Whenever I play the violin a lot my fingertips start to hurt to a point at which it is painful to keep playing and this is just from around 3 to 4 hour a day practice which I don't consider to be excessive. Then come the calluses.
From what I hear people saying it seems that for guitarists it seems to be something normal, expected and even encouraged. See this question for example. However, for violinists I hear mixed things, most of them saying that it is not normal and it is probably a sign of using too much pressure on the strings.
Are these calluses normal or not ? Should I decrease the pressure on the strings ? Do great violinists have calluses on their fingers ? Do you ?