PhotoStudio, six hours.
(Download will give you the biggest version.)
The American movie star Uma Thurman is one of my favourite actresses ever since the Stephen Frears movie "Dangerous Liaisons". She has a really interesting face and... we have the same birthday. Strangely enough this is the first time in a long time I drew her and... well, it seems I have to do it again as the resemblance leaves a bit to desire.
Several references for the pose and the face.
The best Uma portrait on DA was made by ~scabbed-doll
and can be found here: [link]
Some other bound Uma's:
By *SinnerDom [link]
... and the brilliant: [link]