Questions about new MH lighting

Hello everyone...   I just purchased a 175W MH Pendant...   Cheers....   It
is for a 55 gallon (48x12x18) tank.  When I hooked it up and hand-held it
over the tank, I was less than impressed with it.  It seemed to only light
the center of the tank and none of the sides.  Is this common or am I doing
something wrong.  It also didn't seem as bright as my former 80w of FLs.  I
heard that the MH is much more of an intense spotlight, while the FLs are
more of a 'coverage' light.  Does anyone else have any experience with this?
 Just for note:  my entire bedroom is lite up by the MH now, and I'm thinking
about building a 'fence' around the top of the tank to shield the rest of the
room and make looking at the tank bareable, is this feasible?  

     - Keith  Breedofish at aol_com