Spectral lightmeter Gigahertz-Optik MSC15

ReddEyez said:

Great thread everybody! Thank you for all the testing and info. Great job Malocan, thank you for all your time! Your lights look great man!

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thank you very much

cdgmoney250 said:

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.

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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 said:

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.

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Photo Credits: @Greengenes707
Sorry for not asking

cdgmoney250 said:

Just think larger than a tent.

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Respectfully, all @Malocan's data shows is that average PPFD goes up with reflectors, and uniformity drops, at both 30cm and 60cm.

This has been a peaceful thread, sharing raw data without arguing about it. Let's keep it that way.

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.



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.

Malocan said:

Thank you very much salmonetin,
i will read it before i going sleep, my sleep lecture A lot of informations, intersting

Thanks

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....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...



Saludos

@Malocan - looking at the 730nm threads had me wanting to know what sunset looks like through your meter. Have you taken any sunlight measurements for noon to sunset? Sorry if you already have done this.

nevergoodenuf said:

@Malocan - looking at the 730nm threads had me wanting to know what sunset looks like through your meter. Have you taken any sunlight measurements for noon to sunset? Sorry if you already have done this.

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hi,
no i didnt shared stuff like that, i will make tomorrow some screenshot and will share them.
i hope i dont forgot.

Malocan said:

hi,
no i didnt shared stuff like that, i will make tomorrow some screenshot and will share them.
i hope i dont forgot.

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I'd like to see noon sun where you are too. It's surprisingly hard to google accurate sun stuff, I'm sure it's out there, but I haven't had a whole lot of luck. Great question @nevergoodenuf .

yeah good question, i wanted to do it often. but i forgot it always

JorgeGonzales said:

I'd like to see noon sun where you are too. It's surprisingly hard to google accurate sun stuff, I'm sure it's out there, but I haven't had a whole lot of luck. Great question @nevergoodenuf .

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found this

Daylight spectrum (a) versus sunset spectrum (b)

http://www.ledsmagazine.com/articles/print/volume-11/issue-5/features/agriculture/properties-of-led-light-can-boost-poultry-production-and-profits.html

wietefras said:

Nope, when you have a large room, reflectors are most definitely useless.

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or a tent!

BJBs are good like that, they catch that last little bit of light from 140-180 degrees and knock it down

here a measurement at morning time(07.42 / UTC+1), sun beginn to show up.
But moon is still visible, you can see it at the top of the photo



i will post later at day some other measurement

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

wietefras said:

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.

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Leeches are still used in medicine.

Tobacco is used to repel mosquitos.

So yes, both are still good for your health.

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

now i made a measurement out of the window of my sleeping room. Here we dont have see contact direct to sun, but the sky is clear.
See photo. 9.38 (UTC+1/morning time)

Almost balanced out

Malocan said:

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

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What's E_s in the last picture?

alesh said:

What's E_s in the last picture?

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fc maybe?