I was watching a video by Selfbuilt yesterday. I really enjoy his reviews. It got me to thinking it would be fun to be able to test my own lights & such. I bought the meter below. I know that it measures Lux… Now I know nothing about it. Scaru pointed out that I need to keep my throwers 1 meter away when doing my readings. If anyone could enlighten me as to any other tricks to testing these lights. I would appreciate it. One question I have is how is a simple way to measure lumens?
Actually that is not what I pointed out. ;) I suggested measuring your throwers at distances further than 1 meter and then calculating back. This allows the beam to fully colimate.
Usually you get better/more accurate readings when you measure further distance and calculate back to 1m. Example measure at 10m and multiply it by 100.
More than a meter… my bad…
The labor-intensive way is to build your own integrating sphere (there's threads about that here and on CPF).
The way I do it is measuring the light bounced off a white ceiling: I aim my luxmeter at the ceiling at a fixed distance (about 1 meter in my case, the actual distance is not very important, just that the distance is always exactly the same), aim a flashlight at the same place on the ceiling (the distance of the flashlight is not that important, I tailstand them 10cm next to the luxmeter) and measure the lux. You need to measure at least one flashlight with a known lumen-output this way to compare all the others with, and that is the tricky part: no flashlight of any brand,type,battery has exactly the same output so in the end your reading is always an estimation (unless you have a calibrated lightsource, I don't know anyone who has one). My reference is my Thrunite Ti on a fresh duracell alkaline, which is supposed to be 60 lumen. And I hope my lumen guesses are not more than 10% off the real value.
+1