After spending a little more time on other threads, I realize that I am extremely lucky. Most of the other threads have had their pictures deleted during this last bit of site improvement. I'm just happy to get to keep mine, I guess.

Also I'm lucky that one of the things that disappeared I composed in MS Word, so I have a copy of it. I should say a copy of part of it, since after pasting it into the reply box I wrote a bunch of other stuff too. I aint going to go back and read everything and try to remember what I added, but here's a lot of it:

OK, why a stadium screen? Why any screen?

Itā??s all about light dispersal patterns of various bulbs, and using all available light as efficiently as possible. Several of us are only allowed to grow so many plants, so we want to utilize everything possible to get the highest yield we can from a small number of plants. Even those of us who arenā??t concerned about number of plants could greatly benefit from the use of a screen. It is more work to employ the use of a screen, there is no doubt. However, other than getting the basics correct, it is probably the single biggest thing a person could do to improve yield.

Imagine pointing a flashlight in a dark room. There is a circular or oval shape that the light is dispersed within, but other parts of the room are receiving light as well. Imagine growing with a flashlight. It wouldnā??t make any sense to put plants outside the range of that circle of light, even though light is present there. Also, within that circle, there are brighter areas than others. For most bulbs the most intense light is in the center of the circle or oval, and thatā??s what the plants would reach for.

If you are growing with fluorescent tubes in a reflector, the pattern of light dispersal is mostly straight down, anywhere under the reflector. There are still more intense places under the reflector, as is the nature of all lighting systems, some more than others. However, in general the light is coming down in a shape of a rectangle. If you put a flat screen under the rectangle, and make it in the same shape as the rectangle, you are able to more efficiently place buds so that more of them receive an equal and proper share of light. If you donā??t train at all, the plants just grow cattywampus, but mostly in the direction of the most intense light. There will be many places under the reflector that are not occupied with buds. It would be much more efficient to not let the light hit empty spaces, and instead fill in those spaces with buds.

Now what do you do with HID lighting, since the light dispersal pattern is not flat like a fluorescent tube? Imagine a grow under an HPS without a screen of any kind. 3 or 4 of the plants will be taller than the rest, there will be many spaces of light that are not filled with buds, and in general, the grow as a whole will resemble the shape of a Christmas tree, with the top center of the tree being the closest to the most intense area of light. In this case it happens to be right in the middle of the bulb, directly under the reflector. The couple three buds closest to that area will be some nice big ears of corn, but that is not necessarily what will give you the overall greatest yield. Now letā??s say you put a flat screen under the HID light. That would eliminate some of the problem of areas of light not being taken up with buds, but in general the grow will be in a shape of a Christmas tree again, not making efficient use of lighting. A person can compensate for this somewhat, by training the main colas to the outside and leaving the smallest colas toward the middle of the screen where the light is most intense. Since the light dispersal pattern of HID lighting under a reflector is in the shape of a ball, the ultimate use of space would be to have buds in a globe, or ball shape all around the edge of that light dispersal pattern. That way every bit of light coming from the bulb will be hitting buds, once they are properly placed. The next best thing would be to have a stadium style screen, which is a half-globe made out flat panels instead of concave ones, or one concave one. Another big advantage of a stadium screen is it will give you 10-15% more surface area than a flat screen. Kinda like the screen in this grow.

Now what is the light dispersal pattern of a CFL bulb? I donā??t know and I wish someone would tell me. I am guessing it is mostly in a ball like with HID. Who knows though? Does it come mostly out the end of the bulb or out the sides, or is it a nice even ball shape? Also, what about those massive CFL conglomerates, that have like 8 CFLs all branching off Y adapters? Itā??s probably like one bigger ball of light intensity, but I donā??t know. Again, Iā??m guessing. Only someone with a light meter will be able to tell.

I hope I havenā??t served to confuse you more. Is it perhaps just a little more clear as to why I like a screen in my grow? And why I like a stadium screen in my HID grow? As usual, Iā??m somewhat baked and donā??t know for sure if Iā??m making proper sense.