AfterEffects

Determine the original field order

The field order for an interlaced video footage item determines the order in which the two video fields (upper and lower) are displayed. A system that draws the upper lines before the lower lines is called upper-field first; one that draws the lower lines before the upper lines is called lower-field first. Many standard-definition formats (such as DV NTSC) are lower-field first, whereas many high-definition formats (such as 1080i DVCProHD) are upper-field first.

Note: Upper-field first corresponds to Even Field First in an ElectricImage file.

The order in which the fields are displayed is important, especially when the fields contain motion. If you separate video fields using the wrong field order, motion will not appear smooth.

Some programs, including After Effects, label the field order when rendering interlaced video files. When you import a labeled video file, After Effects honors the field order label automatically. You can override this field order by applying different footage interpretation settings.

If a file does not contain a field order label, you can match the original field order of your footage. If you are not sure which field order was used to interlace a footage item, use the procedure below to find out.

  1. Select the item in the Project panel.
  2. Choose File > Interpret Footage > Main.
  3. In the Interpret Footage dialog box, select Upper Field First from the Separate Fields menu, and then click OK.
  4. In the Project panel, press Alt (Windows) or Option (Mac OS) as you double-click the footage to open it in the Footage panel.
  5. If the Time Controls panel is not visible, choose Window > Time Controls.
  6. In the Footage panel, find a segment that contains one or more moving areas.
  7. Using the Next Frame button  in the Time Controls panel, step forward at least five frames in the Footage panel. Moving areas should move consistently in one direction. If the moving areas move backward every other frame, the wrong field-separation option has been applied to the footage.
    Note: Analog capture cards can vary. DV or footage captures from IEEE 1394 (FireWire/i.Link) are always lower-field first.