Christmas Lecture 2020
Dürer, Dante and Crivelli: Geometry in image analysis

Munich on New Year's Eve: Is this picture a photomontage? The geometry provides the answer.
Geometry as the key to truth. Professor Jürgen Richter-Gebert gave the Christmas Lecture 2020 on "Dürer, Dante, and Crivelli: Geometry in (Forensic) Image Analysis." The digital lecture appeared on Richter-Gebert's YouTube channel on 17 December 2020 at 16:00. You can also watch the video here:
At the same time, Jürgen Richter-Gebert will answer your questions in the YouTube Live Chat.
The Christmas lecture provides a brief look at the history of perspective from the Stone Age through the Middle Ages to the Renaissance. Using brief examples, Richter-Gebert reveals why much is a matter of perspective. The lecture is held in German.

left: Cave painting of a bison, Altamira, 16,500 to 13,000 BC: Colors and shading create perspective; right: Albrecht Dürer: "The Draughtsman of the Lute," 1525, woodcut of a construction arrangement for perspective drawing
Carlo Crivelli: "Annunciation with St. Emidius", 1486, London, National Gallery
Crivelli's Annunciation
The "Annunciation with St. Emidius" by Carlo Crivelli is a remarkable work from the early Renaissance. The main scene features the Archangel Gabriel, who is on his way to Mary and is stopped by St. Emidius, the bishop.
In accordance with church doctrine of the time, the artist employs the perspective of meaning, meaning that the size of the subjects corresponds to their importance, not their position in the painting. However, in many details the artist shows that he knows how to use perspective correctly.
Goal! Isn't it?
In 2014, Professor Jürgen Richter-Gebert receives a call from the BILD newspaper, which asks him for a mathematical analysis. It's about soccer.
Cup final on 17 May 2014: Is the ball behind the line or not?
Cup final of the German Soccer Association 2014, FC Bayern against BVB, 64th minute: Dortmund demands a goal. After a header by Hummels, the ball is on its way into the Bayern goal. But Dante leaps in and knocks it away. Was the ball already in the goal? Can you calculate that from a photo?
Geometry as a forensic method
In the Christmas Lecture 2020, Professor Jürgen Richter-Gebert decodes images using mathematics. For example, he clarifies whether a New Year's Eve picture from Munich is a photomontage.
It's a great way to end 2020, and we'd love to have you join us!