Digital Video

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Digital Video
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Analogue Video

• VHS - about 1980 - very large, accepted full size
  VHS cassette
• S-VHS - better quality, special tapes, expensive
• 8 mm - very small cassette, and so camera is
  small - about 15 cms. Special tape and so camera
  became the VCR.
• Hi-8 - higher quality electronics and tape.
  Bridge between consumer and professional -
  prosumer

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Problems with analogue

• Each time tape is copied, there is a loss in
  quality
• Limited life span - cannot be preserved by
  copying to a fresh tape.

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Advantages of digital

• Smaller - size is basically governed by the size
  of the cassette and digital is smallest
• Very high quality - much higher resolution than
  other formats
• Very good sound - higher than CD (48 kHz cf. 44.1
  kHz)
• Can make copies of copies
• DV is forever.

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Disadvantages of digital

• Cassettes only hold 1 hour of video
• And they are expensive

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Uses of DV in the classroom

• Instructional video
• Analysis - drama, sport, etc.
• As a form of assessment
• Interviews
• Field trips, excursions, etc.
• As part of the learning process

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Buying a digital video

• Big price range
• Cameras can have a host of features
• But are they all needed?

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Connecting to a computer

• Firewire
• IEEE-1394
• iLink
• DV In/Out
• DV Terminal

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Analogue inputs

• Used to transport material to analogue devices
• VCRs
• Older camcorders, etc.

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Sony Digital8 camcorder

• Uses Hi8 tapes

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Quality - CCDs

• CCD - charge couple device
• High quality have 3 (red, green blue
• Larger and more expensive

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LCD viewfinder

• LDC - liquid crystal display.
• Usually has in-built speaker
• Can be used to view video

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Electronic image stabiliser (EIS)

• Most DV cameras are hand held
• Excessive movement can make video look amateurish
• EIS systems are given different names by various
  manufacturers.

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Optical zoom

• DV cameras often have an Optical and digital zoom
• 12X/300X Zoom
• When optical limit is reached, digital zoom
  starts, but just enlarges pixels.

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Manual override

• Good quality cameras should allow you to override
  automatic functions

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Battery readout

• Memory effect is a thing of the past
• Lithium-ion batteries eliminate this problem
• Some batteries even tell the camera how much
  power is left

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Remote control

• Allows you to use the camera remotely
• Also gives control when camera is connected to a
  TV

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Night-vision mode

• Offered by some Sony Cameras
• Enable filming in complete darkness
• Uses infrared transmitter
• Objects only 3 meters away.

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Still camera mode

• Most cameras have a photomode
• Resolution is only 72 dpi
• Much better to use image capture in iMovie

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Titles, fades, etc.

• Cameras can have the ability to generate titles,
  transitions between shots, and so on.
• Better to use those built into the software such
  as iMovie

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Which brand to buy

• Virtually all manufacturers have adopted DV
  format
• Sony and Canon get best marks for Firewire
• Other companies can use none standard versions of
  Firewire messages - use their own software (but
  pay for it).