When you look at a scenic mountain photo typically everything in the distance is in sharp focus. But this scene might be even more captivating if something striking were in the foreground, perhaps a field of wild flowers in peak bloom. The problem is if the flowers are close to the lens relative to the mountains it’s impossible for all elements in the photo to be in perfect focus — if the flowers are sharp, the distant mountains will be blurry and vice versa.
“This limitation is determined by the physics of optics,” explains Peter van Beek, a professor in the David R. Cheriton School of Computer Science. “The camera simply can’t take the picture you want, where everything is in focus, at least not in a single image.”