Distance from Plant (basking) to Light?

[AZJ0SH]

How far away should the heat lamp be from the highest basking point on the plant? I am setting up my enclosure, and I have about 8" of distance from the very tip of the plant to my heat light, it's sitting at about 90 degrees in that spto (warm enough).

 

[Grim Crow]

I think most people here say between 6 to 10 inches, and ensure basking spot is within 10 inches of uvb light as well.