How does Chuck Close use the grid method and value ?

Charles Thomas Close (July 5, 1940 – August 19, 2021) was an American painter, visual artist, and photographer. He made massive-scale photorealist and abstract portraits of himself and others, which hang in collections internationally. Close also created photo portraits using a very large format camera. He adapted his painting style and working methods in 1988, after being paralyzed by an occlusion of the anterior spinal artery. He died on August 19, 2021