It takes a little more time to get into the role, but not very much more. In making a record you don't have the sense of projection over a distance as in an opera house. We have this microphone and this magnifies all details of a performance, all exaggerations. In the theater, you can get away with a very large, very grand phrase. For the microphone, you have to tone it down. It's the same as making a film, your gestures will be seen in close-up, so they cannot be exaggerated as they would be in a theater.
On making studio recordings - Callas : The Art and the Life (1974)