The Child Portrait: 

This one is a drawing of our Autistic son Max in his clown costume from Halloween 2007.  It only took me a few hours to complete and is drawn on 14x17" paper.  There is a huge difference in drawing times when I get to draw from a very large original.  This photo was an extremely high resolution digital image measuring about 2000 pixels tall.  The better the resolution the better the drawing.  I can see many more details in a large scale digital photo or scan.