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Chapter 2: Capture 10
Digital Video Capture
The MiniDV and DVCAM (DV25 format) are popular high-quality digital formats that
integrate well with computers.
The DV format offers higher image quality and resolution than Hi8, S-VHS and VHS. It is a
digital format, so DV does not suffer from generation loss — a copy of a DV tape is identical to
the original. DV equipment is reasonably priced for its level of quality. These attributes have
made DV the new format of choice for many Web and video professionals.
Some DV cameras offer a progressive scan feature. This records each frame as a single non-
interlaced image instead of two separate interlaced fields. Progressive scan source material
may not play as smoothly on a television monitor as interlaced material, but it is superior for
streaming because it contains no interlacing artifacts. You should look for this feature when
buying a DV camera and use it when creating streaming content.
There are a wide range of DV cameras available. Lower-priced cameras generally have lower
image quality and fewer features. Higher-quality DV cameras usually have higher-quality
optics, image stabilization and many other features to deliver superior image quality.
Analog Capture
Analog consumer formats (Hi8, S-VHS, and VHS) produce noisier signals and lower-resolution
video than DV and the professional formats. Hi8 and S-VHS are superior to VHS. You need
either an analog-to-DV converter or an analog-compatible video capture system to work with
them on the computer.
If you are using an analog video system, you can do several things to improve the quality of
the captured video.
To get the highest-quality results, capture analog video at full-screen resolution — 640x480
(NTSC) or 720x480 (DV) — depending on the native resolution of the source. Even if you intend
to deliver smaller final movies, a full-screen capture generally gives better results for a number
of reasons. For example, capturing at full screen and scaling down the image tends to reduce
video noise and results in a smoother-looking image, which encodes better.
Full-screen capture is required to use Cleaner de-interlacing features. If the original source was
shot on film and transferred to video tape, capturing at full-screen resolution and full frame
rate is required to use Intelecine, which removes 3:2 pulldown frames and returns the material
to its original 24 fps.
Most captured video has black edges around the perimeter. This is called overscan or edge
blanking. To deliver professional results, you must remove these edges. Starting from a larger
image enables you to crop and then scale the image down. If you only capture at the final size
that you wish to deliver the video, removing edge noise requires you to crop and then scale up
the video, which degrades image quality.