That chart is a little misleading in that there is nothing indicating at what point the light needs to be air cooled. I don't care what strain you are growing, unless you're growing in a freezer to control temps there is no way you're going to have a 1000W light 10 inches above a plant without damaging the plant unless the light itself is air cooled.
The numbers I gave in an earlier post is based on non air cooled lights by the way.
I couldn't agree more. I passed that along as a guideline and assumed that it was based on light intensity without considering temps and growing environment. (like open air in a room vs a cabinet or tent)
Myself I use a 400 watt hps in a homemade cooltube, with a few cfl's in the corners of the cab. When moving lights around and adjusting distance, I use my hand to judge temps between a light source and the closest vegetation. If my hand gets uncomfortable in a minute, I know the plant will too.
I think the value in that chart is a guideline for intensity, and then tweak distances from there based on cooling, size of area, ambient temps, etc. It's easy to miss but at the top of those charts is a statement that says 'this chart is in reference to the amount of light, not heat. Just noticed that...
Happy growing!