A method of enlarging an image field of a camera by combining partial images. This method includes continuously rotating at least two refractive prisms such that an optical axis of the at least two prisms scans in a cycloidal pattern. Furthermore the method includes capturing and combining a plurality of partial images. Finally, the cycloidal pattern is formed as an astroid pattern with a plurality of vertexes. The partial images are generated at the time of the reversal movement during the scanning in the astroid pattern, which limits unsharpness in the images kept to less than the size of a pixel.