I received a couple of questions about a term I used the other day when I said a picture was "in drawing." As far as I know this is not an optical term, or at least I never use it that way. It's a term from Renaissance art. The idea of being 'in drawing' or 'out of drawing' was common in representational art at least through the 19th century, although for obvious reasons it seldom comes up today. 'Drawing' in this sense meant rendering something sensically— with its surfaces arranged and presented two-dimensionally so that the known structure and the volume of the object presented could be deduced from its surface. This was considered so important that some painters are seen doing violence to proportion so they could render things in drawing, as in the detail from Ingres here in which the poor woman's right upper arm seems to be about six inches longer than her left upper arm.
When photography came along, one aspect of it that was most shocking to prevailing sensibilities was that it was utterly serene about rendering well-known objects radically out of drawing. Willy-nilly, it could show human heads at such an angle that the features seemed bizarre; it foreshortened and exaggerated; a hand might look like a claw. It could catch a view of a man walking that made him look like he had only one leg. The simple visual idea of cropping off an arm or a head because it fell outside of the frame, which the camera did casually, seems never to have occurred to Poussin or Raphael. As Peter Galassi and others have pointed out, some of these radical sunderings of convention began showing up in paintings very soon after photography’s invention. Degas, one of history's master draughtsmen, quickly adopted photographic visual quirks in his paintings and drawings, including one-legged walkers and radical crops.
Nowadays, of course, showing something out of drawing is a way to make ordinary photographs interesting. It adds mystery and amplifies photography’s undertone of surreality. Or, it might just be mystifying. In my photograph at the top of this post (solidly in the category of "significant failures"), a horse fighting its reins is tossing its head up and away from the camera. The horse's head in this picture doesn’t look much like a horse's head; in fact it doesn't look much like anything we think we’ve seen. Moments like this, frozen on film, make us aware of how much of actual visual experience we choose to disregard.