Changing Research Groups

I am still early on in my PhD. I have not passed my comprehensives (or even began studying for them yet), but I have finished my courses. Over the past year, I began working with a group that I initially felt was a good fit for me. At the time, they were the only ones working in this area in our department. However, as time has gone on, I have realized that my professor has absolutely no idea about my field and their relation to it is completely from a different angle (hardware vs software). They are unfamiliar with the conferences in my area, acceptable standards, state-of-art work, etc. In fact, the other day I was told that everything he knew about my area he learned from me. Originally, I thought they were active in this field, but actually they are in a COMPLETELY different field altogether. Recently, we hired a new professor that I am certain is in my field (publishes in the conferences of my field, etc.). I have decided to switch and begin working with this new faculty member. Is this unusual? I am very scared of my current faculty member and have heard horror stories. By the way, he is a retired professor (emeritus) but still can advise me.. but at this point I dont think I want it!