My institution's equivalent was projecting an image of a "criminal" behind bars, doing the masking with a piece of blue-tak in the reciprocal space, and then wa

My institution's equivalent was projecting an image of a "criminal" behind bars, doing the masking with a piece of blue-tak in the reciprocal space, and then watching the bars vanish in the image. And then doing the same thing with a cold-war era real life spy-plane photograph of the ocean, followed by masking out the frequency corresponding to the waves, and revealing the underwater submarine. Fun and lifelong memorable.