Justin if you are talking about my experience 8 months. When my SPS crashed I checked everything and when everything checked out OK I checked lighting and found thoses results. And I know a light meter is not a par meter but over 50% drop in lighting output I would think would be proportional to 50% drop in PAR output. Since DE is smaller than SE you would naturally have a more dense light in a smaller area, kind of like a flood light versus spot light effect(probably not a very comparison but hopefully you get the idea)