Specifications

14
A Digital Video Primer
• Sony Digital Betacam, DigiBeta, or Betacam SX, IMX, and HDCAM: ese formats are the choices
of high-end broadcast professionals. e formats provide superior image quality, and the high-
end equipment required to work in these formats is proportionately costly. e video interface
is SDI or HD-SDI, which provides an uncompressed bitstream at 270 Mbps for Digi-Beta, and
up to 1.5 Gbps for HDCAM.
• Sony XDCAM (SD and HD) and Panasonic P2: ese DV variations use the same formats as others
(DV25 or DV50), without tape. e P2 camcorders record to solid-state memory cards, and the
XDCAMs record to Professional Disc optical recording media. e biggest advantage of recording
to a disc or memory card is that you can skip the capture process entirely and perform nonlinear
editing directly from the source media—a real time-saver for broadcast news. ere is little
doubt that the tapeless solutions are the future of recording media.
Camcorder basics
A video camera is called a camcorder when it includes a recording device, such as a video cas-
sette recorder (VCR) or optical disc recorder. Most camcorders also include a microphone and
other features, such as lighting, that make them a complete production unit in one portable
package. e line between consumer and professional can be somewhat blurry, but understanding
the basics of camcorder technology will help you make the best decisions when purchasing or
selecting a camcorder for production.
The better the lens, the better the quality. Camcorders are similar to still cameras, in that a better
lens (and that usually means a more expensive one) produces clearer, sharper images. Lower-end,
consumer-targeted DV camcorders have permanent lenses that are typically not of the same
high quality as professional video camcorder lenses. If you want the exibility of interchangeable
lenses, you’ll probably have to use a professional-grade camcorder.
Optical or digital zoom. Whether xed or interchangeable, most camcorders come with zoom
lenses, which allow you to achieve more of a close-up view of your subject without actually mov-
ing the camera closer. But you’ll want to know if the camcorder lens you’re getting oers true
optical zoom, or only digital zoom. For true optical zoom, the lens physically varies the focal
length, which is measured in millimeters. e longer the focal length, the closer you can get to
your subject. An optical zoom gives you the highest-quality picture.
Digital zoom, on the other hand, is not really a zoom feature at all. It’s more of a cropping feature
that enlarges a small area of the image to simulate a close-up. As the image is enlarged, so are the
pixels, so what you get is degraded quality. If you want clarity, use optical zoom only.
One CCD or three? CCD stands for charge-coupled device. CCDs detect the light coming through
the lens into a camcorder and convert it into electrical signals. e factors that determine the
quality of the resulting images are: the number of CCDs, size of each CCD chip, number of active
pixel elements on each chip, and the quality of CCD electronics. Camcorders with one CCD rely
on a single chip to capture light from all three primary colors (red, green, and blue); those with
three CCDs dedicate a chip to each color and are, therefore, able to produce higher-quality images.
Expect a signicant dierence in price between 1-CCD and 3-CCD camcorders.
What about lux? A CCD’s responsiveness to light also impacts video quality. Lux is a measure
of illumination (reected light) used to specify a camcorder’s low light responsiveness limit and
the amount of light recommended for achieving good quality video. e more light a camcorder
requires, the higher its lux rating. Some camcorders have infrared (IR) capabilities that will
record in 0 lux situations (for example, at night). You may also want to note a camcorder’s signal-
to-noise ratio. A camcorder may be able to achieve a low lux rating by producing a very noisy
picture. A higher signal-to-noise ratio produces better quality images in low light conditions,
while a low ratio records images that appear grainy or smudged.
OK 1-1/4” CCD = 1 CCD with a small
(1/4”) chip
Good 1-1/3” CCD = 1 CCD with a large
(1/3”) chip
Very good 1-2/3” CCD = 1 CCD w/ an extra
large (2/3”) chip
Excellent 3-1/4” CCD = 3 CCDs with small
chips
Best 1-1/3” CCD = 3 CCDs with large chips
Image quality based on CCD setup