Operation Manual

65
Importing and adding media
Last updated 10/4/2016
Understanding aspect ratios
The aspect ratio specifies the ratio of width to height. Video frames have an aspect ratio (frame aspect ratio) as do the
pixels that make up the frame (pixel aspect ratio). Some video camcorders can record various frame aspect ratios, and
the NTSC and PAL video standards use different pixel aspect ratios. If an image of a circle appears oval-shaped, there
can be a mismatch between the aspect ratios of the image and your project.
Premiere Elements automatically attempts to detect and compensate for the pixel aspect ratio of source clips so that
distortion doesn’t occur. If a clip appears distorted in Premiere Elements, you can manually change its pixel aspect ratio.
It's important to reconcile pixel aspect ratios before reconciling frame aspect ratios. Misinterpretation of a source clip’s
aspect ratio causes incorrect frame aspect ratio.
Frame aspect ratio
Frame aspect ratio describes the ratio of width to height in the dimensions of an image. For example, DV NTSC has a
frame aspect ratio of 4:3 (or 4.0 width by 3.0 height). For comparison, a typical widescreen frame has a frame aspect
ratio of 16:9; many camcorders that have a widescreen mode can record using this aspect ratio. Many films are shot
using even wider aspect ratios.
When you add clips into a project with a different frame aspect ratio, decide how to reconcile the different values. You
can show a widescreen movie with a 16:9 frame aspect ratio on a standard TV with a 4:3 frame aspect ratio in two ways.
Use the Letterboxing technique to fit the entire width of the 16:9 frame into a black 4:3 frame. Black bands appear above
and below the widescreen frame.
Alternatively, use the Pan and scan technique to fill the 4:3 frame with only a selected area of the 16:9 frame. Although
this technique eliminates the black bars, it also eliminates part of the action. Premiere Elements automatically
letterboxes any 16:9 footage that you add into a 4:3 aspect ratio project.
Pixel aspect ratio
Pixel aspect ratio describes the ratio of width to height in a single pixel of a frame. Pixel aspect ratios vary because
different video systems make different assumptions about the number of pixels required to fill a frame. For example,
many computer video standards define a frame that has a 4:3 aspect ratio as 640 x 480 pixels. Pixels that are square,
which have an aspect ratio themselves of 1:1, perfectly fill the horizontal and vertical space the frame defines. However,
video standards such as DV NTSC (standard for DV camcorders in the U.S.) define a 4:3 aspect ratio frame as 720 x
480 pixels. Consequently, to fit all of these pixels in the frame, the pixels must be narrower than the square pixels. These
narrow pixels are called rectangular pixels, and they have an aspect ratio of 0.9:1, or 0.9 as they are commonly called.
DV pixels are vertically oriented in systems producing NTSC video and horizontally oriented in systems producing
PAL video. Premiere Elements displays a clip’s pixel aspect ratio next to the clip’s image thumbnail in the Project Assets
panel.