Texas_Ace BLF Calibrated Lumen tube / Sphere No math skills needed - Several spheres still available

10-2023 - I can still build lumen tubes to order

Prices for the tubes would be:

$185 + shipping for the 3.5”
$300 + shipping for the 4.5”

Ok, I have had several people ask me if I can make them a lumen Tube / Sphere like mine in recent times. My first sphere was simply too much work (literally months to get it calibrated) to make this possible.

Then the other day when testing some 20k+ lumen flashlights. I noticed that my sphere was starting to melt slightly.

So I decided I needed to make a replacement while this one still worked as a standard to calibrate the new one from. I had also been thinking of improvements for some time and finally got my hands on the right materials and tools to make this possible.

And thus, the Texas Ace integrating Lumen Tube was born!

It uses all the same principles from my earlier thread on lumen spheres

The only real change is in the diffuser. Instead of foam this time I am using some laser cut diffusing sheets that fit perfectly inside the PVC pipe. This makes it much more consistent and repeatable. Interestingly the direction you insert the sheets has a noticeable effect on the readings.

I also put another sheet between the 2nd PVC connection to further spread out the beam to remove any bias for throwers or other lights that these type of spheres can have issues with. The end result is a perfectly smooth wall of light hitting the meter. I fine tune the readings with magic

The best part of all about this sphere is that unlike every other sphere I have ever seen, the lumens will be displayed directly on the meter!

You will not have to run the lux meter readings through one or more calculations just to see what the lumen reading is, you simply stick the light in there and read the lumen directly on the meter. When I am taking dozens or even hundreds of readings a day this is a lifesaver.

In this picture the light is putting out 193 lumens, this same light and mode reads around 195-196 on my old sphere for reference. I can get that closer but have just not had the time with all the mt09R mods and frankly don’t care since I only give it a ~10% accuracy rating anyways.

So I am planning on making a 1 time batch of these spheres. They will all be calibrated by me with my sphere so the readings will be comparable.

These spheres will come with everything in the pictures
The PVC tube itself, able to fit up to ~89mm reflector lights
HS1010A Lux meter like mine
a range of centering rings for different size lights
calibrated to match my sphere within ~5-10% or so (to give some wiggle room since it is impossible to get things perfect)

I have tested this sphere with lights up to 25,000 lumens and it should in theory be able to read well over 100,000 lumens if the light would fit in the tube, although you would have to worry about melting something at that power level.

Ask anyone that has tried to calibrate a sphere from scratch, it is way harder then it sounds. My sphere took me 6+ months and countless lumen readings before I was happy with the readings.

The lumen tube is far from my idea, The credit for the basic lumen tube setup belongs with BLF members from long before my time.

Making it an “integrating lumen tube” by adding the diffusing sheets and the centering rings to make the readings more consistent light to light was simply my evolution of the idea.

The addition of diffusing disks inside the tube also vastly improve the consistency from light to light and removes the advantage that throwers have classically had in PVC light meters.

Thanks to JasonWW for the illustration.

3 Thanks

$175 - 3.5” version List:*

1- Texas Ace
2- shirnask - 3.5” - Paid - Shipped
3- steel_1024 - 3.5” - Paid - Shipped
4- emarkd - 3.5” - Paid - Shipped
5- Terry Oregon - 3.5” - Paid - Shipped
6- slimkango - 3.5” - Paid - Shipped
7- peabody - 3.5” - Paid - Shipped
8- charles lin - 3.5” - Paid - Shipped
9- JasonWW - 3.5” - Paid - Shipped
10- Krash610 - 3.5” - Paid - Shipped
11- John-Galt - 3.5” - Paid - Shipped
12- Blazer296 - 3.5” - Paid - Shipped
13- teacher - 3.5” - Paid - Shipped
14- WillyD - 3.5” - Paid - Shipped
15- miswas - 3.5” - Paid - Shipped
16- Muto - 3.5” - Paid - Shipped
17- scannerguy1968 - 3.5” - Paid - Shipped
18- nechronius - 3.5” - Paid - Shipped
19- leroycp - 3.5” - Paid - Shipped
20- Dividedhead - 3.5” - Paid - Shipped
21- lights_and _pieces - 3.5” - Paid - Shipped
22- Lumens Industry - 3.5” - Paid - Shipped
23- Bob_McBob - 3.5” - Paid - Shipped
24- inrealtime - 3.5” - Paid - Shipped
25- Ozythemandias - 3.5” - Paid - Shipped
26- beam0 - 3.5” - Paid - Shipped

$235 - 4.5” Version list:*

1- SKV89 - 4.5” - Paid - Shipped
2- Newlumen - 4.5” - Paid - Shipped
3- Newlumen - 4.5” - Paid - Shipped
4- Newlumen - 4.5” - Paid - Shipped
5- staticx57 - 4.5” - Paid - Shipped
6- Micael - 4.5” - Paid - Shipped
7- KawiBoy1428 - 4.5” - Paid - Shipped
8- jmm244 - 4.5” - Paid - Shipped

For a 6” version the cost is extreme, which is why I did not even consider it before. It would be ~$375 + shipping, which would not be cheap at all, it would be a massive box and take up a ton of space and weigh a lot as well. Although the option is on the table if someone is interested.

I really like the 3.5” version myself, it fits most lights and does not take up a ton of space.

So I will assume everyone on the list wants the normal 3.5” version unless you tell me otherwise.

I can ship these internationally as well, contact me for a quote.

Also these have been tested from ~5 lumens to ~25,000 lumens and should be able to read over 100,000 lumens if the PVC didn’t melt lol.

All of the LED tests in my signature were done on my sphere like this.

I’m in for one

Im in for one. Is it large enough for a big head like blf gt?


Maybe it’s not really important, but it might be nice in the interest of full disclosure to say in the OP that the “integrating pipe” is not your original idea. Others have been doing it for years. Although, I’ve not seen it done with diffuser material like you have. Thanks for offering this to the community!

Updated the list.

Sadly no, even 4” PVC is not big enough for the GT and getting larger is very very expensive and somewhat hard to find locally. I considered stepping up to that size myself but it was just not worth 4x+ the price.

This can support up to a 3.5” (~89mm) light, which I find covers the vast majority of lights I want to measure. Thus far the GT is basically the only light I have had that would not fit, the TN42 would be just over as well but I don’t have one.

If someone wants a custom larger sphere setup with larger PVC I can do this, it will just cost much more.

Yes, the lumen tube is far from my idea, I never intended for it to sound like it was.

Making it an “integrating lumen tube” by adding the diffusing sheets and the centering rings to make the readings more consistent light to light was simply my evolution of the idea.

I do not know how Texas_Ace can get so much done, has he cloned himself?

Very thankful to have him and his services in our Forum!


:student: :+1:

Out of curiosity for me and maybe others. How much would the lumen tube cost us for the bigger version to accommodate the blf gt? I don’t think this will be the last time companies will be making heads this large. I already have a few lights from acebeam and thrunite that are 4 inch. I believe olight and manker will also release some large head lights.

This looks very neat! I definitely do not NEED one, but the WANT is strong! Must think…


Thanks TA!! Sign me up please. :+1:

Is this design useable with right angle lights?

Vry Nice—-I’ve been using DC Fix in my light tube—-I still have a multiplying factor but my results are much more reliable and consistant

Hmm, that is a good question. I know the PVC itself was several times the price. If there is interest I will go to a specialty plumbing supply store and see how much it would cost.

Remind me to check into this if I forget, this week is going to be VERY busy for me.

Just let me know if you want me to add you to the list. If you end up sending me the L6 to mod I could ship them back together.