Light distance and power with a 205W Sanlight LED

i'd raise it a bit rather than dimming. the cost difference is minimal in this context and more photons bouncing around will potentially hit lower areas better, i'd assume. other factors are relveant too.. a bit more warmth (to a point) can help mitigate extra light. A little more RH to offset any excess evaporation (see "VPD" vaper pressure deficit). or add some co2 and control temps/rh etc... so, yo may find you still need to adjust an inch or 3 even after you map this out for future reference. it's all relative... so, if you find a max dLI over 18 hours, it'll handle the same DLI in bloom over 12 hours == 150% more intense light over 12 hours on canopy one way or another. (along with vpd, good about daily light integral too - DLI) inverse square law applies when increasing height. if you double the distance, it is 1/4 of previous intensity. it spreads out quickly in all directions every inch added. it usually won;t take a large adjustment unless something incredibly bad is going wrong.