Many (most?) artists work with photos when they do portraits. The advantages are clear: the sitter is not forced into hours of boredom; the artist can draw and redraw the face in her own time; the hard work of going from 3D to 2D has been done by an apparatus. The problem, I find, however, is that there is a tendency for the portrait done in close dependence on a photo to often look “frozen”, stiff, and inhuman!
There is something in the drawing using stereoscopic vision with the breathing model in front of me, that captures the energy and reality of the living person better than a drawing done from a photo. The downside is that sometimes the resemblance slips away (and that can happen, maddeningly, with a slight mistake in the distance between the eyes or the length of the chin or the shape of an eyebrow!).
In previous centuries, the best artists could not only get a resemblance, but they also (amazingly) could retain the image of the person and repeat it from memory! However, part of this skill came about because artists redid work: redrew, repainted, reconceptualized the image, as can be seen in many Degas studies. I was not trained to do this, but I am going to be working this way for awhile to see what I can learn from it. The trick, I think, is to reverse engineer the image in the photo to recapture the vitality of the living model.
My friend Val was kind enough to sit for me recently for the drawings at the top of this post. I usually draw for about 1/2 an hour then take photos of my model. The drawing on the right was done from life; the one on the left from the photo I took during the same sitting. The drawings are, as always, watercolor pencil on paper.