Thanks everyone for the comments and suggestions.
Karko: it’s funny, at the beginning my first idea had been to put the drawing on the panel beside him, but in the end I decided that for me this was too blatant and I hadn’t wanted the drawing to intefer with the cast shadow. With it on the table I guess a viewer has to work harder to find the story so I don’t know if it is the right decision, but at this point I’m afraid I don’t have time to change it as it would require changing the composition on the table.
Cabertevon: thank you for your kind comments - I’ve never got stars before 
Frotze: thanks David, especially for pointing out the shadows. I am learning XSI as I go on this one and had decided to deal with shadows with a shadow pass. In the end the shadow pass didn’t work well (not sure what I might be doing wrong) and I had sort of forgotten about them being too sharp in places. I’ve re-rendered with an area light (renders take about an hour at 4000 pixels high, so not too bad) to soften them up a bit (not too much though, as I want the profile to be readily discernible).
guterrez: thank you and you are right - the right-hand side needs some variation. I’m not to keen on cropping it closer as this would feel to me like it was severing his left leg (even though you can’t see it). I think I will add the barely visible highlights of a long curtain - more colour variation than obvious shapes.
Korendo: thank you - I did have some other objects to include (callipers and ink pot and quill) but just couldn’t fit them on the table in a pleasing way. Although this is the result of an obsession, the final act is compulsive as per the choleric type, so I wanted him to be a bit divorced from any thought of the consequences - the bleeding bowl on his lap is the only concession to that.
MartinNielsen: thank you - almost there 
Nemesix: thank you - funny and disturbing is good 




