Video Helical Scan Video Helical ?
Transcript of Video Helical Scan Video Helical ?
Video
Helical Scan Video
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Helical Scan Video
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Spiral
Tracks of 1/2” Helical Scan Video
Audio (2)VideoControl
Helical Scan Video
SupplyReel
Take-upReel
TiltedVideo Drum
Audio & control track erase head
Audio & control track record head
Full erase head
Helical Scan Video
TiltedVideo Drum
Video Head
Side view
Top view
Video Tape
VHS VHS-C
8mm video• official name: Video8• mainly used with video cameras• small tape size
miniDV• Digital Video (DV) - 1996 • MiniDV - standard for consumer and semiprofessional video
production• Features include:
– intraframe compression for uncomplicated editing– a standard interface for transfer to non-linear editing systems
(IEEE 1394/FireWire)– good video quality, especially compared to earlier consumer
analog formats such as 8mm, Hi-8 and VHS-C.
• variants on the DV standard– DVCAM(Sony)– DVCPRO ( Panasonic) – high-definition version called
HDV, with MPEG-2 for compression
digital8• Sony - late 1990s.• uses conventional analog Video Hi8 tapes, but
records the video signal in digital form using the DV codec.
• excellent video and audio quality• Sony is the only company that produces D8
camcorders.
Video Format Advantages
Format: VHS VHS-C 8mm miniDV Digital8
Advantages in the field
Large enough to feel like pro gear
Inexpensive Inexpensive Most common digital format - high quality
Also high quality, with added advantage that the tapes are inexpensive (ordinary 8mm).
Advantages in an editing environment
Tapes can be used with any VCR, so you don't need to tie up your camcorder when capturing
With an adapter, tapes can be used in any VCR (see VHS)
none High quality, digital interface gives direct control over camcorder
see miniDV. Sony Digital8 cameras will also play back and digitize analog 8mm video tapes
Video Format Disadvantages
Format: VHS VHS-C 8mm miniDV Digital8
Dis-advantages
Quality not great
Lowest quality. Quality not great, and unlike VHS/VHS-C, you must tie up your camcorder for capture.
Somewhat more expensive. Tapes are also expensive. Although miniDV VCRs are available, they're very expensive, and so you must tie up your camcorder for capture.
Format is unique to Sony Digital8 camcorders - no other brand of camcorder uses this format or will play Digital8 tapes.
• Camera, recorder, playback all in one• Portable - compact, light, easy to handle• Immediate playback• Good to excellent quality• Can use in low light levels• Affordable• Attach to VCR for copying• Attach to TV for playback
Advantages of a camcorder
• Cost
Disadvantages of a camcorder
• Close-up• Movement
– Pan– Tilt– Truck– Dolly
• Lens characteristics– Zoom– Telephoto– Wide angle– F-stops
Camera operations• Composition• Camera angle• Optical & mechanical
effects• Electronic effects
• QuickTime• iMovie (Mac)• Windows Media 9 (WMV9)• Media 100• Video Toaster
Desktop video production
• Portable (VCR, Videodisc, DVD)• Broadcast (Commercial, Public)• Satellite• Microwave• Closed circuit • CATV
Television Distribution Systems
Broadcast
Satellite
Microwave
Closed-circuit system
CATV
• One-way video, two-way audio• Two-way video (PictureTel)
Video Conferencing
Two-way Video Teleconferencing
• sequence of "moving images" that are sent in compressed form over the Internet and displayed by the viewer as they arrive.
• streaming media is streaming video with sound • media is sent in a continuous stream and is played
as it arrives • user needs a player, which is a special program
that uncompresses and sends video data to the display and audio data to speakers
• a player can be either an integral part of a browser or downloaded from the software maker's Web site
Streaming Video