Technical specification projection system dlp projection method ceiling front rear 3d compatibility dlp 3d video compatibility edtv hdtv ntsc pal sdtv secam computer compatibility mac windows projection lens lens type manual focus manual zoom minimum lens aperture f251 maximum lens aperture f269 minimum focal length 2195mm maximum focal length 2418mm minimum diagonal image size 58420mm maximum diagonal image size 762m minimum projection distance 1m maximum project