Adobe Premiere Pro CS4 - Manual (Page 60)

54 USING ADOBE PREMIERE PRO CS4
Project setup
Last updated 11/6/2011
About square-pixel footage
Many graphics and animation programs generate square-pixel assets meant for display on square-pixel computer
monitors. Premiere Pro, however, typically generates files with non-square pixels for display on television sets.
Premiere Pro automatically conforms square-pixel assets to the project pixel aspect ratio. After the asset is conformed,
however, it no longer has its original frame aspect ratio. Also, its frame aspect ratio is not likely to match that of the
project, even if it did before it was conformed.
For example, suppose you generate a square-pixel asset at 720x540 and import it into a Premiere Pro DV project with
an aspect ratio of 720x540. In this case, the asset is wider than the screen when it is conformed. You can use the Scale
control to set the size of the asset frame within the project frame. However, to preserve the asset frame aspect ratio,
Premiere Pro often either crops the asset or frames it within black bars.
You can prevent this cropping and framing by carefully generating assets from your square-pixel graphics or
animation programs. Choose a frame aspect ratio that, when conformed, matches the project frame size exactly. For
best results, use programs such as Adobe Photoshop® and Adobe After Effects® that include pixel aspect ratio settings.
Set the frame dimensions and pixel aspect ratio to match the dimensions of your project. If the pixel aspect ratio setting
is unavailable in your program, do not try to match the frame dimensions (for example, 720x540). Instead, ensure that
the overall frame aspect ratio matches that of your project (for example, 4:3 or 16:9). Premiere Pro automatically
adjusts the video so that it is not distorted.
If your square-pixel program requires frame dimensions, use the option that matches your project output:
• 4:3 DV (NTSC) or ATSC SD—create and save the square-pixel file at 720x534.
• 4:3 D1 (NTSC)—create and save the square-pixel file at 720x534.
• 4:3 DV or D1 (PAL)—create and save the file at 788x576.
• 16:9 DV (NTSC)—create and save the file at 864x480.
• 16:9 D1 (NTSC)—create and save the file at 872x486.
• 16:9 DV or D1 (PAL)—create and save the file at 1050x576.
• 16:9 1080i HD—create and save the file at 1920x1080.
• 16:9 720p HD—create and save the file at 1280x720.
Using assets with various aspect ratios
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 Premiere Pro to make
the calculations automatically and precisely. For assets lacking this metadata, 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, Premiere Pro automatically sets the pixel aspect ratio for that asset to D1/DV NTSC (0.91).
When you capture or import footage with the HD frame size of 1440x1080, 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, Premiere Pro automatically sets the pixel aspect ratio for that file to D1/DV PAL (1.094).
For other frame sizes, 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 image aspect ratio. If the imported asset is distorted, you
can change the pixel aspect ratio manually.