Hoovercam - Large Format the cheap way

I have built a large format camera out of a cardboard box as a means to assess coverage of some lenses I had bought. The resulting images are better than I expected.

The use of RC paper in the place of film and the making of contact prints form it works surprisingly well.

The camera, made of a vacuum cleaner cardboard box

The film holder

Inside the box an easel made of cardboard holds the paper. A piece of ground glass is taped to the easel for focusing. (Transparent paper would do)

Focusing

The image is focused on the ground glass. The easel position is marked with felt-pen.
Then the negative "film"-paper is taped (under safelight) to the easel and the easel is taped to the marked position.
Due to the mechanical tolerances it is recommended to stop the lens down to at least f/32.

Resulting images:

The resulting negative is very detailed if the lens is focused correctly. As most RC papers have almost no fiber structure the negative can be contact printed to yield a positive image.