A Very Important Fact About Lighting For Your Plants
- Thread starter King Cobra
- Start date
Gastanker
Well-Known Member
Aside from misusing the term lumen you are quite wrong when it comes to CFLs and other florescent bulbs. Like I have stated before lumen do not stack for the simple reason that if you add lumen you end up with lux or candleft. You are essentially saying you want the area of a room but 3' x 3' equalling 9ft isn't the area - which of course it is not, it equals 9 sq ft which is essentially the difference between lumen and lux.
Now you are correct about penetration and that brighter single point sources of light 'throw' farther than multiple smaller sources of light due to the inverse square law even if the total amount of radiation is equal - however this doesn't translate to florescent bulbs except when comparing tube diameters and ballast types (normal, HO and VHO). You see fluorescent bulbs put out light over a large surface area and amount of light in similar bulbs is directly proportional to the length and diameter of the tube which holds the fluorescing gasses. Aside from minor changes in efficiency a 2' T8 is just as bright as a 4' T8 per inch of tube - so although the 4' T8 puts out more total radiation and covers a larger area it throws the light no further than the 2' bulb. This is where ballast type and bulb diameter come in - a 4' 38w T5 will not 'throw' as far as a 4' 52w HO T5 as the HO is actually putting out more radiation per inch of tube than the NO. Same thing when it comes to comparing T12, T8, and T5 to each other. It is VERY difficult to compare CFLs as they use varying tube diameters and lengths - for instance a 23w CFL is essentially a T5HO (T5 diameter with the power consumption over area similar to a HO ballast), a 42w CFL has a slightly larger diameter, a 68w CFL has a diameter more similar to a T8, a 250w CFL has 6 individual lamps which are more similar to 42w mini compacts (T4 HO equivalent I believe)... and these all differ between manufacturer as well
So again, a 250w CFL doesn't necessarily throw further than a 23w, 42w, 68w,... If a 23w CFL has a narrower diameter and shorter tube porportionate to the light it gives off than a 42w cfl, then the 23w cfl will actually throw farthur even though its labeled lumen is lower.
kpmarine
Well-Known Member
Okay, so going just by lumens for CFL. A 2700k, 200w cfl produces 12000 lumens, so that's a luminous efficacy of 60 lumens per watt. A 2700k, 26w cfl produces 1750 lumens, so thats 67 lumens per watt. So that means 200w of small cfl produces 1400 more lumens. With a bit of math (1400/12000=0.116), we can effectively determine that 200w of smaller bulb is 11.6% more efficient than a single 200w cfl.
Also, as an aside. If you don't understand what I said in the post about inverse square law (I assume you didn't, because all you took away from it was a lie that stated you could grow with flashlights.), feel free to ask for clarification. I'm really trying to help you understand why people are telling you that your premise is wrong, even with cfl's. The laws of physics don't stop being valid because your light source is a twisty tube instead of a HID.
Gastanker
Well-Known Member
Lumen is a great way of measuring the intensity of a single light (or fixture in some cases) in reference to how well it will provide illumination to an area for human purposes. Most lights are used for this purpose which is why that unit is used. They cannot use lux or ftcandles as both include a reference to area/distance and the manufacturer has no idea of the room/area you will be installing the light - they cannot predict where or how you will use it.
Gastanker
Well-Known Member
On whether we will ignore the laws of physics for the sake of a pot forum? I still believe physics over forums.
well ive forgotten wat the fuk this threads was even about so ther ya go
del66666
Well-Known Member
im no expert but yes i think this might be the case.........its a bit like having 1 bb gun against a 100 bb guns.............a hundred bb guns might do more damage than 1 but they still wont fire any greater distance
although ive never had a bb gun.......
PJ Diaz
Well-Known Member
..however if 100 bb guns are fired at the exact same point at the exact time, they will have 100 times more combined force.im no expert but yes i think this might be the case.........its a bit like having 1 bb gun against a 100 bb guns.............a hundred bb guns might do more damage than 1 but they still wont fire any greater distance
King Cobra
Active Member
That would be impossible! As you would have to hit the point at different angles from the same distance away! Therefore you would not be hitting the point in exactly the place, if that were the case then you may aswell get 100bb pellets and stick them together in a round ball and fire them through a super wide nozzeled bb gun.!! So the point here is if all the pellets were fired at the same point at the same time from the same distance, they would just hit each other when they get to the same point of contact. Thus resulting in the same force as if you only fired one!
fatality
Well-Known Member
you dont know what your talking about son, lumens don't add up, didnt the poster to this thread explain that? It is irritatiing talking to people who talk about throwing in another light the samsize and say they have more lumens.... depending on what brand 600 watt bulbs you have you are only going to have 80-95,000 lumens in any given spot under your two 600's..... the only cool thing that you change is your footprint of light when you have more lights, allowing you to grow more plants under the same equal intensity....... people really should take more time to read..
fatality
Well-Known Member
people put more lights into rooms because they want a bigger light footprint, not to up the lumens in the room, quit being a neanderthal and open a book or webpage and devote at least 2 hours to studying light and light output, maybe the lightbulb will still be able to go off in your head anyou can realize a thing or two
Gastanker
Well-Known Member
You obviously have not taken your own advise - radiation stacks (all types). How about we just have everyone take the time to attend a class. Here's UC Berkeley's Lecture series on physics. I would suggest that those of us not familiar with physics to start at lecture 11 (waves). Actually if you are unfamiliar with physics you might want to start at lecture 1
[video=youtube;Z0exIzsKuq8]http://www.youtube.com/watch?v=Z0exIzsKuq8[/video]
fatality
Well-Known Member
with the same types of bulbs running your lumen output will be the same no matter how many you have running, your FOOTPRINT in which to grow will be increased, that is all peeps need to know, also i am not condoning one light, because the more lights you have the more saturation you will get, but that is not talking intensity
PMSL now wer onto bb guns ,.,,,from lighting,,now even i know comparing the 2 is a stretch
Gastanker
Well-Known Member
Not sure how many times this needs to be addressed but plants DO NOT use lumen. Plants use electro magnetic radiation to perform photosynthesis. EMR adds. If you have one bulb putting off x # of photons and another bulb putting off x # of photons then together they put off 2x # of photons. If all of the photons are making contact with the plant then with 2 bulbs the plant will be receiveing twice the amount of energy.
Get over the term 'lumen'. You obviously have very little knowledge when it comes to light if you are trying to add lumen.
I have a 500hp ferrari that can go 200mph. I weld my ferrari to another ferrari. Can it go 400mph now? No... together can they pull twice as much? Yes...
ThE sAtIvA hIgH
Well-Known Member
the op is absolutely right .
PJ Diaz
Well-Known Member
Obviously you've never taken physics. Obviously you have never grown. Obviously you don't know more than lighting designers and physics professors.
