Hi, I've owned an Optoma DX319 (2500 lumens) for a couple of years now, it only gets used at a Presentation Evening and it's great, I always panic about the projector breaking and have been on the look out for another as a back-up, anyway I came across a Vivitek D-945VX and managed to get it at a good price, it's used 1177 hours of its 2000 hours. It's rated at 4500 lumens so I expected it to be brighter than the Optoma but it's not, if anything it's dimmer. Do you think a new lamp will fix the problem ?? Everything else seems okay with the display apart from the brightness.