Photography lenses can easily be really expensive. So if you've got an awesome camera body lying around but no glass to go with it, you could always try and build a lens of your own like photographer and student Cormac Relf did.
DIYer Cormac built his lens out of a glass reading puck--which your grandparents might have lying around as a magnifying glass for reading tiny print--along with some construction paper and pieces of cardboard.
To start off his homemade lens, Cormac cut out a section of a cardboard tube and attached a cut-out paper aperture that sits in the camera body. For the lens portion, he rolled a strip of construction paper into a makeshift hood that the glass puck slips in to. Of course, you also have to black out the whole thing with some black marker to prevent light from leaking in and ruining your shots.
Taking photos with the DIY lens is a simple matter of holding the glass over the aperture housing and rotating the lens until your image is focused.
We don't know anything about the lens's focal length, but the images it produces mimic the soft, ethereal look of freelensing--because technically it is, as you actually have to hold the glass part in front of the camera while taking photos. Not bad for something that was just slapped together at home.