Turn an old telelens and a webcam into a powerfull telescope that is capable of seeing craters on the moon. Next to the webcam and tele lens all you need are some standard pvc plumbing materials (pipes, diameter adapters and endcaps)
1. A webcam (I used a quickcam 4000 from logitech I still had)
2. A telelens, the more focal length the more magnification you'll get, the lens I'm using here is 80-210mm, you can get them at ebay starting from 12dollars. Many people have old tele lenses left from the analog camera era so there are plenty of them on the web.
3. Some standard pvc plumbing materials: pvc pipes, a diameter adapter to fit different diameters and some end caps. What you need precisely depends on your lens. More details on this can be seen on the next steps.
4. It's not part of the telescope itself, but it is important to have a tripod since the magnification is very large so any movement will ge greatly magnified. So without a tripod as a stable base, you won't be able to use your telescope.