This may we learned some new skills in technical optics! Prof. Gross, worked a lot of years for the company Zeiss and afterwards teached at the Friedrich Schiller University Jena gave a weekend seminar in Dresden. We got impressive insights into modelling and simulation of different optics and optical systems. To do so we did spend a lot of hours in a seminar room of the computer science faculty, where Prof. Gross gave his lectures about topics such as optics design, aberrations and analysis of optical systems.