Commercial growers' height from canopy to light

Hey guys,

I have seen several commercial growers on the web & social networks who have lights raised pretty high. Easily 5-7 feet above canopy level. For example:

http://www.cannabisbusinesstimes.com/FileUploads/media/merryjane083116.jpg

This seems like it goes against the basic principle of putting lights close to canopy to give plants as much light as they can use. Anyone have any ideas how or why they are able to do this and still get good harvests?

When there is that much light in the room they dont need to be close. The closer they are to plants the more the plants stress.

Those also look like gavitas... best lights on the market Imo..

When you have a lot of lights in a room the overlap means you can raise them higher and still get the same amount of light per square foot as less lights at a lower height. It's also because with so many lights you don't want to be moving them up and down all the time.