Contact potential thesis advisor with no topic in mind Is it okay to contact potential advisor if you have no specific topic in mind about your dissertation? I wanted to pursue graphics for masters, its a bit difficult narrowing it down. Is it okay to ask them for a specific topic?
I'm a professor in Germany and I throw any master's students out who come asking me for a topic. It needs to be a question they want answered or some computing question they want to explore. Bachelor's I do a bit of hand-holding on. 

You should research the interests of the professor and see if he or she is likely to be interested in your question. And do check if the professor is male or female before writing your letter. All emails addressing me as Herr Professor get piped to /dev/null.