According to the specifications the following aspect ratios for DCPs are valid:

The pixel array size and frame rate shall be one of the formats listed in the table below:

• 2K Scope (2.39:1) Resolution: 2048x858 FPS:24/1 or 48/1
• 2K Flat (1.85:1) Resolution: 1998x1080 FPS:24/1 or 48/1
• 2K Full (1.90:1) Resolution: 2048x1080 FPS:24/1 or 48/1
• 4K Scope (2.39:1) Resolution: 4096x1716 FPS:24/1
• 4K Flat (1.85:1) Resolution: 3996x2160 FPS:24/1
• 4K Full (1.90:1) Resolution: 4096x2160 FPS:24/1

Stereoscopic picture essence tracks shall be limited to the 2K formats, and shall have a frame rate of 48/1 and an edit rate equal to half the frame rate.