Adobe Premiere Pro automatically attempts to preserve the frame aspect ratio of imported assets, sometimes changing the pixel aspect ratio, the frame dimensions, or both so that the asset does not appear cropped or distorted when used in a sequence. Assets created in an Adobe Creative Suite application contain metadata that allows Adobe Premiere Pro to make the calculations automatically and precisely. For assets lacking this metadata, Adobe Premiere Pro applies a set of rules to interpret pixel aspect ratio.

When you capture or import NTSC footage with the ATSC frame size of 704x480, the D1 frame size of 720x486, or the DV frame size of 720x480, Adobe Premiere Pro automatically sets the pixel aspect ratio for that asset to D1/DV NTSC (0.9). When you capture or import footage with the HD frame size of 1440x1080, Adobe Premiere Pro automatically sets the pixel aspect ratio for that file to HD 1080 Anamorphic (1.33). When you capture or import PAL footage with the D1 or DV resolution of 720x576, Adobe Premiere Pro automatically sets the pixel aspect ratio for that file to D1/DV PAL (1.067).

For other frame sizes, Adobe Premiere Pro assumes that the asset was designed with square pixels and changes the pixel aspect ratio and frame dimensions in a way that preserves the asset’s image aspect ratio. If the imported asset is distorted, you may need to change the pixel aspect ratio manually.

When you drag an asset into a sequence, Adobe Premiere Pro centers the asset in the program frame by default. Depending on its frame size, the resulting image may be too small or overcropped for the needs of the project. If so, you may need to change its scale. You can do this manually or have Adobe Premiere Pro do it automatically whenever you drag an asset into a sequence.

It is always a good idea to make sure that files are interpreted correctly. You can read an asset’s frame dimensions and pixel aspect ratio near the preview thumbnail and in the Video Info column of the Project panel. You can also find this data in the asset’s Properties dialog box, the Interpret Footage dialog box, and the Info panel.