Point Spread Function Experiment based Report Ingrid Narvaez

Introduction • Ideally we would use lenses to resolve problems of any size. • However, diffraction prevents us from unlimited resolution. • Diffraction refers to – The bending of light when it encounters small objects. – The spreading out of light when it goes through a small opening.

Introduction •

The Point Spread Function • When an image is going to be acquired, we excite it with a light source and then use optics to guide the photons to our camera and collect them. • Under ideal conditions, we would see the photons merging into a single point, however in reality this is not the case. • The photons spread out and what we see on the picture is a smear localized around the ideal point. • This smear, or the response of the lens to a point of photons is called the Point Spread Function.

Point Spread Function Example • The captured image is the convolution of the actual object with its point spread function. • The convolution limits resolution, as several objects may me smeared together and look like a single object on the screen. This image was taken from Wikipedia

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