Big photos of little coins allow detailed measurement of small features in the tool and die market

摘要

When Martin John Callanan of the Slade School of Fine Art at University College London contacted the National Physical Laboratory (NPL), he wanted to put together an exhibition featuring large images of the lowest denomination coins from around the world. Petra Mildeova, from NPL's Advanced Engineered Materials Group, demonstrated that full- colour images could be taken using an Alicona InfiniteFocus 3D optical microscope. Five coins were imaged containing over 400 megapixels, allowing coins of less than 20 mm in diameter to be printed as 1.2 m-diameter images. The images were described by Martin John Callanan as "really stunning" and he has exhibited them in Spain and Germany.