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Do you know the basics about video before you
convert your home movies to DVD? Below is a
quick primer to some of the basic terms. Video began in the late
1830s, when it was learned that a series of still images shown
in rapid succession produces the illusion of motion. By the 1920s,
silent film added sound, and soon after, video technology was
developed for cathode ray tube television.
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Video
tape conversion - where did it begin? |
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"Video" is the electronic process of
capturing, recording, processing, storing, transmitting, and
reconstructing a sequence of still images. It is delivered in
either analog or digital formats.
Digital is a signal that consists of only two states: a pulse
or absence of a pulse. It is delivered in binary numbers: 1 and
0. Digital video has many forms, such as DVD, Mini DV tape, and
online video such as Quicktime.
By comparison, analog is any variable signal that is continuous
in time and amplitude. This can result in noise or variation
in the signal. Analog video commonly refers to video tapes, such
as VHS, Betamax, and Video 8.
When we transfer videotape, we are converting an analog signal
to digital. This process involves a variety of settings and needs
to be done correctly for accurate preservation. Our customers
have found our transfer process, however, to be true to the original
analog video. We are focused on preserving the quality when we
record tape to DVD. |
Video
transfer to DVD, in NTSC or PAL |
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Two primary video formats are used throughout the world: NTSC
(dominant in North America and Japan) and PAL (dominant in
Europe and Australia). A third format, SECAM, is used in France,
Russia, and parts of Africa. The chart at the right shows NTSC
countries in green, PAL countries in yellow, and SECAM countries
in orange.
The formats differ from each other in two main respects: line
resolution and frame rate. NTSC video has a resolution of 480
horizontal lines and a frame rate of 29.97 frames per second.
PAL has a resolution of 576 horizontal lines and a frame rate
of 25 frames per second. Because of this, PAL possesses a slightly
sharper picture and a frame rate closer to film.
NTSC and PAL standards apply to all video electronics: TVs,
VCRs, and DVD players. PAL video tapes cannot play on NTSC VCRs
and TVs, and vice versa.
To further complicate matters, the developers of DVD technology
assigned DVD regions to the world as well. NTSC DVDs in the United
States are Region 1, and PAL DVDs in the United Kingdom are Region
2. DVD players sold in each country are programmed to only play
discs of their own region code. See our DVD
Video Transfer page for specific information about the DVD
format. |
Home
movies to DVD - about aspect ratios |
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The size of an image – for video
transfer to DVD as well – is measured in
horizontal scan lines and vertical lines of resolution for
analog video. During the video
convert process, this is altered to pixels.
NTSC has a digital picture size of 720 pixels by 480 pixels.
In analog terms, that equates to 480 lines, although this measurement
depends on the signal source. For example, VHS
to DVD only produces about 250 lines of resolution, while
S-VHS and Hi8 video technology reached a threshold of 420 lines.
There is also aspect ratio, which is the width/height dimension
of the video screen. The screen aspect ratio of a traditional
television screen is 4:3. High definition televisions use an
aspect ratio of 16:9. |
Trust your video tape conversion to
Timeless DVD! |
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