What's good about light movers?

[coolx]

I've read about light movers, but I just can't get what's good about them and I've read in some posts that they even decrease the yield. I've done 2 grows and I've used them both times so I've nothing to compare.

I'd love to get some comments as I see 2 problems:

Say the light moves down a foot or two, then the plants directly underneath the bulb are getting more light, BUT the plants at the other end are getting less light. IE what one hand gives, the other takes away. So at each end of the grow, the plants get 6 hours of good light and 6 hours of, say, half light.

So the question is: Is it better to have the ends of the grow get varying amounts of light like this than having the whole grow getting the average amount of light available the whole time?

OK, the other supposed advantage is that you can move the lights closer, cos they're not directly overhead all day and won't burn the plants.. BUT, and this applies to all calculations about bringing lights closer .....

Supposedly, light intensity is inversely proportional to the square of the distance away (well, yes it is), so a light 2 feet away has 1/4 the light intensity of a light 1 foot away. Now this is true, BUT what I have never heard addressed is the following:

The light comes off of the bulb in a cone shape, from around 40-60 deg angle (well when using a reflector of course). What this means is the area covered by the light is directly proportional to the square of the distance away, so a light 2 feet away covers 4 times the area of a light 1 foot away.

Sound familiar?!! Exactly, this totally cancels out the gains in bringing a light closer. A light has only so much energy to give after all. The only difference is in any light reflected off the walls. (Actually, not that I'm recommending this as the buds at the edges would be too airy, technically it's most energy efficient to have the light as far away as possible so as to have NO light reflected off the wall, so all light is directly used by the plants.)

The only thing that I see better about a mover is that the light comes in at varying angles, minimizing the number of budsites and leaves that could be always shaded.

 

[2buds]

I use a mover due to insufficient power to run 2 lights at once but my room is 4'x9' so the mover gets sufficient light to the ends while things like an a/c and blowers still have enough juice to work. If I had enough amps I'd rather run 2 lights but it also helps with the power bill, 1k an hour instead of 2k an hour and the mover uses around 15 watts.

 

[pico11653]

I have a mover and didn't like it for my flower room. The motor broke, but if it still worked I would use it in my veg room.

 

[Guest]

"The only thing that I see better about a mover is that the light comes in at varying angles, minimizing the number of budsites and leaves that could be always shaded."

exactly. light movers give you a denser canopy. remeber, you want a horizontal 'slab' of small buds instead of a few tall-standing ones (if you're growing for yield).

 

[2buds]

I will say my understanding of a light mover is that it doesn't increase the area a light is rated for but merely moves the light to varying angles to allow better penetration into otherwise shaded areas as stated above. For me, I'm using what works for my situation and I don't say its rite but it works. :smile: