Lux/ppfd/DLI chart for Autos?

[pg2052]

Also, there's an app for iphone called Corona that has a DLI and PPFD meter: https://growlightmeter.com/

This guy on youtube runs a comparison to a real Lux meter, so it seems the app is pretty solid and will get you close for just a couple bucks. Note that you have to put a piece of white paper over the camera lens when using or the numbers will be all out of whack. I think the app actually makes note of that little hack now, but didn't when I first got it.

 

[Death The Cultivator]

That's 800g/m2.

Lux meters are also good for measuring spread if you can't get a par meter. I'm not for changing the light intensity as they grow myself; I just spread my lights evenly over the area and let them be.

I mapped my distances rather than various intensities as I don't dim my lights personally. @elcoloan bought a PAR meter and saw the discrepancy between Lux values and Par values. The accuracy isn't there without the proper SPD conversion but people have been growing without meters for years.

 

[Srfr]

Found myself admiring some guy's autos on growdiaries and this is the schedule he follows...so I'm going to do the same next grow.

AUTO FLOWER LED LIGHT INTENSITY
Recommended LED PPF/PAR Values / DLI Based on 20 hrs. of light.
Seedlings 150 - 200 umol / DLI 10.80 - 14.4 moles per day
Veg up to 9" 450 umol / DLI 32.40 moles per day
Early bloom 500 umol / DLI 36.00 moles per day
Mid bloom 650 umol / DLI 46.80 moles per day
Late bloom 750 umol / DLI 54.00 moles per day
Ripen 400 umol / DLI 28.80 moles per day
*** Use extreme caution going 700 umol or higher @ 20 hrs/day this could cause leaf burn***

Interestingly he's driving them a lot harder than SGS's numbers. I dont suppose you have a link to this guy's diary @pg2052 ?[/QUOTE]

 

[Srfr]

Also, there's an app for iphone called Corona that has a DLI and PPFD meter: https://growlightmeter.com/

This guy on youtube runs a comparison to a real Lux meter, so it seems the app is pretty solid and will get you close for just a couple bucks. Note that you have to put a piece of white paper over the camera lens when using or the numbers will be all out of whack. I think the app actually makes note of that little hack now, but didn't when I first got it.

I've downloaded this but it's all over the place. I'll need to try and calibrate it later. I'll let you know how I go.

 

[pg2052]

I've downloaded this but it's all over the place. I'll need to try and calibrate it later. I'll let you know how I go.

Hmm. The only thing I had to compare my numbers to was the HLG light specs and they came out pretty close. Let me know how it shakes out. Sorry if I gave you a poor lead

 

[daylight]

Korona app is pretty good, I use it all the time.

 

[Srfr]

Well I've almost given up on this as every chart and conversion gives me different numbers. I have found some good wattage/height/lux for my Unit Farm Led however so not all is lost. Thats what I was trying to do anyway. The Korona app was all over the place and I had difficulty calibrating it. I tried callabrating it to the light's ppfd rating at 18" but that seemed to give odd readings. I tried the LUX callibration too but that was actually worse! I'll come back to all thiis when I find better info.

 

[Death The Cultivator]

Well I've almost given up on this as every chart and conversion gives me different numbers. I have found some good wattage/height/lux for my Unit Farm Led however so not all is lost. Thats what I was trying to do anyway. The Korona app was all over the place and I had difficulty calibrating it. I tried callabrating it to the light's ppfd rating at 18" but that seemed to give odd readings. I tried the LUX callibration too but that was actually worse! I'll come back to all thiis when I find better info.

Gotta have a PAR meter for accuracy or a spectral distribution conversion factor to turn PPFD to LUX. Smartphone sensors aren't equipped to measure light in a Horticulture setting.

You can always rent a meter, get you're PAR maps plotted, then send it back. Imo, you either have the manufacturer suggested heights or you use a Horticulture grade meter like an Apogee or Sekonic.

 

[Srfr]

Gotta have a PAR meter for accuracy or a spectral distribution conversion factor to turn PPFD to LUX. Smartphone sensors aren't equipped to measure light in a Horticulture setting.

You can always rent a meter, get you're PAR maps plotted, then send it back. Imo, you either have the manufacturer suggested heights or you use a Horticulture grade meter like an Apogee or Sekonic.

I hear you! I think I'll just keep doing what I'm doing (like everybody else) and wing it. I do take a lot of notes and this run has been my best so far at day 22 so I cant complain!

 

[parsing_trees]

Also, there's an app for iphone called Corona that has a DLI and PPFD meter: ...

This guy on youtube runs a comparison to a real Lux meter, so it seems the app is pretty solid and will get you close for just a couple bucks. Note that you have to put a piece of white paper over the camera lens when using or the numbers will be all out of whack. I think the app actually makes note of that little hack now, but didn't when I first got it.

That's because smartphone sensor hardware fundamentally isn't set up properly for this use case. The light sensor on the phone doesn't have a translucent dome for cosine correction, so instead of measuring light coming from a range of angles, over a wider area, it's just measuring light hitting the tiny sensor straight on. It's like measuring brightness through a pinhole, when really what you want for growing is to measure how much light hits the leaf surface area. Putting white paper over the lens will definitely affect the readings, but it isn't likely to make them more accurate. They'll take your money either way, though.

You can get an actual lux meter for about $25. I find mine invaluable for finding spots in the canopy that are getting significantly more or less light than the rest, usually I can't tell just by looking.