Patent ID: 7791797

Claim:
A filter for use in an optical system comprising: an electronic photographic imaging sensor for imaging an on-axis image of an on-axis object and an off-axis image of an off-axis object, the optical system having one or more first optical elements and an optically opposed and physically remote focal plane end; the filter being one of the first optical elements; an inner portion of the filter passing the on-axis image, an outer portion of the filter for attenuating the off-axis image of the off-axis object, the off-axis image of the off-axis object being a peripheral image passing through the filter's outer portion, the filter's outer portion having a nonidentical attenuation profile along points along any radial line extending from a center in the inner portion of the filter and through the filter's outer portion, the off-axis image and the on-axis image being imaged concurrently by the optical system, the off-axis image being incompletely blocked when passing through a selected portion of the filter's outer portion, and information sufficient to reproduce a photograph of the on-axis image being available from the imaging sensor.