Resolution and frame rate

When referring to high-definition television, the reference is actually to the number of lines in the vertical display resolution. High-definition television (HDTV) resolution is 1080, or 720 lines. By contrast, regular digital television (DTV) is 480 lines (upon which NTSC is based; 480 visible scan lines out of 525) or 576 lines (upon which PAL and SECAM are based; 576 visible scan lines out of 625). Additionally, current DVD quality isn't high definition, although the highdefinition disc system Blu-ray is, as was the now-defunct HD DVD format.

In high-definition mode, the 5D Mark II shoots in 1080p resolution as opposed to 1080i. The p stands for progressive scanning and redraws the image frame (all its lines) when refreshing each image. Designated by an i, interlaced scanning draws the image field every other line, or odd-numbered lines, during the first image refresh operation and then draws the remaining even-numbered lines during a second refreshing. To get an idea of how this works in theory, place your palms on a flat surface and then slide your hands toward each other, interlocking your fingers. Interlaced scanning in effect replaces one hand at a time to create a moving image. Interlaced scanning yields greater image resolution if a subject isn't moving but loses up to half the resolution and may suffer combing artifacts if the subject is moving. This accounts for the jagged visual effects in some fast-moving sequences.

There are three main frame-rate standards in the TV and movie industries:

► 60i. Designating 60 interlaced fields producing 29.97 fps, 60i is the standard video frame rate used for NTSC (National Television System Committee) television since 1941 and is used by DVDs and home-video camcorders.

► 50i. This frame rate of 50 Interlaced fields produces 25 fps and Is the standard for PAL (Phase Alternating Line), a color-encoding system used In broadcast television systems In many parts of the world. The 5D Mark II has video output settings for both NTSC and PAL and must be set correctly to view images on a corresponding TV right off the camera.

► 30p. In either SD or HD mode, the 5D Mark II is set to record video at 30 fps or 30-frame progressive. Progressive (noninterlaced) scanning mimics a film camera's frame-by-frame image capture and gives clarity for high-speed subjects and a cinematic-like appearance. Shooting in 30p mode offers video with no interlace artifacts.

One of the limitations of the current state of the technology today in relation to the 5D Mark II that many photographers might not realize at first is the HD output and storage decisions. It's wise to consider this before you begin creating huge HD video files for which you may not have appropriate output or storage capacity. Although you have a great tool to create high-definition movies with the 5D Mark II, output is limited by the devices you have at your disposal, and large high-definition files gobble up computer hard disk space in a hurry. HD content can be viewed by most computers over VGA, DVI, or HDMI feeds, Blu-ray discs, or by connecting the 5D Mark II to a high-definition TV monitor, as Canon recommends. This isn't always workable but may be the easiest method of viewing HD content until Blu-ray burners and players become more affordable and widespread.

To set the video resolution on the 5D Mark II, follow these steps:

1. Press the Menu button and then turn the Main dial to display the Set-up 2 (yellow) menu.

2. Turn the Quick Control dial to highlight Live View/Movie func.set. and then press the Set button. The camera displays the Live View/Movie func.set. option screen.

3. Rotate the Quick Control dial to select Movie rec. size and then press the Set button.

4. Rotate the Quick Control dial to highlight the resolution you want to create your movie in and then press the Set button.

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