Hi guys,
I plan to build my own integrating sphere. All the components are ready, just waiting for my free time. I need to know what is the best method to calibrate the sphere? Are there any “standard” bulbs/flashlight for it?
Thank you,
Clemence
I just used lights that were tested by other users here. I used a couple to calibrate then tested against a couple more to see if numbers were close to tested lights here. Takes a bit of time because there is a bit of variation from light to light just in the emitters and such. The more lights you have that are not modded (so that match exactly to what other users have tested) the more accurate you’ll get your sphere. My estimate on mine is 5% variation which is partially because I dont have an expensive lux meter that’s calibrated better.
How about this: It’s easier to buy 50 pcs of whatever LED from a reputable manufacturer/distributor in certain bins? Since most of them are using 25C and 85C Tj it’s easy to simulate. I know there will be some variations too but it’s cheaper and supposed to be simpler too. I’m afraid the hot spot of a reflector/optics will vary the readings. Have anyone tried this before?
An easy way to calibrate an integrating sphere is to use the formula:
lux x area (in square meters) = lumens
The method is described here.
and also here.
Thx 60545,
I’ll read it