MH Light Positioning

[Anonymous]

I notice that MH lights are mounted parallel to the length of a tank. Is the light spread widest perpendicular to the bulb or parallel? Since my wording may be confusing, will bulbs mounted like this have a wider beam front to back and narrower side to side?
I'm asking because I'm mounting 3 250W MHs above a 6 foot tank (18" wide) and wondered which configuration would give me the best light coverage.

 

[Anonymous]

It's a point source. Chew on that with your jointed oral appendages.

 

[JKDMan]

i think that it prolly depends on your reflector

if the bulb wasnt obscured by anthing the lighting would be equal 360 degrees
all around the bulb
i have 3 250 w mh on a 6ft long tank and they are running parallel to the direction of the tank