"Okay so imagine you're in a dark room with a hole the size of the punchhole behind you. The light would bounce off the top of the bridge and go through the hole all the way to the floor of the room and light will bounce off the grass and go through the hole all the way to the top of the ceiling. You'll be seeing the bridge upside down and back to front," she said.
Ms Stoppard said she hoped the obscura would be a chance to combine old technology and new technology.
"So we want to put a webcam inside facing the [projection] that links to a website so 24/7 you can see the bridge online. We also want to have an area where people can stand outside, in front of the hole, and go on their phones to the website and be able to see themselves upside down," she said.
Ms Stoppard said the design of the camera obscura would have to be striking.
"We want to use the art of Trish Clarke to the exterior of the sculpture - she does this brilliant work using laser work to create patterns and silhouettes. It'd have to be something that looked amazing or nothing at all," she said.
Ms Stoppard said the project was in early stages but so far she'd received "great" feedback from the council and had a meeting next week with them to further discuss the project.
"We can't build on their land without their permission. We're not asking for funding. Once we know what we can do, we'll look into designs and costs for the project," she said.