Lumen tube considerations

Off-topic Chatter
6

A sphere is the way the pros do it. But it needs to be large to deal with a large powerful light.
Tubes are more compact and, with the right amount of fiddling, seem to be the method of choice lately.
Depending on the design, there is often a difference between the measurements for throwers vs floods of the same Lumen output.
This can be mitigated by careful use of diffuses and tube lining.

There are several threads about DYI Tubes, boxes, Etc.
The key to all builds is to have a known standard to calibrate the measuring device against.

Maukka sells calibrated lights. But they are low powered.
His thread with several builds:

Texas Ace Calibrated Lumen Tube:. Widely used by many in the BLF and other forums.

My DYI Adjustable calibration Lumen Tube

And a few more from djozz

And others

A short thread discussion about a high powered reference and the linearity of the measuring devices.

There are many more. It would take a bit of searching to root them all out.
All the Best,
Jeff