coat it w/IS paint.
Anyways more experimenting to come.
EDIT: Thx Langcjl, let's see... I mean, I don't mind criticisms as truth be told, I'm not even sure this would work but I don't think the forum should be disparaged on my behalf...
Thx Boaz! It's all good man, as I said, I don't mind criticisms levied at me/my ideas but just didn't think it would be fair to direct at the forum. Appreciate the clarification! :beer:
Sounds like a good idea to me. Something like a sink trap would completely exclude any direct light. But losses would be high. Would be good for the silly high powered stuff though.
Repeatability is far more important than absolute accuracy for what we're doing.
So here's the deal, I was afraid that this might favor throwers, and perhaps it does to a very light degree and as much as I remain a little skeptical myself, the readings keep telling me that I just might be on to something.
I took a few more measurements of most of my lights and they are all within % of claimed ANSI or mfg claims (and again using the same set up as above as I didn't have time to sand and paint yet).
I think these two test subjects are the clearest example that this might work:
This is the eGear Focus Control headlamp, it can be focused from flood (left pic) to spot (right pic) and in spot mode, it only increased the reading marginally:
This is a LumaPower XR-E R2 w/TurboForce Kit that casts a pencil beam sized hot spot (check my beamshots threads in my sig for beam profile) and if this contraption did favor throwers heavily, then this reading should be much higher but I think it's fairly relative for a XR-E reading:
L: Lux reading | M: stepped down to show beam profile | R: diffused light at other end
I don't have time right now to post the rest of the pics but the full album is here in case you want to take a look. I tried to include most of the light in the pic so you can identify them (EDIT: forgive the bag in the pic, it's acting as a ballast to hold down the pipe).
I'm sure the readings will be different once I sand down and mount the sensor in the center of the pipe but at least this seems encouraging no? More to come!
guardedlyoptimisticTim
(sorry Foy, I needed to just do this at least once during my time on this forum, but please know it's in your honor!) =o)
And, I also commend you - your pipe dream seems accurate. In fact, I'd like Match to chime in a bit more on this project. Specifically, does he think the light is sufficiently integrated? Your results thus far suggest that it may be. If it is, I'm thinking I would rather build this than a sphere.
OK, so I actually haven't done any further fiddling with it and literally been using it as is w/out the adapter. Where it deviates from my original requirements is that it will be affected by ambient lighting so I need to take measurements in a pitch black room. While I don't have a baffle to deal with, thx to feedback from a member, I found out that ambient temp will affect the readings. So each time before I take readings, I'll first use a Xeno G10v2 (as Xeno uses ANSI values and it immediately runs nearly perfectly regulated on medium) to calibrate the sensor's position to match as close to 158lms as possible. Then I'll check the other levels to see if they're close to 480 and 10 on High and Low respectively.
The PVC (lms) column is what I've measured for each light. The output is measured in lux but wouldn't be far-fetched to call it lumens as the readings are pretty close for most of the lights. As expected in SureFire's case, they are known for underestimating their lumens and my readings corroborate that. Judging by the measurements, Sunwayman is also a little on the conservative side as well. All my measurements are done at 31seconds after turn on but of course it's not known at what time the manufacturers take their readings since it can be done anytime between 30secs - 2min.
As you'll see, it doesn't necessarily favor throwers. Case in point, the T40CS is near~47K lux and the V60C @ ~36K lux but yet the V60C registers 904 lux (lms) vs. 814 for the T40CS.
While I wish there was some engineering formula I could provide to calculate what is happening to the output after three pipe bends to produce these results but in a way it's been great not having to. I'm now able to consistently reproduce comparative WISIWIG (What I See Is What I Get) figures of how one light is faring vs. another.
The real nice surprise aside from the Sunwayman V60C were the ThruNite TN 10 & 11 as those readings were taken on only 1 x 18650 each, I'll post 2 x 18650 config (including step down) when I get around to them.
Anyways this has been a fun experiment for me and useful for comparitive purposes. Anyone else care to give this a spin? Assembly takes all of 5 seconds after you get the 3 x 90 deg. elbows.
I put the PVC LMD into action with my latest review:
http://www.youtube.com/embed/VR1Aeqe1A24
With this, I am now able to provide real time lumens measurements with my runtime testing so that for non-regulated lights, it allows one to get an true idea of real expected output for the duration of the run.
Hi rennsman, sorry for late reply, my alerts keep randomly getting changed for some reason I didn't notice your reply 'til just now. That looks to be a very interesting oscilloscope.
Just two q's for you:
1. Would you happen to have any samples of graphs output from it
2. Is it enough to cover the entire frequency one might expect to be generated from flashlights using PWM?