Hi! I have a couple of questions I'd like to ask related to this picture, if that is okay. Basically, I've been trying to figure out what pictures you can and cannot use when making studies like this, especially if you'd like to show them here on DA.
As far as I have gathered it is only okay to use pictures that are public domain or if you have expressed permission to use them.
But is it perhaps generally accepted that artists non-profit studies or practice drawings are exempt from this? Or could they perhaps be called "marketing" by demonstrating the artists skill?
In this case it is from a movie, so as long as you said from what movie it was nobody would bother.
If you study another artist (who is still alive) I would tell them and MENTION their names. Many painters don't do that because they see themselves superior to the photographer's work which is wrong. All artists should respect each other, so this is what it comes down to by the end.
As long as you give credit there is no harm done, and I can tell you from my own experience that living masters usually are very proud and honored when you show them that you have made a study after their work.