Textbook/workbooks to learn Geometrical Optics This coming up semester I will be attending my first Optics course, which is engineering based. What are some good textbooks or resources for Geometrical Optics? We are using the Pedrotti 3rd edition book, but I would rather have backup information
 A: "Engineering Optics" is a very broad, messy subject. Indeed the text you cite is a very broad, comprehensive document. It is therefore likely that your instructor has a very particular path they want to follow, and you'll need to see what that is before knowing what to research. I'd say follow the instructor, and if something takes your interest then perhaps ask for further texts on that particular topic. Geometric optics itself is a few concepts, and any good text will cover it:
Born & Wolf, "Principles of Optics"
Hecht & Zajak, "Optics"
both contain good summaries of geometric optics, with the Born & Wolf one being much more thorough, but more arcane (the notation used in equations is very old and hard to read). You'll need to know Snell's law, lensmaker's equation, the Gullstrand power equation (incidentally, this is the very same Gullstrand of the Gullstrand Painlevé river co-ordinates for the Schwarzschild blake hole metric in general relativity) and the concepts of principal planes and points of a lens system and then that's pretty much it, aside from practice. 
Aberration analysis by geometric optics is possible, but seldom used now: one's time is better spent learning to drive design software. However:
Virendra Mahajan, "Optical Imaging and Aberrations"
Viendra Mahajan, "Fundamentals of Geometrical Optics"
both have some quite interesting expositions on the theoretical underpinnings of aberration. You probably won't use them in engineering, but your concept of what you are doing will be sounder for having read Mahajan.
Engineering is not like physics or mathematics, where one can say that there are eternal concepts that underlie each subject and which everyone wanting to understand them need to know. Rather, engineering is a collection of techniques and knowledge of technology of the day applied ad hoc to find the least worst solution maximally approaching the design goal.
Smith, "Modern Optical Engineering"
is a pretty good summary of the current state of the ad hoc art. 
