Understanding light.

This is an awesome thread! Thanks for starting it.

Just to show everyone how decent a phone can be for measuring light levels. I tested a few grow areas at different lighting levels with both my 2 phones (both android both samsung but 4 years apart in tech) and a "professional" light meter.


Seedling and clone area. 5000k led



Small tent 2700k led



Large tent 3000k 2x240w quantum boards. If you can't make it out the phone says 94407

The accuracy of both my phones compared to the actual light meter is within 1% or 2%.

I've rented an Apogee Par meter before but the numbers between my OnePlus 6t and what the Apogee said were vastly different. My phone caps out at 32767 lumens while my DIY light under the Apogee was around 1400ppfd at 12 inches. My phone is still capped out at 24 inches with 32767.

The calculators aren't really accurate and don't account for how the light is configured so even if I input Bridgelux data from their sheet it still isn't an accurate representation. 80 cri and 3000k but it won't tell me like the PAR meter does that at the edges my light falls to around 1300ppfd at 12 inches.

If I was just going to but someone's light I'd probably still measure with an Apogee because of all the significant different variables from my grow room vs 'X' light manufacturers testing facility. I can read the plants but a $400 meter paired with $$$ lights seems sensible if you're already spending that kind of money to begin with.

Then again I'm looking for DLI in my rooms and not just how how high to hang my lights but also adjusting wattage as well.