Restoration of the Sistine Chapel frescoes between 1980 and 1994. This most recent restoration had a profound effect on art lovers and historians, as colours and details that had not been seen for centuries were revealed. It has been claimed that as a result "Every book on Michelangelo will have to be rewritten". Others, such as the art historian James Beck of ArtWatch International, have been extremely critical of the restoration, saying that the restorers have not realised the true intentions of the artist. This is the subject of continuing debate. The frescoes on the ceiling of the Sistine Chapel had a number of interventions prior
Illusionistic ceiling painting sotto in sù". This was the prototype of illusionistic ceiling painting that was to become an important element of Italian baroque. Correggio at Parma took the illusionistic ceiling a step farther in his frescoes of Christ and the Apostles for the cupola at the San Giovanni Evangelista and in the "Assumption of the Virgin" in the dome of the Cathedral of Parma, which is Correggio's most famous work (1520–24); in these frescos Correggio treats the entire surface as the vast and frameless vault of heaven in which the figures float. In a visual continuity between the architectural interior and its