Via Ign.com:

Mark Hamill has revealed what could very well be the first photo ever taken of him as Luke Skywalker.

The actor shared the photo in a post on Twitter, which was taken during the first day of filming for Star Wars: Episode IV — A New Hope. Alongside the photo he said, “Taken in Tunisia early morning Day #1 waiting for my 1st shot (emerging from home for robot auction)-Perhaps the very 1st.”