Practical DV FilmMaking

its own specification for how many lines a television signal must produce and how many frames per second it should have. In Europe and Australia, the standard is PAL (Phase Alternating Line), which operates on a high level of quality in terms of pixels on screen but slightly lower frame rate. In America, the standard is called NTSC (National Television Systems Committee) and has a lower number of pixels on the screen, but operates on a faster frame rate of 29.9 (often rounded up to 30). A different system called SECAM (sequential couleur avec memoire, or sequential colour with memory) is used in parts of eastern Europe, some African countries, parts of South America and the former states of the USSR. SECAM is closer to PAL than NTSC, using the same bandwidth as PAL but transmitting colour information sequentially. Countries using SECAM can play PAL videos or DVDs more easily than NTSC.

To complicate matters, there is also a version of PAL known as PAL 60, leaving the old PAL to be known as PAL 50. The new version is intended to help address the problems of NTSC users viewing

Countries using PAL

Countries using NTSC

Countries using Secam

Argentina

Caribbean islands

Albania

Algeria

Canada

Bulgaria

Andorra

Chile

Colombia

Australia

El Salvador

Czech Republic

Austria

Guatemala

Egypt

Belgium

Japan

Former USSR

Brazil

South Korea

France

China

Mexico

Iran

Denmark

Peru

Poland

Germany

Puerto Rico

Romania

Greece

USA

Zaire

Finland

Venezuela

Hong Kong

Iceland

India

Indonesia

Ireland

Israel

Italy

Kenya

Malaysia

Netherlands

New Zealand

Norway

Portugal

South Africa

Spain

Sweden

Switzerland

Turkey

United Kingdom

Zimbabwe

Figure 2.3 Table of international TV standards.

PAL movies. NTSC uses a frame rate of 30 frames per second while PAL uses 25, but the new PAL also uses 30.

Pixels

The number of pixels, or dots on the screen, is determined by how many vertical and horizontal lines the signal has. The NTSC ratio of 640 X 480 has roughly 307 000 pixels, whereas PAL has 720 X 560, giving it the edge with over 400 000. This will lead to greater clarity and sharpness in PAL, but it suf­fers when it comes to frame rate.

Frame rate

Frame rate (the number of individual pictures that have to make up a single second of tape) affects smoothness of movement. A film shot on fewer frames per second (fps) will look more jerky than one on higher fps. There are ways of easily transferring a recording so that a programme made for American TV (NTSC) will play on British or Australian TV (PAL), even though they use different frame rates.

Format

Advantages

Disadvantages

Suitable for:

HDV

The highest quality available for filmmakers. It records 720 x 1080 (interlaced) video on tape and is now being targeted at the filmmaker and semi-professional. All camcorders may use this format one day.

For filmmakers, the problem is compression, with images being so large that they need extensive reduction before recording onto tape. Editing can also be problematic - settings need to be adjusted. File sizes, however, are not that big, when compared to the size of the data they carry. But this is the problem: compression is too massive - for now.

All types of filmmaking. HDV camcorders are reasonably priced and within range of the low-budget filmmaker.

Digi-Beta

Successor to Betacam, it uses ^2-inch cassettes, recording on a 2:1 compression ratio. Good for ENG (Electronic News Gathering) due to the high broadcast quality.

Expensive tapes for expensive cameras.

Broadcast work; documentaries.

DVCAM/DVC Pro

DVC Pro is Panasonic's version of DV, designed for professionals with double tape recording speed for better quality and fewer drop-outs. DVCAM is a similar version put out by Sony, but slightly lower in terms of quality than the DVC Pro. Both are almost broadcast standard.

Both are being superseded by HDV.

Ideal for filmmaking. Location and news gathering is also suitable. The near-broadcast quality means that most cable channels will accept work on these formats.

Betacam SP

(analog)

An improvement on the broadcast standard - until DV - introduced in 1986. Was hugely popular in broadcasting, with many cameras still being used in this format in smaller networks.

Large cassettes: 14 x 25 cm for a 90-minute tape. Smaller cassettes are often used on location, but these are only 30 minutes long.

Used for programme-making in cable and local television. Good for student-level broadcast training.

Mini-DV (digital)

Most widespread of all DV formats in the domestic market. Tapes are small and long-lasting; camcorders record at 500 lines, giving high quality images.

Compression ratio is good but still far under that needed for broadcast standards.

It depends on the camera. If you use a single-chip camera it is not suitable for filmmaking if you intend to submit to festivals or cable slots. However, a three-chip camera will record excellent images to tape, which will be acceptable to many broadcasters, especially cable, and will pass festival panels.

DVD-RAM (digital)

Arrived in the middle of 2001 to much fanfare. Images are recorded on disc, so can be randomly accessed (no rewinding needed). Also allows basic editing by moving around footage.

Heavy compression means you aren't editing with master footage, having already been compressed with MPEG-2. Discs don't play in all manufacturers' players. Problems with image pixellation when panning.

Although the quality of the images is good (mini-DV level), the format is unsuitable for filmmaking as the footage is not captured via FireWire cable but is taken from a disc.You cannot output to tape, which means you can only make DVD copies, not tape masters.

Digital 8 (digital)

Sony's upgrading of its Hi-8 format. It is backwards compatible with analog 8 mm formats.

Digital 8 cameras tend to be bigger and heavier than similar DV cameras.

Useful if you have a lot of analog footage on Hi-8 tape and need to archive it or convert to digital. But it is probably better suited to domestic home movies than filmmaking.

MicroMV (digital)

Smallest cameras on the market, capturing 60 minutes of footage with MPEG-2 compression on tape. Tapes are 70% smaller than mini-DV tapes. Footage takes up much less space on your PC as it is so highly compressed.

Very few editing software programs can deal with it. Compression rate is high, affecting quality.

Useful for work where lightweight camera is necessary (for instance, in mountain climbing shots). Not suitable for filmmaking, if possible.

VHS/S-VHS

Cameras for these formats are exceptionally cheap, especially in the second-hand market.

S-VHS is the upgrade to VHS, but both are dying out under the relentless march of DV.

Completely unsuitable for filmmaking. Useful for educational settings, with children, but even here the better camera is the small hard-drive recorder, such as the Bluemovie camera.

Figure 2.4 Video formats explained.

Timecode

Another, more complicated factor in frame rate is timecode. In terms of frame rate, timecode is more of a headache with NTSC than with PAL. PAL, with its nice, easily divisible numbers (25 goes into 100 neatly), presents no problem for accurate timecode. The 29.9 fps of NTSC, however, needs to operate with something called 'drop-frame timecode', in which certain frame numbers - not your actual hard-won frames themselves from the footage - are dropped out to keep everything in round numbers. It gets rid of two frames every minute but skips every tenth minute. Thankfully, you no longer have to worry about drop-frame timecode as many edit programs offer you the chance to work in this method. But it is essential if you intend to work in productions of 60 minutes or more, as you would end up with an error rate of 3.6 seconds every hour. If you are intending to sell broadcast material to zones with other broadcast standards, check what they use and edit the movie with this in mind.

The Crunch

• You need manual override on your camera

• Get a three-CCD-chip camera if you can

• Understand the way cameras record so you can use them creatively

• OK, maybe you don't want to know all this technical stuff, but make sure someone in your next crew does.