Need more information.
It depends on optics/reflector type of the fixture and lens as well.
Also, lumen is light rating of a specific source. Lumens have a very small affect on what you are referring too. I believe what you want is a set fc within an area.
A) what is the purpose of the light? (what are you doing under the light)
B) what area do you want this to cover?
C) is this your only light source.
In short, you are going about lighting up an area backwards. You need to start with what you have/purpose of lighting and then look at what will best suit that.
EDIT: I would never advise using an MH250 setup for a mounting height of only 8'.
