DV Technology and the Camcorder
- About DV
- Matching a DV Camcorder to Your Shooting Style
- Access to Controls
- Camcorder Resolution and Picture Quality
- What Are NTSC/PAL/SECAM Broadcast Formats?
- What Do You Need to Know About Scanning Modes?
- Do You Need Automatic Camcorder Controls?
- Optical vs. Digital Zoom
- Audio Options
- Getting DV into Your Computer
- Your Mission
This chapter is from the book
This chapter is from the book
This chapter is from the book
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Most digital video starts with a camcorder, and choosing the right one may be the single most important decision you have to make on your project.
Which camcorder would an experienced cinematographer advise you to use? What features would a skilled video editor urge you to look for? What would a professional camcorder operator tell you about which automatic controls she uses most often—and which make her job harder?
Before you buy or rent a camcorder, you need to know the answers to those questions, and a lot more. You'll find them in this chapter.
Some of this information, which ranges from video formats to image resolution, color space, and TV broadcast standards, is fairly technical. You'll find more detail in Appendix A, "Digital Video Technology in Depth," where videomakers with a driving need to know as much as possible about the technology can turn for enlightenment.
Many of you may be tempted to skip this overview of DV technology, especially if you already own a DV camcorder. But take it from a couple of pros: The more you know about DV technology, the better prepared you'll be to buy, rent, shoot, and edit successfully.
Although the abbreviation "DV" obviously stands for "digital video," and could refer to all digital video formats, we'll follow standard practice and use it only when we want to refer to DV—the popular format that's currently democratizing video. DV is the least expensive, fastest-growing format on the market, and is also the native format used by most desktop editing systems. For the money, DV offers the best value you can find.
We'll use the term "digital video" to refer to DV plus all those other formats that are not "DV."
About DV
Development of the video recording standard known today as DV began in 1993. The first DV camcorder—the Sony DCR-VX1000—appeared two years later, and the DV industry has been on a rocketship ride ever since.
One reason DV became technically feasible was because new compression techniques made video data files much more compact at the same time that processing chips in camcorders and PCs were becoming more powerful. A DV tape recording or computer file requires only one-fifth the data bits of the uncompressed digital sig-nal, and the picture quality is almost undegraded. (For more information, see "DV Technology: Under the Hood" in Appendix A.)
Consumer vs. Professional DV
There are actually two separate specifications for DV: consumer and professional. Some of the key differences are summarized in Table 3.1. Simply stated, consumer DV recordings don't meet television broadcast specs, and professional DV recordings do. The people who care most about this distinction are television producers, engineers, and news crews. For most filmmakers and corporate videographers, especially those who aren't interested in broadcast distribution, the technical differences are relatively trivial.
Table 3.1. Key Differences Between Consumer and Professional DV Camcorders
|
Consumer |
Professional |
|
|
Color space |
4:1:1 |
4:2:2 (Broadcast spec) |
|
Audsio sync |
Unlocked: ±1/3 frame |
Locked |
|
Timecode |
DV data format |
SMPTE/EBU studio standard |
|
Advanced editing support |
No |
Yes |
|
Rugged? |
No |
Yes |
|
Price range [*] |
$500–$2,000 |
$6,000–$40,000 |
|
Lenses |
Built-in |
Interchangeable |
The significant distinctions between consumer and professional DV camcorders come down to technical specifications, usability features, price ranges, and lens options. So-called "prosumer" equipment offers a mixture of consumer and professional features and specifications. For more information, see the sidebar "The Prosumer Buzzword" later in this chapter.
DV Media: Mini DV and DVC
The DV technical standard specifies ¼-inch magnetic tape—but no particular size for the cassette the tape comes in. Currently, DV tape comes packaged in two cassette designs: Mini DV ( Figure 3.1 ) and Standard DVC.
)
Figure 3.1 The majority of today's DV camcorders, whether consumer or professional, use Mini DV cassettes.
Today, "Standard DVC" is something of a misnomer because Mini DV is by far the most popular DV tape format with a cassette measuring just 66 mm wide by 48 mm high by 12.2 mm thick, and capable of holding up to one hour of recorded material. (A 30-minute size is also available but is not as common.) The small size of Mini DV makes it easy to carry, and its price is economical: less than $10 each, or less than $5 each in bulk.
Mini DV cassettes are quite an improvement for pros who are used to handling book-sized media. Of course, there's a downside. Technology has now made it possible for you to lose a whole day's shooting in the pocket of the coat you just sent to the cleaners.
The DVC cassette is physically larger than the Mini DV, holds between 3 and 4.5 hours of material, and the tape stock is more durable than the tape used in a Mini DV cassette, which means it will withstand repeated shuttling and playback.
You may be perplexed to see Mini DV cassettes with "DVC" on the label, which is a reference to the tape width, not to the size of the cassette package. Most camcorders are designed to use one size cassette or the other, Mini DV or DVC; only a few professional units will accept both sizes.
Ultra-Compact Recording Media
You'll see some consumer DV camcorders equipped with other types of recording media besides cassettes:
- Memory Stick— Developed by Sony and known generically as a flash memory module, this solid-state wafer is about the size of a couple of postage stamps. Some camcorders use memory sticks as auxiliary recording media for holding still pictures. Depending on the size of the stick (4–128MB) and the capabilities of the camera, you might be able to also store a few seconds of video.
- MicroMV— Also developed by Sony, this is a tiny cassette about the size of a book of matches designed for camcorders no bigger than a pack of cigarettes. Although the cassette is 70 percent smaller physically than the Mini DV, it can still hold up to an hour of video.
-
8cm DVD—
Some camcorders can accept these recordable optical discs, which are about 3 inches in diameter (
Figure 3.2
). The camera can record up to 30 minutes of video directly on the 1.7 GB disc, which you can load directly into a DVD player or computer optical drive.
Figure 3.2 This consumer-model camcorder from Sony records onto an 8cm DVD that can be loaded directly into a home player. (Photo courtesy Sony Electronics Inc.)
)
However convenient these cameras and data formats might seem, don't use them for anything but home movies, email clips, and Webcasts. All of the ultra-compact formats capture video as MPEG-2, the same compressed files used to make DVD recordings. MPEG-2 is not as easily editable as uncompressed DV, and the results might look unprofessional. For more information on MPEG-2, see "Creating a DVD, Step by Step" in Chapter 12.
Other Output Options
Two other output options available with some camcorders deserve mention:
-
HDD—
Recording directly to a hard-disk drive (HDD) is an option with some professional DV and HD cameras (
Figure 3.3
). The main advantages are high capacity and reliability. Since the HDD units tend to be much bulkier than cassettes, this type of recording is mostly used in-studio. In fact, HDD is the only recording medium available for the Thomson Viper, an HD camera, because its 4:4:4 color space requires lots and lots of storage. (See the next section, "Color Space.")
Figure 3.3 An option for DVCAM professional-level cameras is an external hard drive, which can take the place of recording on multiple cassettes for long shooting sessions or events. (Photo courtesy Sony Electronics Inc.)
- Bluetooth— A type of wireless LAN used to link hardware units at distances of less than 35 feet, Bluetooth communication is a feature on some DV camcorders. It's handy for connecting cameras to computers for sending video directly out onto the Web. Remember, however, that Bluetooth offers relatively narrow bandwidth, about 2 Mbps, which makes it suitable only for home-movie-style applications.
)
Color Space
Consumer DV uses fewer data bits than professional DV to describe color, causing some hues to appear dull while others may seem too bright. Colors in professional DV are more lifelike. Consumer color space is defined as 4:1:1. Professional color space is defined as 4:2:2. Don't worry about what those numbers mean for now. (For more information, see "What Is Color Space and Why Is It Important?" in Appendix A.)
The most important practical impact of the different color spaces is that before you can broadcast a consumer DV program, you have to convert it to the professional spec. The conversion process isn't hard, but some people think that a converted video doesn't look as good as one that originated on professional DV in the first place.
Audio Sync
In professional DV, audio and video are absolutely in sync: a sound on the audio track is locked to the specific instant in the video frame during which it occurred. Editors rejoice at such perfection. In consumer DV, sync can drift by as much as 1/3 frame. This is rarely a big problem, but most professional editors doing meticulous sound edits prefer to work with professional DV.
Timecode
Timecode is a numeric index that identifies a specific location on a videotape by hour, minute, second, and frame (HH:MM:SS:FF). It's the editor's most reliable tool for quickly finding a desired take among hours of recordings.
Professional DV employs the same, strict SMPTE/EBU (Society of Motion Picture and Television Engineers/European Broadcast Union) timecode standard used in broadcasting, which can act as a control code for professional equipment like a studio video deck. Consumer DV camcorders generate timecode that is usable by desktop editing software but may not work with studio machines. After you've spent half an hour completing a sequence that would have taken five minutes with SMPTE timecode, you'll appreciate the difference.
These differences in timecode matter most to videographers who are working at studio-based production facilities. It could be downright embarrassing to proudly shove the cassette with your dailies into a deck in the edit bay, only to be scolded about not providing usable timecode. (For more information on timecode in editing, see "Selecting and Uploading Clips" in Chapter 10.)
Usability Features
Professional DV camcorders have a variety of features designed to speed the work for professional videographers and editors. (They are also designed to sell you the associated editing gear that interfaces with the camcorder, of course.) These conveniences include high-speed data connections that reduce upload times to the editing system, and electronic markers that permit you to flag just the good takes, to name just two. Professional gear is also more rugged than consumer gear and is less likely to be damaged by tough field conditions and the rigors of travel.
Price Range
Consumer DV camcorders range from $500 to $2,000, and thanks to those affordable prices, are very popular. These units are aimed at the home market where, sales executives believe, amateur videographers just want to point and shoot. To maximize ease of use, consumer camcorders are designed with relatively few manual controls and lots of automatic features. They're fine for shooting that special family event, or even a short training presentation, but if you have professional plans for your DV camcorder, you'll want more control over the results ( Figure 3.4 ).
)
Figure 3.4 Consumer-model DV camcorders usually have a built-in, nonremovable lens, flip-out viewfinder screen, and automatic features to promote point-and-shoot videography. The latest models are designed for portability and convenience, small enough to fit easily into a pocket, purse, or briefcase. (Photo courtesy Sony Electronics Inc.)
Professional DV camcorders start at around $6,000, including a zoom lens, and can run as much as $40,000, or more ( Figure 3.5 ). However, very few professional videographers actually buy their own camcorders. They either borrow them from a network equipment pool or rent them for the duration of a shoot. Renting doesn't mean they'll use whatever camcorder happens to be available. Pros always have strong opinions about the specific makes and models they prefer.
)
Figure 3.5 Professional DV camcorders like this one are tools of choice for shooting location news and other demanding field assignments. This model is the JVC GY-5000U, featured in the product comparison in this chapter. The base model has consumer color space; professional broadcast spec is available as an extra-cost option. (Photo courtesy JVC Professional Products Company.)
Prosumer DV camcorders, which range in price from $2,000 to $6,000, are becoming increasingly popular with serious, budget-conscious videographers—a group that includes independent filmmakers, corporate training and marketing departments, and every professional who wishes to own rather than rent his or her equipment ( Figure 3.6 ). In 2003, the first prosumer HD camcorder appeared on the market, JVC JY-HD10U ( Figure 3.7 ). It's a handheld model, featuring a single-chip CCD, and built-in lens, for a suggested list price of $3,995 (about a tenth what you'd have to spend for the lowest-priced professional model).
)
Figure 3.6 The Canon XL1S prosumer camcorder is popular with filmmakers thanks to features designed to support "film look" video. Although it has some professional features, it belongs to the prosumer category because of its consumer-format color space. This camera is featured in our comparison. (Photo courtesy Canon U.S.A., Inc.)
)
Figure 3.7 The JVC HD10U was the first prosumer camcorder to offer high-definition video and frame rates. (Photo courtesy JVC Professional Products Company.)
Lenses
Every serious moviemaker knows you should always use the best lenses you can afford. Typically, consumer camcorders come with built-in lenses, while professional units offer interchangeable lenses. The optics of interchangeable lenses are superior to built-in lenses, and they offer more precise controls over wider ranges of exposure and focal length. In fact, as far as pros are concerned, the most important reason for preferring one camcorder over another is the quality and variety of lenses available for that model.