I have a Sony Cybershoot DSC-150P. It's ok for unzoomed photos but as soon as I zoom-in and take a landscape photo there are marks clearly on the photos (sse photo). It must be dirt on the inside of the camera, which is annoying. I don't keep it in a case but I would have expected it to be ok since the lens withdraws into the body of the camera and a shutter comes across. My question is - Can I fix the problem myself or would I need to get a profesional to do it. The worst case is I just live with the problem only zoom post production. Cheers.