Light meter help for a newbie

[Greenegreens]

Thank you everyone. You saved me some money and cleared up some confusion for me .

[Bracketh]

I’m actually finding myself running the same. Maybe a little more based off of nickys DLI thread but not by much.

@Greenegreens I also calibrated the Photon app to my manufacturers par chart.

[4204life]

I tried to calibrate mine. Every chart I found were for led lights. I use hps for flowering. Could not find a chart for that light. So I just went with it.

[Greenegreens]

How do you calibrate off of your manufacturer

[Bubbala]

A brief overview of the acronyms and how they work together. Also from Nicky’s thread.

Start using DLI

OK, I’m still learning this, but they say you only really know it when you can explain it to somebody else. So I’m practicing on you @Audiofreak Lux measures Lumens. Lumens are just all visible light. Lux meters are used for people lighting, but gives a general idea of how bright a light is for plants, just based on Lumen intensity. This can work if you already know the light is for plants. Plants don’t used the whole visible spectrum however, and the spectrum of light important to plan…

The little i next to them in the Photone app has some nice explanations too.

[Bracketh]

In the apps settings there should be a calibrate function. There is also a video explaining how. If you have and trust your manufacturers par chart, place your phone at the manufacturers distance then hit calibrate and punch in the number they have for that distance.

Ex. My manufacturers light said 1253 @ 12in in center. So I placed my phone at 12in, cranked light to 100%, centered phone in tent at highest par reading I could get @ 12in, then hit calibrate and entered my 1253 #.

Now when I move my phone to 14 and 18in it matches my manufacturers chart, really closely.

@4204life if you know someone with a meter you could calibrate using that instead of chart.

[Bubbala]

How close was Photone to your manuf par map @Bracketh ?
My HLG is discontinued, but from what par map I can find I’m reading about 300ppf over even on full sun setting. More like 800 over on full spectrum, which is what I believe this 600Rspec is.

[Bracketh]

I can’t remember specifically off the top of my head. I can test tonight once lights come on. Once you have calibrated you can turn the calibration on and off. So I would be able to compare.

Also different diodes will give different readings. Such as my ion grid I have it calibrated with is 301h. But I have an Ion board with 301b, and it does not match manufacturers par chart with it calibrated currently. However I use an different phone calibrated for that light to measure when I use it.

Phones also have different cameras and lenses so each phone model may calibrate slightly different.

[Bubbala]

Ok, being able to switch back to default was my next question, good to know, thx!
Worked like a charm. I imagine quite a bit of variation comes from the reflective tent material as well. I’m sure not pulling my light out just to set it, and I believe the par maps are in an open environment with no reflective material.

[Bracketh]

I was under the impression to try and calibrate it with your tent zipped up as much as possible.

[Bubbala]

I agree @Bracketh . I was just commenting that the manufactures’ par maps are created out in the open I believe, which would make our readings appear hot by comparison at first when we’re taking them in a tent, since we are taking readings in a reflective area, and they did not.
But yes, I agree that to get accurate readings, we need to take them in the tent just as you said.

[Greenegreens]

The chart that brackach posted . Is that for autos ,photos , or both .

[Fiefie]

It just general guidelines…the dli charts are more specific…however you must convert the dli to ppfd… there’s calculators out there.

[Bracketh]

Like fiefie said just general guidlines that give you overall parameters to roughly shoot for.

[Adam1jam]

I have that one and like it, very simple to use.