love the value studies, the side profile face is superb phoeni, as for crits, the other guys facial proportion looks a little out, the face looks too long and narrow, however he may well have that sort of face.
your white values, are a little difficult to make out, i think i'm seeing a low energy bulb, a potato? possibly a can with pens, but i'm not sure to be honest, so i'd define your shapes a little to make it clearer. Very nice shading though, especially on the bulb.
your studies are going very well!