Understanding Recordable Home Video Formats

It's summer, and I've spent a lot of time on vacation with the kids. This year, we decided to get a new camcorder; we opted for Sony's DCR-HC42 Mini-DV Handycam Camcorder, which supports a widescreen recording mode and required me to research digital video (DV) cameras and the way they record video. Although making home movies on a PC or Macintosh is easier than ever, the process is still difficult to understand because of all the confusing technology involved. So this week, I look at some of the video recording formats you can consider when shopping for a new camcorder. In a future article, I'll explain the video formats you can use when it's time to edit your masterpieces and share them with the world.

DV
Today, the vast majority of digital camcorders natively record in DV format. DV is a compressed—but high-quality—video format that uses the standard 4:3 screen dimensions. In other words, DV video is roughly square, just like most TV screens. Because DV is an international standard, virtually all digital camcorders and computer-based video-editing packages use the format. DV uses 480 lines of vertical resolution, and most computer-based editing packages translate these signals into a 720 x 480 picture.

DV Widescreen
Some newer camcorders, including the Sony model I'm currently using, support a true 16:9 widescreen mode, called DV Widescreen, in addition to the standard DV format. You might think DV Widescreen is simply the same old DV format with a couple of black bars added to the top and bottom of the screen to emulate true widescreen, but DV Widescreen is more sophisticated than that. Instead of hiding valuable video data behind a pair of black bars, DV Widescreen records video onto standard DV tape using a higher horizontal resolution. The resulting image has better resolution—and better quality on the same camera—than standard DV. Like DV, DV Widescreen uses 480 lines of vertical resolution. Most computer-based editing packages translate these signals into an 853x480 picture.

Does DV Widescreen have any problems? Yes, it does. Because the format is so new, many video-editing applications don't work correctly with it and instead import DV Widescreen as standard 4:3 DV, squishing the video image into a square box and making everything look tall and skinny. The most obvious offender is Windows Movie Maker 2, which comes free with Windows XP. However, more sophisticated (and more recently updated) editors, such as Adobe Premiere Elements (Windows) and Apple iMovie HD (Mac), natively understand Widescreen DV and can output edited movies that are recorded in this format in true widescreen.

By the way, some camcorders fake widescreen by simply placing black bars over a 4:3 DV image and making something that looks like widescreen but offers a video image of significantly reduced resolution. Other camcorders offer electronic widescreen cropping but feature a 4:3 charge-coupled device (CCD), which simply drops pixels to achieve the 16:9 screen dimensions. Don't be fooled by either trick. True DV Widescreen is a nice stepping-stone to the 16:9 high definition (HD) resolutions of the future, but fake widescreen just hides portions of your video or drops resolution. If you want to use this format, make sure you get a camera that actually works natively in widescreen.

HDV 720p
This 16:9 high definition video (HDV) format uses 720 lines of vertical resolution rendered in a single pass. This method of video rendering is called progressive video rendering, thus the p in the format's name. (By comparison, so-called standard-definition TV sets—that is, most TVs—are sometimes referred to as 480p because they typically offer 480 lines of vertical resolution. Standard DV, therefore, can be thought of as 480p.) Some computer-based editing packages render HDV 720p video in 1280 x 720 resolution.

HDV 1080i
This 16:9 HD format uses a whopping 1080 lines of vertical resolution—about two and a half times the resolution of a standard DV signal—but renders the screen in an interlaced method that requires two passes. (The I in 1080i refers to interlaced.) Some computer-based editing packages render HDV 1080i in 1920x1080 resolution.

Interestingly, both HDV 720p and HDV 1080i can compress HD video signals on a standard DV tape. However, there's some debate about whether a progressively rendered HD 720p signal is cleaner or better looking than an interlaced HDV 1080i signal. Suffice it to say, both look great, but few consumer-oriented camcorders on the market today can handle either format. Sony's recently released HDR-HC1 HDV 1080i Handycam Camcorder is the least expensive at $2000. It handles 1080i HD video, if that's any clue.