To my knowledge either way is "correct" in the sense that they reach the same conclusion when you do the math. The view of whether it is a field or virtual particles or if the field is made of virtual particles is just interpretations. I'm not 100% sure on this, but I have seen multiple threads arguing this subject and it looks to me to be true. Don't take my word for it, I'm sure a search here on PF for "virtual particles" would find plenty of threads on it.