These "excursions" into astronomical optics discuss innovative, often radical, suggestions for the design of optical instruments. Providing a storehouse of ideas and approaches not available elsewhere, Mertz suggests opportunities for further exploration and development rather than proven solutions. Covering a wide array of topics, from x-ray telescopes to gravitational lenses and from microscope objectives to Fourier transform spectroscopy, the excursions share a common thread of optical science related to astronomy. The book should thus interest researchers and graduate students in astronomy, optics, and optical engineering. Appendices provide Fortran code for some of the design techniques discussed in the book and for Monte Carlo image synthesis