
An interesting aspect of his work is that he often used photographies (his own or from magazines) as original from which he painted. These images show a characteristic haziness like a blurred photo, which makes it quite obvious that the images were painted after a photo and not after a real life scene.
Sometimes Gerhard Richter covered those photographic images with an abstract layer of paint with only parts of the "original" image shining through. All-in-all a very interesting discourse about photography and painting making you think about the relationship of both art-forms.
Here's another picture from the exhibition showing other works:

The exhibition is open until February 22nd. Highly recommended!