I've been speaking with a professor with regards to admission into a PhD program at a top European University, and things have been going well so far. The only problem is that it isn't "officially" in my field of choice.
To be more specific, the degree label will be "Mechanical Engineering" (as it was for my B.Eng and M.Eng), while most of the work will involve Numerical Computing and 3D graphics; just that it will be in the Mechanical Engineering domain. In fact, one of the reasons the professor has expressed interest in hiring me is because it isn't common for Mechanical Engineers to also be experienced programmers in the field.
While I'm certainly excited at the opportunity, I am also feeling a little bit reluctant, because I wanted my degree to be titled "Computational Science" or "Software Engineering". The reason being is that I don't want to be seen as an "inexperienced" developer after spending 4 years in a program doing exactly that. The concern might seem shallow, but I don't want to commit 4 years of time I could be using to further my career.
Regardless of my reasoning, is it possible/common to ask for admission into a different faculty than my supervisor, while still being supervised by them? How much effort, if any, should I expend to make sure that the field I am accepted in is the one I want, while working with the same professor? What alternatives are there to advertise my qualifications as a software developer/computational scientist if I choose Mechanical Engineering? And finally, if at all, how will this limit/extend my options in the future?