Iris Shadow
A collimated green laser and an iris generate a shadow. From a far distance, light seems to create sharp edges, but from a closed distance these sharp edges blur. In the background, the light exposes the imperfections of the wall's white paint, looking like speckle. The light corresponds to a solid-state green laser, spatially filtered and collimated. The image was taken with the camera of a Samsung S9. The image was taken at Universidad de Antioquia, in a laboratory of the Optics and Photonics Group (GOF).
—Edgar Rueda, Universidad de Antioquia, Envigado, Colombia