Using a disc as a lens
An amazing diffractive effect: A simple disc can form a high resolution image with very high magnification – No lens required.
We demonstrated the performance of an Aragoscope using a 2.5″ hard disc as a lens. The resolution is comparable to the limit of what can be created with an aperture of this size.
We imaged 25mm and 50mm high stencil target images from 200m away corresponding to the angular size of Mars (26 arcseconds) and Jupiter (52 arcseconds) respectively. Despite stray light we got a good amount of detail, comparable to a telescope with a 2.5″ aperture:
The Aragoscope uses the diffraction of light around a circular edge to form an image on a plate some distance behind the disc.