'X-Men: Days of Future Past': Patrick Stewart and Shawn Ashmore behind-the-scenes photos

Bryan Singer is at it again. The "X-Men: Days of Future Past" director is posting more photos to his Twitter account featuring sneak peaks at the upcoming movie. After posting a series of casting announcements on the social networking website, Singer also revealed a first look at Beast, played by Nicholas Hoult.

Singer followed that on April 14 with a photo of Sir Patrick Stewart, returning to his role as Charles Xavier, taking promotional pictures for the film. That tweet was captioned "Tomorrow it begins," which could mean April 15 was the official start of production on the movie.

Then he posted another picture on April 16, this one of Shawn Ashmore suited up as Iceman. Ashmore has orange dots all over his face, for tracking. Those dots help to track facial movement for CGI purposes.

As production on the movie continues, don't be surprised to see even more peaks at the movie from Singer. "X-Men: Days of Future Past" is scheduled to be in theaters July 18, 2014.

Check out both pictures below:

Photo/Video credit: Twitter