Archived - Final Cut Pro: DV and Widescreen Video Formats Explained
DV video has a frame size of 720x480 pixels. The width to height ratio of the frame is called the Aspect Ratio, and the Aspect Ratio of this frame size is 4:3. It is possible, however, to shoot video for playback using a different Aspect Ratio. The "wide-screen" Aspect Ratio commonly used by video is 16:9, and it allows video producers to create a wide screen experience similar to film.
Videographers and editors must bear in mind, however, that when shooting "wide-screen" video using standard definition DV camcorders, the recorded DV video frame is still 720x480 pixels. Shooting 16:9 visuals and recording them to a 4:3 frame size is referred to as shooting Anamorphic video. An anamorphic image is created when a wide frame is stretched into the same space as a normal frame, with the result being visible horizontal distortion (a "squished" look) in the video frame.
Figure 1 A Widescreen Image
Figure 2 Image Anamorphically Fitted into a 4:3 Aspect Ratio
The advantage of this is that producers can shoot wide-screen material using inexpensive equipment. The disadvantage of shooting anamorphic video is that everything in the Anamorphic frame looks thin and distorted on a normal monitor unless the image is adjusted, either by software or by pushing the 16:9 button found on high-end broadcast video monitors. This button rescales the video vertically as it is displayed on the monitor, giving it the proper widescreen dimensions.
Remember that 16:9 anamorphic video is supposed to look "squished" on a typical 4:3 monitor. Although this may seem odd, it is the correct behavior. When recording, transferring, editing, and outputting to tape, an anamorphic image should never be permanently rescaled in order to retain the full video resolution of the image for future use, either for display on a widescreen monitor, or for enlarging to film.
Since anamorphic video creates a widescreen experience by stretching a "squished" 4:3 image out to fill a larger area, fewer pixels are rescaled to fit a larger area. The only video format that actually has a larger frame, using more vertical and horizontal pixels to create a wide-screen image, is High-Definition video. High-Definition video is a completely different format, however, and is not covered in this article.
Rescaling anamorphic video in order to see the entire wide screen frame on a standard definition 4:3 monitor is called "letterboxing," and results in the loss of the maximum resolution available in the source footage. A letterboxed frame has two black borders both at the top and at the bottom of the frame (Laserdisc and DVD aficionados will be used to this). You should only letterbox your video when you are finished editing and want to deliver a tape that will look right on consumer equipment.
Figure 3 A 16:9 Letterbox image
Why shoot 16:9 video?
There are three main reasons to shoot 16:9, or anamorphic video:
1. Because it looks neat. Even if you end up letterboxing the eventual output for standard definition televisions, viewers tend to associate the widescreen look with a cinematic feel. A wide screen also allows video-makers more room for creativity in their shot composition.
2. Preparation for transfer to film. Film and video both have different aspect ratios. 35 mm film, with an aspect ratio of 1.85:1, is wider than the standard 4:3 ratio of broadcast video.
Figure 4 Aspect Ratios Compared
Those who shoot standard 4:3 video end up having to crop off the top and bottom of the image in order to resize it to fit the film frame, losing resolution and therefore quality.
Figure 5 Cropping 4:3 Video to Fit into a 1.85:1 Frame
Videomakers shooting 16:9 will be able to make higher resolution transfers by virtue of not having to crop out as many pixels (16:9 is still a bit narrower than the American film standard 1.85:1).
3. Looking to the future. High-Definition video also has an aspect ratio of 16:9. While High-Definition video is not in common use yet, eventually the entire broadcast industry will move to High-Definition video as the standard means of broadcast. Videomakers who want to be able to resize their productions to take advantage of the new frame size of this upcoming standard should shoot 16:9 anamorphic.
How can I acquire Anamorphic Video?
Anamorphic video can be acquired in one of two ways:
1. Using the 16:9 button found on most camcorders. This method, while easy and inexpensive, yields the lowest resolution. What is actually happening is that the camcorder crops off the top and bottom of the screen, then stretches this smaller widescreen image vertically to fit the full 4:3 aspect ratio, thus producing the necessary anamorphic distortion before recording the image to tape. This method is the less desirable of the two as it uses fewer pixels, actually reducing the available resolution, and can result in degradation of the final image. On the other hand, an advantage of this method for those seeking convenience over quality, is that many camcorders embed information in the video signal that indicates whether or not it was recorded in 16:9 mode. Final Cut Pro 1.2.5 can read this information and automatically capture and output it in the correct fashion.
2. The second method involves using an anamophic lens. An anamorphic lens is a wide angle lens that optically distorts the 16:9 image into a 4:3 frame before sending it into your camcorder's CCD (charged coupling device). Because this is done optically, the result is clean, clear, and takes advantage of the full resolution of the DV frame. This method is recommended for users looking for the best possible quality.
How Final Cut Pro 1.2.5 handles 16:9 Video
As of version 1.2.5, Final Cut Pro has the ability to properly display anamorphically captured material at the correct 16:9 aspect ratio directly on your computer display without rendering. Transitions such as the "Oval" and "Star" iris are correctly shaped, and all geometry settings automatically take the 16:9 aspect ratio into account.
The Anamorphic Display information referred to in this section affects playback display on your computer monitor only. It does not affect DV or QuickTime rendering, and it does not alter the resolution of captured QuickTime clips in any way. All DV clips are still captured and output with a frame size of 720x480.
Figure 6 Final Cut Pro with 16:9 DV Clips Loaded Into Both the Viewer and Canvas
Importing Anamorphic 16:9 Clips from Tape
Final Cut Pro gives you a great deal of flexibility when it comes to importing Anamorphic 16:9 material for editing. Some cameras have the ability to embed information regarding the user's selected aspect ratio directly onto the videotape. When a user presses the "16:9 Wide" button on these cameras, the DV stream recorded to tape includes this information, and Final Cut Pro 1.2.5 will automatically detect this and mark the resulting imported QuickTime clip as Anamorphic 16:9. This will happen regardless of whether or not the "Anamorphic 16:9" button is checked in the "Capture" Preferences tab.
Figure 7 The Anamorphic 16:9 checkbox in the Capture Preference Tab
Those using an Anamorphic Lens to achieve the 16:9 look, as previously described, are actually recording their footage at a 4:3 aspect ratio. As a result, it is not automatically identified as 16:9 material by Final Cut Pro. If you are using an Anamorphic Lens, checking the Anamorphic 16:9 option in the "Capture" Preferences tab marks all subsequently imported clips as Anamorphic 16:9.
Note: With this option turned on, all clips are marked as 16:9 regardless of whether or not they are actually supposed to be, so be careful to deselect this box when recording regular, non-anamorphic 4:3 material.
Switching a clip between Anamorphic 16:9 and Standard 4:3
Once a clip is imported, its aspect ratio can always be changed by going into the item properties for that given clip, and clicking the Anamorphic 16:9 button. This information is available only in Final Cut Pro, and is saved back to a QuickTime file by rendering it out from an appropriately configured sequence with 16:9 either enabled or disabled.
Figure 8 The Anamorphic 16:9 checkbox in the Item Properties Window
Importing Anamorphic 16:9 QuickTime Clips
If you are importing clips already stored on your hard drives, you can have Final Cut Pro 1.2.5 automatically check to see if they are set to a 16:9 aspect ratio by turning on the "16:9 Import Check" button in the "General" Preferences tab. This 16:9 information gets embedded into QuickTime files either by capturing video clips that have it from tape, or by rendering out a sequence set to be 16:9 anamorphic as a QuickTime file.
Figure 9 The 16:9 Import Check checkbox in the General Preferences Tab
Editing with Anamorphic 16:9 Sequences
When editing, the Viewer automatically detects which clips are marked as Anamorphic 16:9 and which are not, and adjusts accordingly. Sequence playback and clips displayed in the Canvas work differently. Sequences that are not set to Anamorphic 16:9 will need to render any 16:9 clips that are edited into them, even though they are displayed properly. To avoid this, always edit 16:9 material into a sequence specifically set to Anamorphic 16:9.
New 16:9 sequences can be created by changing the default preset in the "Sequence Presets" Preferences tab. Final Cut Pro 1.2.5 has additional presets that weren't available in version 1.2 or earlier. To change the default Preset for new sequences:
1. Select a new preset from the list shown in the "Sequence Presets" tab
2. Click the "Set Default" button
3. Click the "OK" button
Notice that the new default sequence has an icon indicating this to the left of it in the list. Any new sequences created are now created with these settings.
Figure 10 The NTSC and PAL 16:9 DV Presets (the Default 4:3 preset is shown on top)
Existing Sequences with no clips edited into them can be switched to 16:9 by opening up the Sequence Settings window. This is done by selecting the sequence to be modified and either selecting the Sequence>Settings menu item, or Control + Clicking the sequence icon to bring up the contextual menu, which also has a Sequence Settings menu item. Once the Sequence Settings window is open, Anamorphic 16:9 can be enabled or disabled through a checkbox.
Note: This should only be done prior to adding any 16:9 clips. If a 16:9 clip is edited into a 4:3 sequence, it will display properly but require rendering. If that sequence is then changed to 16:9 without first removing the edited clip, the clip will not look correct.
Figure 11 The Anamorphic 16:9 checkbox in the Sequence Settings
Exporting Anamorphic Video to Tape
When outputting an edited sequence using anamorphic video to tape, you have two choices, depending on what kind equipment you want to play back from:
1. You can simply output it as is, looking "squished" on a 4:3 monitor. This is the preferable option if you're planning on playing back your video on hardware that will compensate for the proper aspect ratio or if you're planning on transferring to film. High-end broadcast monitors can rescale for 16:9 at the push of a button, and some specialty widescreen monitors popular with home theater enthusiasts will do this as well.
2. If you're unsure who is going to be viewing the tape and you want undistorted playback on a standard 4:3 monitor, you can manually letterbox your video. This will require rendering your entire edited sequence, so allocate some time for this process. To letterbox your edited sequence:
a) Open the 16:9 sequence in the Timeline.
b) Create a new sequence that is not 16:9 anamorphic and open it in the Timeline.
c) Drag the 16:9 sequence's icon from the Browser to the Overwrite area of the Edit Overlay in the Canvas.
d) Render the new sequence, then print it to tape.
Instead of outputting to tape, users may also render a QuickTime movie with a rectangular, 16:9 framesize. For examples of 16:9 framesize, see some of the movie trailers at http://www.quicktime.com/trailers/ . To export your edited sequence with a 16:9 rectangular frame size:
1. Choose "Export" from the File menu and "QuickTime" from the submenu.
2. Click the "Options" button
3. In the Video section, click "Size," then click "Use Custom Size"
4. Enter values for the width and height so the desired height is 9/16 of the desired width (to determine this value, multiply the width by 0.5625), then click OK.
Two example frame sizes using this ratio are:
a) If you are exporting from the native DV-NTSC frame size of 720 x 480, set the output frame size to be 720 x 405.
b) An example of a smaller 16:9 frame size would be 400 x 225
The following manufacturers supply anamporphic lenses. See their websites for more information about lens adaptors for your individual camera:
- Century Precision Optics - http://www.centuryoptics.com/
- SMS Productions - http://www.smsprod.com/products/lenses.html
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