3 Strain Run - Purple Opium, White Widow, Trumps Cookie Jar - Auto Fem

[MrE]

15 hours ago, Prom said:

Mhhhhhhh... People and their LUX/Lumens meters  If I remember correct, Veg you are more in the area of 30-40k Lux on the plant. All depends a bit what camera your phone uses.. you should aim for 500 micromole PAR light on the plant.. Lux includes green for example. PAR doesn't. If you got instructions with your light.. use those hanging distances. More accurate as a Lux meter, they measured the distances for the right PAR setup.

PAR does include green.

Wrt cellphones, some use the camera, some have dedicated sensors and some are now hybridised with another sensor. For Android, it's a shot in the dark as to whether it will scale reliably along a converted PAR reading from a quantum sensor.

Most newer iPhones with the correct grammage paper used as a diffuser, will provide very useable readings.

Wrt lux meters, it totally depends on the model, and if you're using the correct conversion rate. 

The guy from Migro has shown that the Uni-T ut383 scales reliably linearly wrt to the protracted, confirmed PAR readings from a scientifically accurate instrument. (However he has only provided the correct conversion rate for 3500K and maybe around 3250Kish)

Hey Prom, maybe you could use your SQ500 to check the accuracy of the apps on your particular phone model. If it's a popular model it could prove useful for some folks out there! 

 

At 28cm my phone was about 300 PAR off, 500 vs 800. (at that particular point)

Edited May 28, 2021 by MrE

[Prom]

9 hours ago, MrE said:

PAR does include green.

Plants reflect green light, and don't use it.. that is why you see them green 

[GGG]

The way I understand it is that PAR is the wave length of a light between say 400-700 and PPFD would be the intensity of the light that the plant receives ?

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[MrE]

3 hours ago, Prom said:

Plants reflect green light, and don't use it.. that is why you see them green 

Ok, I'm going to have to side with the scientists on this one. 8.33 timestamp.

 

Edited May 28, 2021 by MrE

[Prom]

2 hours ago, GGG said:

The way I understand it is that PAR is the wave length of a light between say 400-700 and PPFD would be the intensity of the light that the plant receives ?

Sent from my Hisense Infinity H50 using Tapatalk
 

That is the range over which the plants select the radiation they want to use... Green is part of that range, but not used by the plant for photosynthesis, they reflect that frequency. 

LUX/Lumens are units we use for our eye sight. The light for plants gets measured in PAR (Photosynthetically Active Radiation), what the plant can actually use. Green light on a LUX meter will give you a reading.. on a Quantum Flux meter you get hardly anything.  

[MrE]

27 minutes ago, Prom said:

That is the range over which the plants select the radiation they want to use... Green is part of that range, but not used by the plant for photosynthesis, they reflect that frequency. 

LUX/Lumens are units we use for our eye sight. The light for plants gets measured in PAR (Photosynthetically Active Radiation), what the plant can actually use. Green light on a LUX meter will give you a reading.. on a Quantum Flux meter you get hardly anything.  

"Sometimes one may hear that plants don’t use green light for photosynthesis, they reflect it. However, this is only partly true. While most plants reflect more green than any other in the visible spectrum, a relatively small percentage of green light is transmitted through or reflected by the leaves. The majority of green light is useful in photosynthesis. The relative quantum efficiency curve (Photo 1) shows how efficiently plants use wavelengths between 300 and 800 nm. Green light is the least efficiently used color of light in the visible spectrum."

https://www.canr.msu.edu/news/green_light_is_it_important_for_plant_growth

And 11:14 in this video.

"In a canopy, the green photons are still 90% captured"

Edited May 28, 2021 by MrE

[Prom]

24 minutes ago, MrE said:

"Sometimes one may hear that plants don’t use green light for photosynthesis, they reflect it. However, this is only partly true. While most plants reflect more green than any other in the visible spectrum, a relatively small percentage of green light is transmitted through or reflected by the leaves. The majority of green light is useful in photosynthesis. The relative quantum efficiency curve (Photo 1) shows how efficiently plants use wavelengths between 300 and 800 nm. Green light is the least efficiently used color of light in the visible spectrum."

https://www.canr.msu.edu/news/green_light_is_it_important_for_plant_growth

And 11:14 in this video.

 

Funny test.. would have loved to see what plants do under just green light.. They did it with Blue and Red.. as 100%.. not sure what they proved. At the end is a might.. not a clear.. it does.

The result of that report .. they used tomato plants.. would mean.. screw blue ^^ as hey.. pure red grows fastest even for seedlings?  Dang, why is my mother tent blue? What your Dr tells.. is in pure contrary of every grower I know.. including myself 

Only reason I use full spectrum light these days is because the diodes became more efficient and beside less stress on your eyes, you need white light to actually judge your plants health.. at least I do ^^ I grow very happy with a Blurple. But 100% red wins in germ, mentioned nothing for Veg.. they should have let the plants finish and not just post after Germination.. that is very weird for a result. Contradicts a bit all I learned from growing.

(Just read the article)

Edited May 28, 2021 by Prom
just read.. didn't watch the video

[MrE]

8 minutes ago, Prom said:

Funny test.. would have loved to see what plants do under just green light.. They did it with Blue and Red.. as 100%.. not sure what they proved. At the end is a might.. not a clear.. it does.

The result of that report .. they used tomato plants.. would mean.. screw blue ^^ as hey.. pure red grows fastest even for seedlings?  Dang, why is my mother tent blue? What your Dr tells.. is in pure contrary of every grower I know.. including myself 

Only reason I use full spectrum light these days is because the diodes became more efficient and beside less stress on your eyes, you need white light to actually judge your plants health.. at least I do ^^ I grow very happy with a Blurple. But 100% red wins in germ, mentioned nothing for Veg.. they should have let the plants finish and not just post after Germination.. that is very weird for a result. Contradicts a bit all I learned from growing.

(Just read the article)

Watch the videos regarding the science.

But you're right, that article wasn't the best example.

Green penetrates through to lower growth better than any other colour.

Shame we've taken over the thread though Can a mod move our conversation elsewhere?

Edited May 28, 2021 by MrE

[MrE]

3 hours ago, GGG said:

The way I understand it is that PAR is the wave length of a light between say 400-700 and PPFD would be the intensity of the light that the plant receives ?

Sent from my Hisense Infinity H50 using Tapatalk
 

PAR is measured in umol, that's the reading, and then PPFD is PAR divided by m² per second.

Super useful video.

[Prom]

1 hour ago, MrE said:

Ok, I'm going to have to side with the scientists on this one. 8.33 timestamp.

 

I have to watch the other one too? working though this one.. thanks for indicating the 8.33 mark, but penetration means just.. not absorbed by the leaf. I am kinda sure the good man understands that. Means, red and blue get very fast absorbed and USED by the plant.. that is why it disappears  green nearly goes through.. and the far red will disappear in flower material also faster... leaves don't need the far red in flower.. the flowers do

I enjoyed more timestamp 11.00 ^^ that is for the HID guys out there. I didn't thought LED is that much more efficient compared to HPS.

I grow trees without using green at all.. and I don't grow tomatoes ^^ more busy with crypto at the moment hehehe 

[MrE]

1 hour ago, Prom said:

I have to watch the other one too? working though this one.. thanks for indicating the 8.33 mark, but penetration means just.. not absorbed by the leaf. I am kinda sure the good man understands that. Means, red and blue get very fast absorbed and USED by the plant.. that is why it disappears  green nearly goes through.. and the far red will disappear in flower material also faster... leaves don't need the far red in flower.. the flowers do

I enjoyed more timestamp 11.00 ^^ that is for the HID guys out there. I didn't thought LED is that much more efficient compared to HPS.

I grow trees without using green at all.. and I don't grow tomatoes ^^ more busy with crypto at the moment hehehe 

You're confusing the Chlorophyll absorbtion chart with photosynthesis.

https://fluence.science/science-articles/do-plants-use-green-light/

"This article will discuss the differences between absorption spectrum and action spectrum, and (spoiler alert) dispel the myth that “plants don’t utilize green light” to promote plant growth and development."

Yes, HID hits about 1.35 on the efficiency chart(Useable PPF/Watt) at best, decent LED fixtures should be over 2.0. Currently the Chilled Growcraft Ultra 330W is highest at 2.68.

 

Edited May 28, 2021 by MrE

[GGG]

Bruce is a legend man , Apogee instruments also comes from him I am correct


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