Thanks for the answers. @xrok1: these are 2D images. Exported from SketchUp. So it's a SketchUp problem. But I think i've found the problem. I had made a scene before i tried the thing with the parallel projection. And I think that scene was set to perspective. so I think I must have klicked onto my scene and the parallel procection disappeared again... But I didn't notice that it dissappeared again. Problem solved. Thanks for helping. Timo77