I mentioned the tube calibrated to a 1000 lumen Fenix several times you never stated other wise.
Like I’ve also said several times I’m confident any sub 5000 lumen light we can aquire will yeild similar results to each other. We managed 203 & 208 for our Cometas. What you need to do is try to whack some 6000 lumen plus lights on it and compare the results to Maukka. Obviously you can’t use a 25,000 lumen Fenix but Maukka, myself and others all hit around 20000-24000 for the X80, 13500-15000 for the X45 and 12500-14000 for the DT70, all these results are under the manufacturer’s spec.
TA has indirectly acknowledged the failing though. He’s stated that the diffusers absord a fixed percentage of light. If that’s 20% then a 1000 lumen Fenix light will read 800 lumens and a 10000 lumen light will read 8000 lumens. That half explains the increased losses as lumens climb. If the lights are floody (and TA has acknowledged tube walls before the 1st diffuser absorb light) then the lights will read 700 and 7000.
I don’t buy the claim Maukka recieves lights that are close to the manufacturer’s ratings and I get sent Ultrafire clones.
A thrower won’t hit the walls before the diffuser with much of it’s spill, a flooder like the X80 will shoot light out at an almost 180 degree angle, this light won’t travel through the diffuser cleanly and will bounce back at the torch and opposing side wall significantly, this is why I get 8000 lumens extra by bypassing the walls and sitting the X80-GT directly on the diffuser, less floody lights don’t get the same gains percent wise. This has nothing to do with being a certified light, TA could do the same test and it will get the same result.
The Cometa is a puzzle though, it really doesn’t like the tube. It’s really got me scratching my head.
KG, TA has gone above and beyond to help you. You agreed to a refund to make the situation right. You got your refund. NOW JUST GO AWAY . The rest of us a REALLY sick of your senseless drivel. JUST GO AWAY.
This is a long post I know, please read it all as it sums up few key points.
Here is the first quote I could find that I made about this, pretty sure I mentioned it a few other times as well.
Even a 7800 lumen light matches up very well, in fact you got higher readings.
There was also a comparison to one of Muakka’s tests around 7k lumens with one of your lights that matched up nearly perfectly with a floody light but I can’t find it right now.
It is simply not logical to see all of these numbers match up so well and then somehow think that a 16k rated light can somehow read 8k lumens due to the sphere when you already showed it reads pretty darn good up to 7800 lumens with another light.
When you see numbers like this we can’t throw out the majority in favor of the few.
Now some of the larger lights do seem to be reading less then they should but outside factors make a whole lot more sense then the sphere magically changing the entire calibration by 50% for 1 light.
Add to all of this the fact that your comparison to your ceiling bounce numbers prove that the sphere is actually more linear then your ceiling bounce numbers that you compared it to And maybe you can understand why I am having a hard time believing that the issue is with the sphere. The data simply does not point to the sphere as being the issue.
All the individual data-points provided say it is reading within reason on the lights that can be compared.
It is also reading linearly so that the readings should remain correct as lumens go up
And that there is no major discrepancy between flooders and throwers shown by getting matching readings with both.
When we know all of this, it is quite a stretch to say the equipment is at fault when a few higher power lights, that are known for being underrated, don’t get the numbers expected.
The fact is that this sphere is really very simple, there is nothing about it that should change as lumens go up, it should read with the same calibration regardless of the lumen output of the light.
A fixed and known percentage of the light is absorbed by the diffusers to match the calibration standard (aka, the muakka lights). There is nothing variable about it, it simply is what it is. Even professional spheres work on this same exact principal.
For example Muakka sphere is calibrated with a 110 lumen calibration lamp IIRC and so are most other professional spheres. They might take a reading with a lower powered standard to confirm linearity (Just like I do with my multiple lights) but they are not using 10k lumen standard light sources to calibrate these spheres. It is simply not practical or needed.
The losses and ratios are fixed and don’t change with different light outputs.
See if we can have an educated discussion on the matter we might be able to track down what is happening. :+1:
I responded to you before saying TA didn’t calibrate his tube to Fenix lights and his tubes are calibrated to Maukka’s reference lights. I think I remember TA answering the same way. If you read this whole thread, you will fully understand how the TA’s tube is calibrated.
Also, when the first batch of TA tube was shipped out to about 3 dozen of us here, we reported back that the tube was measuring much too high and TA never tried to refute our claims. But none of us were rude about it and many members here contributed alot of data for the fix. It took a few months but we resolved the problem in a very friendly and constructive fashion, when the end decision was for TA to calibrate his tubes to Maukka’s reference lights. TA also sent us repair kits for free (although many of us offered to cover his shipping cost out of appreciation). You can read all about it in this thread. That’s why when you just came out of nowhere and start bashing the product instead of working out the issues in a cooperative manner like we all have, some members might find that offensive, which led to some name calling. However, as I said it is completely unfair for you to attribute that to TA.
BTW, have you tried this simple method suggested by Maukka to diagnose. If the relative differences between your ceiling bounce measurement and TA tube measurements are consistent, then that means we can rule out your concern that TA tube is much more unreliable for high output lights. If the relative differences are not consistent, then that is good data for us and we need to figure out why.
You should also read Maukka’s post here that may help you understand how the light tube works and you concern about calibration.
You should really spend the money to buy a Maukka calibration light. It’s very reasonably priced and I am already on his preorder list. That way you can scientifically prove whether there’s a problem with your unit and surely TA will help you fix it like he has with ours originally.
Did you read my above post on this? You might of missed it in the long post a few posts up. It is working exactly how it was designed.
It absorbing a fixed percentage of light is by design, the number is closer to 80-90% if I had to guess BTW, I don’t have any numbers from before adding the discs with the calibration lights though.
The entire point of these spheres is that you don’t have to do the math on paper and they remove the beam shape from the equation.
The diffusers allow for this to happen by adding in the correction factor (something around 80-90% as a rough guess) without you having to break out a calculator.
This is not a failing or a problem, it is the entire reason they work at all and this is how ALL spheres work. They all have losses and they simply calibrate the spheres to the final setup.
Without the discs it would read about 5x+ as much as it does now. The discs are what makes it read correctly.
This is why a sphere is only as good as the standard used to calibrate it. You MUST have a trustworthy standard for calibration to work. Which is why we keep asking for Fenix or muakka numbers.
Why do you think this? This is not the case in the slightest.
He gets normal lights that are consistent and then measured them on his professional sphere.
That is the key, he then sends a lumen sheet along with the light letting you know exactly how many lumens it is putting out based on his professional sphere setup.
You can then use this light as a calibration source for another sphere, exactly the same way it is done professionally with ANSI spheres.
Right then why do all my 6000+ lumen lights measure approx 40-50% less than Maukka’s on your tube?
For example he’s managed 22300 for the X80 I get 15000.
Maukka is nearly hitting 16,000 Lumens at turn on with the X45, I’m managong a little over 10,000.
You can’t keep saying “manufacturer’s lie” as an excuse for everyone’s low readings then sell some more tubes.
As I said, These readings do not many a lot of sense but you can’t throw out all the other readings to justify these. They can’t both be right, it just doesn’t work that way.
A ~10% discrepancy, that I could maybe understand, it would be strange but possible.
A 50% discrepancy within a 25% output change on the other hand, that is just not logical.
Particularly when you add in the fact that the sphere was already shown to read linear with the ceiling bounce comparison. If there was a problem with it reading lower as lumens went up, this would be seen across the entire lumen output range, not only above 8k lumens.
That just can’t happen without some kind of active component to the sphere, which there is nothing remotely like that.
Can you please take a picture of you testing both of these lights? Including shots of the lux meter so I can see the settings it is set on. It is possible I suppose for the meter to have some kind of issue with a higher range of output but it would be a first.
We need to break it down to the details and go from there.
We will start off with double checking to make sure the sphere is being used properly. You most likely are using it correctly but this is the simplest explanation and thus should be the first thing ruled out.
Always start with the simple items and then work your way to the more complicated things.
Look I don’t care if a thousand Fenix lights all measure 1000 lumens on this tube, my point is a 1000 lumen Fenix light will read a 1000 lumens and a floody 10000 Fenix light will read 7000 lumens.
That said the same Fenix lights will test 1200 if Maukka tested them. (diffuser/pre diffuser losses)
This is why I recommend using the refund I sent you to buy a light from Muakka, it is a lot cheaper then fenix and more precise anyways since each individual light is measured.
No matter what you need something like that (Or a $1000 professional standard light) to calibrate anything you use for measuring lights.
I do not understand this? What do you mean by diffuser losses?
The losses are factored into the calibration, they are what makes the sphere read correctly.
We also do not know what the lights would read since we have no data to backup any of this.
I know that on my personal sphere I measured an MT09R and MT03 that have VASTLY different beam patterns but almost exactly the same internals and the readings were within margin of error of each other and these are ~15k+ lumen lights.
I also said this earlier but it must of been skipped over.
Haikelite had an MT09R measured on a professional ANSI sphere and got ~13K lumens at one point, using the same setup I measured it on mine and got almost exactly the same numbers once you factor in the new calibration.
This is another reason why I feel that the tube itself is working as it should. It is so darn simple there is just not much that could be effecting the readings internally.
Ok, see this is actually one of the most constructive and logical statements you have made.
You are saying that the entire calibration may be off, this is a much more practical option then thinking that the calibration changes depending on the output of the light.
It is also very easy to test, simply order a light from Muakka and test it yourself and we will all know for sure. I am VERY interested in what the results are.
There are four irrefutable variables I can think of that give a different reading between a flashlight tested on yours and a flashlight tested on Maukka’s/vinh’s/mine.
Diffuser losses. 15%
Pre-diffuser side wall losses. 5-30%
Where abouts the majority of light hits the tunnel wall after going through the 1st diffuser. 0-5%
Bounce back glare from very high Candela lights. 5-30%
