As a fan of the Doctor, and especially the 10th, I must start this by saying what a wonderful portrayal this is. I honestly thought this was an actual picture, and I am astounded at the detail you put into this true work of art.
I gave this 5 stars on Vision because you efficiently captured what Doctor Who is. The Tardis background makes you feel as if you are actually accompanying the Doctor on one of his many marvelous adventures. You were able to capture the emotional depth of David Tennant's 10th Doctor. His eyes especially possess the wisdom of the Doctor, even though his youthful appearance is the first thing you see. You even added the infamous sonic screwdriver, yet did not make it the focus of the portrait, which is sometimes hard to do. Also, I really enjoy how the picture does not look posed. It is as if we have simply said his name, or if he just happened to look over at us.
I gave it 5 stars for originality because you don't often see this picture of the 10th Doctor drawn. I believe that your expertise alone makes this picture unique.
As for technique, I gave it 5 stars because your attention to detail is impeccable. You have truly captured the reason we all love the Doctor- because he is him. The thing missing from so many drawings, especially those containing color and not in black and white is the realistic touch that is difficult to draw in. I am astounded at this work, and have added you to my watch list.
And last but not least- impact. 5 stars. I do not know how to describe my emotional feelings except for saying that I feel at home. As a Doctor Who fan I have always wanted to travel with him on fabulous adventures across time and space. This picture really makes me feel like I am with him, like I have gone on many journeys with him and that him and I have begun to think on the same track. Like I am his companion.
Congratulations on this fine work of art. I appreciate artists such as yourself and immensely enjoy going through your gallery. The only thing I would say to do is to draw more pictures- soon!