[Chris Saper]

Elizabeth,

You already have all the information you need with the source photo in his home. Decide on how large the head will be and how large your surface needs to be to accomodate the composition. Use a thumbnail sketch for this, same proportions as the finished piece. Enlarge the source photo to some reasonable size so you can see what's going on.

Then when you have the photo at hand, just measure the relative sizes of the items in the background, compared to whatever unit of measurement you choose in the source photo. It's the same thing you would do in open studio, just compare a new measurement to one that you know is correct. (For example, the height of the print on the wall is about the same as the distance between his chin to the edge of the hat's brim.) Match the angles in the interior; you'll need to use a straightedge, and you must follow perspective. Decide compositionally what you are going to do about the candle at the right hand side. Personally, I like it, but you may want to give yourself a couple of inches of wall to the right of it.

Most importantly, you have to replicate the light source in the resource photo, which shouldn't be too difficult. Set up your primary light to mimic the shadow and light pattern on his face, and you will also need a fill light for the cool secondary light which very strongly illuminates the fireplace. If I were you, I'd sketch the entire composition out before he comes to pose for you, and paint at least enough of the background to show value and color, so you can make good judgments about how to select colors for the skin tones.

Good luck! This looks like a fun painting.