Footprint Of Bulbs?

Is there a difference in the area covered by a bulb depending on if its 400w, 600w, 1000w, ect. does MH or HPS make a difference? Is there a general rule of thumb to go by or is just the intensity of light that changes?

i know that in the 150w its 2x2 the 250w its 3x3 and 400 its 4x4 i guess you could do the math on up. it would also depend on your hood but these are for a standard 4 sided hood

The footprint widens as the bulb and reflector become further away from the floor.

400w - 3x3' @ 12 inches from canopy

600w - 4x4' @ 18 inches from canopy

1000w - 5x5 @ 24 inches from canopy

Those are usually the standards for growing with an HID.

ok coo.. thanks for the help guys