Just for information purposes with reference to drawing apps. I recently downloaded the "Da Vinci Eye" app on to my smartphone and used it to draw this from a photo. It can turn any image on your phone translucent or transparent using a sliding scale, allowing you to peer right through the image to your paper underneath. It's good for creating a quick and accurate outline and then you just have to 'colour in' your tones from whatever photo you've chosen. The app cost me £3.69. Great fun! This is in one of my small sketchpads and is drawn using a 4B pencil.