|
 Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
|
 Hawksresurrection
Registered: 12/04/08
Posts: 13,464
|
 Re: lighting question  [Re: double]
#610299 - 02/23/12 09:29 AM (12 years, 9 months ago) |
|
|
Oh I think it will be just fine to grow it along side. No issues there man.
--------------------
Dude she isn't as young as she use to be.
-niteowl
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
|
So does proper-wavelength make the difference over regular lights which give off a lot of heat?
Can plants known to be half-shade lovers be grown along with full sun lovers? 
|
Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal 
|
Re: lighting question [Re: double]
#610302 - 02/23/12 09:33 AM (12 years, 9 months ago) |
|
|
Heat is a wavelength of light. IR and Far-IR.
--------------------
|
Hawksresurrection
Registered: 12/04/08
Posts: 13,464
|
Re: lighting question [Re: double]
#610304 - 02/23/12 09:35 AM (12 years, 9 months ago) |
|
|
In a setting like LEDS they will do just fine. And I'm not really sure about the shade loving question. But if you just set it off to the side it will probably be just fine.
--------------------
Dude she isn't as young as she use to be.
-niteowl
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
|
I meant that some plants thrive in full sun while other are adapted to shaded locations. But yeah I got your point of having them get some side/reflected light instead of centering them, thank you
|
Hawksresurrection
Registered: 12/04/08
Posts: 13,464
|
Re: lighting question [Re: double]
#610307 - 02/23/12 09:41 AM (12 years, 9 months ago) |
|
|
Yup yup.
--------------------
Dude she isn't as young as she use to be.
-niteowl
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
|
 @ you both.
I'm puzzled by reading that blue light mainly helps vegging and seeing led lamps made of mostly red lights, in a 1:6 ratio or something like that.
since leds do poor at flowering (which to my knownledge requires red and far-red wavelengths, along with UVB for increasing resin production) while they're sufficient for vegging, why not just make lights made up of only blue leds?
|
Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
|
Re: lighting question [Re: double]
#610309 - 02/23/12 09:52 AM (12 years, 9 months ago) |
|
|
The reason plants prefer a blue spectrum for vegging and red-shifted light for flowering is an evolutionary by-product. During the spring time (in the northern hemisphere) the planet is literally moving towards the sun, which by way of the Doppler Effect "compresses" the electromagnetic waves emitted by the sun and causes all the light to shift slightly more towards the blue spectrum. At the summer solstice (which is coincidentally the moment that the days start getting shorter as well) the earth passes it's closest point and begins to move away from the sun again. Once again, Doppler Effect, or Red-Shift, takes over and "stretch" the light ever so slightly towards the longer wavelengths.
Plants only "prefer" those wavelengths because they're used to them from thousands of years of evolution. You can mess with it and not be very detrimental in my experience. I've flowered with blue bulbs and gotten great results, and I've vegged under HPS without any issues as well.
--------------------
|
Hawksresurrection
Registered: 12/04/08
Posts: 13,464
|
|
I grow with HPS through my whole grow. Mainly because I'm lazy and don't want to have to remove the glass and switch the bulbs etc.
But I get great results with that.
--------------------
Dude she isn't as young as she use to be.
-niteowl
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
|
Quote:
Harry_Ba11sach said:
The reason plants prefer a blue spectrum for vegging and red-shifted light for flowering is an evolutionary by-product. During the spring time (in the northern hemisphere) the planet is literally moving towards the sun, which by way of the Doppler Effect "compresses" the electromagnetic waves emitted by the sun and causes all the light to shift slightly more towards the blue spectrum. At the summer solstice (which is coincidentally the moment that the days start getting shorter as well) the earth passes it's closest point and begins to move away from the sun again. Once again, Doppler Effect, or Red-Shift, takes over and "stretch" the light ever so slightly towards the longer wavelengths.
Plants only "prefer" those wavelengths because they're used to them from thousands of years of evolution. You can mess with it and not be very detrimental in my experience. I've flowered with blue bulbs and gotten great results, and I've vegged under HPS without any issues as well.
So would, watt for watt, be more efficient red 660nm or blue 460nm light? Since leds perform acceptably only at vegging, one may go with using only one wavalength instead of two, if this makes an efficiency difference for the current used
I'd hate to use a commercial red/blue 6:1 and get poorer results than getting a completely blue led panel.
Thank you
|
Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
|
Re: lighting question [Re: double]
#610319 - 02/23/12 11:37 AM (12 years, 9 months ago) |
|
|
The MOST effective light would be hitting every single peak on this graph, at respective intensities to the size of the peak. 
only ONE wavelength is never going to be the best. Plants need a blend because there are multiple photosynthetic pigments.
--------------------
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
|
Thanks for your reply, that's the kind of answer I was expecting
By looking at the graph I also see how using only the highest peaks (660 and 460nm) wavelengths light makers make a compromise on efficiency/cost
Only reason I can guess by logic on such a big difference in red/blue as seen in lights using a 6:1 ratio is that plants have way less chlorophyll a than chlorophyll b 
Thanks again
|
 bm90191
New To Growery
Registered: 02/05/12
Posts: 155
Last seen: 11 years, 1 month
|
|
Quote:
Harry_Ba11sach said:
The reason plants prefer a blue spectrum for vegging and red-shifted light for flowering is an evolutionary by-product. During the spring time (in the northern hemisphere) the planet is literally moving towards the sun, which by way of the Doppler Effect "compresses" the electromagnetic waves emitted by the sun and causes all the light to shift slightly more towards the blue spectrum. At the summer solstice (which is coincidentally the moment that the days start getting shorter as well) the earth passes it's closest point and begins to move away from the sun again. Once again, Doppler Effect, or Red-Shift, takes over and "stretch" the light ever so slightly towards the longer wavelengths.
Plants only "prefer" those wavelengths because they're used to them from thousands of years of evolution. You can mess with it and not be very detrimental in my experience. I've flowered with blue bulbs and gotten great results, and I've vegged under HPS without any issues as well.
Yup learned about this in astronomy, the wavelength of the suns light is blue shifted as we are moving towards the sun in the summer months and red-shifted when we're moving away from the sun in the fall. I didn't even think of that harry, I thought it had more to do with Earth's tilt on it's axis which, as we all know, is what causes season changes. I never thought that doppler effect we learned about in astro for gaging distance and directions of stars applied to how cannabis plants respond to the sunslight..thats super interesting guess you learn something new every day! lol
|
Hawksresurrection
Registered: 12/04/08
Posts: 13,464
|
Re: lighting question [Re: bm90191]
#610357 - 02/23/12 05:38 PM (12 years, 9 months ago) |
|
|
I thought it was the axis as well. But I haven't really taken any classes on this subject.
--------------------
Dude she isn't as young as she use to be.
-niteowl
|
Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
|
|
The axial tilt influences the intensity of the sunlight hitting the surface and therefore how much energy is absorbed and reradiated as heat into the atmosphere (causing the seasons). It doesn't affect the wavelength shift of incident light.
--------------------
|
bm90191
New To Growery
Registered: 02/05/12
Posts: 155
Last seen: 11 years, 1 month
|
|
Yeah its confusing because the northern hemisphere is actually closer to the sun in the fall/winter but like harry said its the doppler effect that has caused cannabis to evolve in accordance with the blue and red shifts
|
Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
|
Re: lighting question [Re: bm90191]
#610373 - 02/23/12 06:39 PM (12 years, 9 months ago) |
|
|
Quote:
bm90191 said:
Yeah its confusing because the northern hemisphere is actually closer to the sun in the fall/winter but like harry said its the doppler effect that has caused cannabis to evolve in accordance with the blue and red shifts
Only in the southern hemisphere.
In the northern hemisphere then our axial tilt aligns with the solstice movement shifts. ie, in the winter when we're tilted away we're also at our farthest point. In the summer when we're pointed towards it is our closest point.
--------------------
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
|
would placing plants close to LED lights emitting red/blue wavelengths ever produce burns or issues?
I am asking since they don't emit anything else other than their wavelengths and some heat (which goes up and is taken care of, though) due to joule effect, so virtually no IR radiation could the plants.
|
Stoneth
D.I.L.L.I.G.A.F.
Registered: 10/06/08
Posts: 25,048
Loc: No where ville, USA
|
Re: lighting question [Re: double]
#616475 - 04/05/12 09:58 PM (12 years, 7 months ago) |
|
|
I've seen sunburn and even bleaching as a result of running the lights to close to the canopy.
--------------------
|
double
Diesel
Registered: 02/12/11
Posts: 207
|
Re: lighting question [Re: Stoneth]
#616500 - 04/06/12 04:34 AM (12 years, 7 months ago) |
|
|
Quote:
Stoneth said:
I've seen sunburn and even bleaching as a result of running the lights to close to the canopy.
are you talking about LED lights emitting no UV or IR?
|
|
Threaded
Previous
Index
Next
Edit 
Reply 
