If grow space is an issue, vertical makes sense. This was more or less the conclusion i reached. Yeah, related also, one is limited in the coverage available with a vertical bulb position, there is no inverse square relationship. 600w+ lights have such great intensity that a canopy isn't as much an issue, as well this is half the point of larger wattage lights. As, i think at that point, anything above 400w you almost defeat the purpose. With a vertical grow there is no canopy, so no issues of light penetration. all the astonishing vertical grows i've seen where of the lower end of the intensity scale of lights. I think there is a relationship with vertical growing and choice of light source. Yeah, thats pretty much inline with my thinking. Also, i DO realize these are approximations, but i am merely giving a physical form to an idea, and at least in some form this here represents reality. then i realized my own conclusions and what i had saw personally, using low intensity, vertical, multiple light sources and how that turned out better than any single large source.

I thought all i had realized was a fallacy, well, of coarse a larger single more intense source is more beneficial. In typing this, i was considering how this plays out. i've produce buds from multiple, very elongated 36w sources, that looked like it came from a 400w+ HID, all because of ratios of light:grow space and light lant proximity and plant:emission sources. So, while only a 1/4 of the bulb is being utilized at a time, the distance to said source from plant can be much closer. As well, i know all to well the benefits of light to grow space ratio and multiple points of light vs one large one, as well as proximity of plants to light source. Granted with a vertical situation, there also is little to no canopy so penetration is not even a consideration. so in effect you are getting 4 100w sources of light vs one 300w source, with the same 400w bulb. With a vertical bulb there are no reflective losses, but, the bulb is then cut into 4 sections.

So this is where i'm trying to consider how this works with a vertical bulb. However, there is this consideration in a horizontal orientation, all that energy is being diverted to one place, straight down, all in one area. Therefore a horizontal bulb is more like 300w instead of 400w. so you are in a sense getting 120 watts coming back down towards the plants because of the loss from reflection. So that puts the downward portion of the bulb producing 200w and the upper portion producing 200w. moreso in a horizontally oriented bulb, might be better to put it into two quadrants. However, a bulb produces 360 degrees of light, but for simplicity we'll put that into quadrants of either 4 or 2 depending on light orientation. In a typical situation, you have a light or lights over top an area with a reflector shining down, you loose like what is it 30% efficiency with a reflector? so 30% of 400 is 120.

Vertical grow light reflector