MEASURING AND SIMULATION OF POINT SPREAD FUNCTION AS A BASIC PROPERTY OF AN OPTICAL DEVICE.

None of optical devices is perfect. Each lens has some errors, e.g. tilt, coma, spherical or chromatic aberration. The more lenses are in the optical device the more errors can reveal. All these imperfection accumulates and multiplies during the path through the optical device. It is necessary to know how the light passes through and interacts with each optical element. There are some possibilities of simulation of these defects. One of these methods is ENZ (Extended Nijboer-Zernike) theory which can be set up for different light condition and different aberration. There is also possibility to measure this property. As will be shown in this article I made this experiment using microscope and microscopic objects as an example of optical device with more lenses and optical elements. Measurements in combination with image analysis (entropy calculation) and 3D reconstruction give us overview of distortions which undergoes the original image. Results of both methods simulation and measurements can be used for improving of the original image. If we know how the image is distorted the knowledge of PSF (Point Spread Function) can help us to remove this distortion and obtain better image. This can be done using deconvolution function and the known PSF as a kernel for this function. Using simulations and PSF measurements can also help to improve resolution of the image and reveal more details. This can be helpful in many different fields, for example in biology, astronomy or in analysis of satellites or aerial photos. [ABSTRACT FROM AUTHOR]