Well peeps, here is my mutidollar par meter under my diy led's this evening:
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I don't have a picture of the same reading on photone, because the phone holds the camera for the reading. But the reading in the identical position was 500. No bloody wonder that my plants have been compact, often droopy, and this year, badly tacoed for reasons I was not able to chase down. This damn meter was worse than a waste of money, it has signifcantly buggered up my attempts to get my PPFD and DLI in line. I have been toasting my girls for about three years now because I bought a shit meter hoping to get things right.
After having a good look at the photone information and trying the app, it is my opinion now that a grower is better off with Photone rather than buying a cheap so called par meter. The app is specifically calibrated for most recent cell phones, and the available calibrations for different light types looks comprehensive to me. The test results the company provides suggest that error rates are far smaller than anything a grower need be concerned with.
At any rate the par meter I bought is garbage. I am fortunate that it did not do more damage than it did. IMO anyone using one of these cheap par meters needs to either bin it, or calibrate it with a proper meter. Mine will be binned.
Oops, I forgot to mention that since I reduced light according to Photone, my four solos are un-drooping. The plants know even if the bloody meter didn't.