Verocchio's specialty was perspective, which artists at that time had just started to get the hang of, but Leonardo quickly mastered the challenge. .
When Leonardo wasn't working in the studio, he explored the city of Florence. He made many observations and sketched them in his notebook. He even watched the construction site for the great cathedral being built and made detailed drawings of the machinery operating there. It dawned on him that objects were not composed of outlines, but were actually three-dimensional bodies defined by light and shadow (Vezzosi 30). This technique called chiaroscuro gave his paintings the soft, lifelike quality that made older paintings look cartoon-like and flat. Leonardo quickly surpassed Verocchio, and by his early twenties he was famous (http://www.mos.org/sln/Leonardo/LeoHomePage.html). In June 1472 Leonardo was listed in the red book of painters from Florence with a membership in the painters guild of Verocchio that ended the apprenticeship of Leonardo. .
A year later in 1473, the first works of Leonardo were created. One was a pen-and-ink drawing of the Arnovalley he made on August 5th. What is fascinating about the drawing is that Leonardo drew the landscape in a way that it could be real. No other artist had achieved this before. By the age of 21 Leonardo was a skilled painter. In 1476 Leonardo and Verrocchio did a painting called Baptism of Christ. This painting was an order for Andrea del Verrocchio from the cloister S. Salvi. Leonardo painted the front angel and the landscape. You can tell the difference between the two artists because of the way each painted the angels. Verrocchio was stunned at how well Leonardo's angel was painted. The hazy features of the background show he had already begun to develop his sense of aerial perspective. It is believed that Leonardo had his own workshop between 1476 and 1478, because he got two orders during this time (Vezzosi 40).