Abstract: A telescopic optical system adapted to form an image of an object of interest which is only slightly angularly displaced in space from a bright object such as the sun. The optical system is pointed directly at the object of interest such that the geometrical image of the sun is not within its field of view. However, radiation from the sun is of such great intensity that radiation diffracted into the optical system may be many times greater than radiation forming the image of interest. In the preferred embodiment the image of interest is positioned beyond the hundredth diffraction ring of the sun. Undesired diffracted radiation is substantially reduced by apodizing the edge of the entrance aperture to the optical system to change the diffraction pattern of the solar radiation. In a first embodiment, the edge of the entrance aperture is apodized by placing a saw tooth pattern along selected edges of the aperture.