since you are spreading the light a little over a 2 foot span, i had to also on mine, i am thinking with the bulbs perpendicular to the front of the canopy. i had to put mine parrallel and you can tell where the coverage is waining. you may also want to spread the reflectors out a little to help. unfortunately, there may be some trial and error involved here, but this is where i would start. i have also found that you can cheat a little on the far edges. having a darker area on the far edges is not as noticable as if it were between the lights. as long as all of your LR is lighted.