Spectral lightmeter Gigahertz-Optik MSC15

wietefras

Well-Known Member
Testing spread without reflective walls would be beneficial for anybody with a larger size grow. Large canopies don't have the luxury of having much/any wall reflectivity.

Reflectivity will skew stand alone results.
Just think larger than a tent.
Nope, when you have a large room, reflectors are most definitely useless. At 30cm above the canopy, the COBs have a spread of around a meter. So a COB more than 50 cm away from the wall should never have a reflector. The bit of light that falls outside the beam angle will bounce back just as well on the wall instead of a reflector. As shown by Malocan. Even with a less than optimal reflective surface.

Besides, if you would want to measure the footprint of a COB for a large grow room, you should include all the light and not just the portion of light in the center. Preferably a COB should then be placed in the middle of a 4'x4' area and then measure the whole surface like Malocan did.

Either way, this is no longer a theoretical discussion. You can clearly see in Malocan's data that over the whole surface the bare COBs end up with 20% more light on the plants. Therefore, smaller or bigger room won't make a difference. Reflectors clearly always lose a lot of light.

Reflectors only make a tiny bit of sense when you insist on hanging the COBs higher than needed above the plants or if you insist on not having walls at all. Even then only on the outer COBs and only if you replace the reflectors every grow or maybe every two grows.
 

wietefras

Well-Known Member
Malocan shows clearly that bare COBs give 20% more light over the growing area (apart form at the open door). Yet some people still doubt this? Just ... wow.

Light_loss_from_reflectors.png

Do you still think leeches are of great use in medicine? That cigarettes are good for your health? Because people mistakenly believed those things too at some point.
 

salmonetin

Well-Known Member
Thank you very much salmonetin:hug:,
i will read it before i going sleep, my sleep lecture:sleep: A lot of informations, intersting

Thanks :peace:
....other good pdf reading on light measurements....from LI-COR web... ...clic on pic...


Principles of Radiation Measurement


...i like this other too... ...clic on pic for pdf...


Light Measurement Brochure


...and a lot of info on Apogee web.. on her large and awesome knowledge base... and a lot of good vids on her youtube page too...

http://www.apogeeinstruments.com/knowledge-base/

...i hope you like.....yeah lot of things to read or view... but hey its free... you can watch or read when you like or can... Thanks a lot to Authors...:hump::clap:

:peace:

Saludos
 
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ya bongo

Well-Known Member

PhotonFUD

Well-Known Member
Nice!

I would hazard to guess that the high blue weighting is due to most of the light being received by the sensor is coming from the blue sky overhead just based on the picture.

At sunset and sunrise on the horizon it should start in the red region and move quickly across and fill up the green then blue regions. Around 11am-1pm you should see it max out and be fairly balanced at all wavelengths but that may be affected but environmental factors so don't hold me to it ;)
 

PhotonFUD

Well-Known Member
Malocan shows clearly that bare COBs give 20% more light over the growing area (apart form at the open door). Yet some people still doubt this? Just ... wow.

View attachment 3762944

Do you still think leeches are of great use in medicine? That cigarettes are good for your health? Because people mistakenly believed those things too at some point.

Leeches are still used in medicine.

Tobacco is used to repel mosquitos.

So yes, both are still good for your health.
 

Malocan

Well-Known Member
now its 9.23 (UTC+1/morning time), on my balcon the sun shine pretty bright allready for this time.

Measurement was taken on my balcon, sun side of home. Sun shine directly on my balcon like you can see on photo
 

Attachments

alesh

Well-Known Member
now its 9.23 (UTC+1/morning time), on my balcon the sun shine pretty bright allready for this time.

Measurement was taken on my balcon, sun side of home. Sun shine directly on my balcon like you can see on photo
What's E_s in the last picture?
 
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