Jacob Metius else from claiming them. In October 1608, the States General discussed Jacob Metius's patent application for a device for "seeing faraway things as though nearby," consisting of a convex and concave lens in a tube, and the combination magnified three or four times. His use of a convex objective lens and concave eyepiece may have been a superior design to Hans Lippershey telescope design which was submitted for patent only a few weeks before Metius'. Metius informed the States General that he was familiar with the secrets of glassmaking, and that he could make an even better telescope with the
Focal cloud Focal cloud A focal cloud is the collection of focal points of an "imperfect" lens or parabolic reflector whether optical, electrostatic or electromagnetic. This includes parabolic antennas and lens-type reflective antennas of all kinds. The effect is analogous to the circle of confusion in photography. In a perfect lens or parabolic reflector, rays parallel to the device's axis striking the lens or reflector all pass through a single point, the focal point. In an imperfectly constructed lens or reflector, rays passing through different parts of the element do not converge to a single point but have different focal points. The