yes I have. We already published some articles I wrote and there is a good paper on how to position lighting, though that is specifically written for our fixtures and reflectors. In general though, for any horizontal lamp fixture, the spread is not square and not a 4x4 or a 5x5 like many think it is.
Here you will find the papers and the articles (more to come soon): http://www.gavita.com/retail/gavita-lighting-academy/whitepapers-publications
Oh, and of course our YouTube channel. Gavita - YouTube
However, I believe that should be part of a separate discussion. Maybe a moderator can split these two posts to a separate topic about Lighting Basics. This is not a response to my response.