Digital Camera

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Digital Cameras and WebCams

• Technology Advancement Group (TAG)
• Doug Baleshta May 10, 2004

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Sign of the Times
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A Short Course on Using Digital Cameras and Web
Cams

• Introduction
• What is a digital photograph
• Checklist
• Types of Cameras
• Image Sensors
• Image Storage
• Image Compression

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Contd

• Automatic Flash
• Lenses
• Automatic Settings
• Batteries
• Other Features- Panorama- Movie Mode
• Webcams- resolution- ethernet- wireless

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Introduction

• Cameras on display today
• What brands
• What features
• Memory
• Price

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What is a digital Photograph?

• Depends who you talk to!?
• Conversion of light intensity and colours into
  Digital bits
• Pixel series of dots on the screen (picture
  element)
• RGB 250,000 question on who wants to be a
  millionaire
• Bit Maps
• Additive Colour process

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Colour

• Using three primary colours through an additive
  process
• Varying intensity and combining gives us millions
  of colours

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Pixels

• What do they look like?

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Pixels

• Think of it as Jelly Beans (this picture)

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What is Contd

• Screen Resolution
• Digital Camera Resolution
• T.V. Resolution
• Printer/Scanner Resolution

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Screen Resolution

• 800 x 600 pixels and variations
• Optical vs Digital resolution

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Resolution
Element Resolution Total Pixels
Color TV (NTSC) 320 x 525 168,000
Human eye 11,000 x 11,000 120 million
35-mm slide   The "Economist" magazine says it has 20 million or more. CMOS Imaging News says 5 to 10 million depending on the film. Another source says about 80 million pixels. Robert Caspe at SoundVision states that color negative film has 1000 pixels per inch while color positive film has 2000 pixels per inch.
 
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Resolution

• Same Image, different size

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Resolution

• Stylus 300
• Adjustable Resolutions2048 x 1536 SHQ, JPEG2048
  x 1536 HQ, JPEG1600 x 1200 SQ1, JPEG1280 x 960
  SQ2, JPEG1024 x 768 SQ2, JPEG640 x 480 SQ2,
  JPEG320 x 240 _at_ 15fps QuickTime Motion JPEG160
  x 120 _at_ 15fps QuickTime Motion JPEG

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Size Isnt Everything

• Despite your Spam
• An 1800 x 1200 pixel image is approx an 8x10
• A 640 x 480 is close to a 5 x 4 picture
• Why use a 2400 x 1800 image when it wont even
  fit on the computer screen?

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Printer/Scanner Resolution

• Printer and scanner resolutions are usually
  specified by the number of dots per inch (dpi)
  that they print or scan. (Generally pixels per
  inch refer to the image and display screen and
  dots per inch refer to the printer and printed
  image.
• For comparison purposes, monitors use an average
  of 72 ppi to display text and images, ink-jet
  printers range up to 1700 dpi or so, and
  commercial typesetting machines range between
  1,000 and 2,400 dpi.

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Checklist

• Will you be shooting indoors? This will determine
  the quality of the flash you need
• Will you be photographing static scenes such as
  home interiors, or action shots such as sports?
  This will determine the best viewfinder and lens.
  
• In the Weather? You may need something robust.

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Checklist Contd

• Will you be photographing wide angle scenes such
  as landscapes and home interiors, telephoto
  scenes such as portraits, or close-ups such as
  stamps and coins?
• This will determine the focal length of the lens
  you need and whether you need a zoom lens,
  auxiliary lenses, or macro mode.

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Checklist Contd

• Are you a casual user, or a serious amateur or
  professional photographer? This will help you
  determine how many manual controls you'll want on
  the camera.
• Will you print the photos as snapshots,
  enlargements, or embed them in word documents? Or
  will you publish the images on a Web page, e-mail
  them to others, or include them in a
  presentation? This will determine the best
  resolution for your situation.

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Checklist Contd

• What imaging software do you need?
• What comes with the camera?
• Do you need more or less?
• Photoshop may be overkill

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Types of Cameras

• Regardless of how digital cameras look, the
  market for them is roughly divided into three
  tiers with blurry lines separating cameras based
  mainly by image resolution, features, and of
  course, price.
• At the low end are the fully automatic point and
  shoot cameras with resolutions of 3 to 4 million
  pixels or so and prices below 500.

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Types of Cameras contd

• At the next level are those having 4 to 5 million
  pixels in their image sensors. Costing less than
  1000 these cameras also give you lots of
  creative control.
• 1000 - 2000 for amateur and professional
  photographers. These cameras have 6-12 million
  pixels and many are based on 35mm designs and
  interchangeable lenses. These cameras have the
  highest resolution, most features, and highest
  prices.

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Cameras Digital Movie

• With the latest digital video cameras, you don't
  have to digitize frames because they are captured
  in a digital format. - But
• Some digital still cameras are capable of
  capturing short video sequences and some digital
  video cameras can also capture still images.
• Resolution is higher with digital cameras

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Cameras Contd- Cell Phones, Watches
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Sensors

• Two flavours, CCD (Charge Couple Device -) and
  CMOS (Complementary Metal-Oxide Semiconductor)

This photo shows the pixels on an image sensor
greatly enlarged. Courtesy of IBM.
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Sensors contd

• The Canon EOS 10D is a high-end digital SLR from
  a major manufacturer that uses a CMOS image
  sensor. The Canon EOS 1Ds, used by professionals,
  also uses a CMOS sensor and has 11.1 million
  pixels. Courtesy of Canon.

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Image Storage

• Fixed limited size, limited amount of pictures
• Removable lots of flavours- some are specific
  to your camera Olympus xD allows panoramic
  pictures- Compact Flash - CompactFlash cards and
  slots that are 3.3 mm thick are called
  CompactFlash (abbreviated CF) or CompactFlash
  Type I (CF-I). - CompactFlash cards and slots
  that are 5mm thick are called CompactFlash Type
  II (CF-II). 

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Image Storage contd

• Sony memory sticks - shaped something like a
  stick of gum, are currently used mainly in Sony
  products.

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Image Storage Contd

• So how many pictures can I store?
• Well, that depends
• Image format (JPEG, TIFF), Image Size (1800x1200
  or 640x480) and Flash Card size. (Ex - Olympus
  128megs 160 full size jpeg images).

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Image Storage

• Stylus 300
• Number of Storable PhotosWith 16MB xD-Picture
  CardSHQ, HQ 2048 x 1536 6, 20 shotsSQ1 1600
  x 1200 24 shotsSQ2 1280 x 960 38 shotsSQ2
  1024 x 768 58 shotsSQ2 640 x 480 99 shotsHQ
  Movie 320 x 240 15 fps 16 sec. max per movieSQ
  Movie 160 x 120 15 fps 40 sec. max per movie

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Image Storage Etc

• HP integrates their printers with their cameras
  flash memory, infrared, docking station.

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Image Compression

• Lossless vs Lossy
• Lossless compression uncompresses an image so its
  quality matches the original sourcenothing is
  lost.
• For this reason, lossless compression is used
  mainly where detail is extremely important, as it
  is when planning to make large prints. Lossless
  compression is offered by some digital cameras in
  the form of TIFF and RAW file formats

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Image Compression contd

• Lossy compression.
• Because lossless compression isnt practical in
  many cases, all popular digital cameras offer a
  lossy compression.
• This process degrades images to some degree and
  the more they're compressed, the more degraded
  they become. In many situations, such as posting
  images on the Web or making small to medium sized
  prints, the image degradation isn't obvious.

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Image Compression contd

• Jpeg Variable Compression dramatic reduction
  in file size

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Flash

• Flash Range?
• Flash Working RangeWide 8" 8.5' (.2 m 2.5
  m), Tele 8" 6.0' (.2 m 1.8 m) (Olympus
  Stylus 300)
• Red-Eye Reduction
• Automatic Mode

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Flash contd

• Fill mode flashes even in bright conditions

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Lenses

• Focal Length as used on 35 mm cameras (50 mms
  are usual, 35 mm are wide angle, 65 mm are
  telephoto)

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Lenses contd

• Olympus Stylus 300 - Lens Olympus aspherical
  glass 3x zoom lens 5.8 17.4mm (35 105mm
  equivalent in 35mm photography), 5 lenses in 3
  groups
• Interchangeable with 35mm? depends
• Optical Zoom is superior to Digital Zoom
• Glass is better than plastic

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Lenses - Aperture

• The larger the Aperture, the less light required
• The Stylus has an aperture range of F3.1W/F5.2 T
• F1.8 would let more light in, can be used in
  darker conditions

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Automatic Settings

• It take the digital camera some time to calculate
  focus, colour balance, shutter speed, F settings
• Remember this when taking the picture
• Moveable focus

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Automatic Setting Contd

• Different lighting gives different results
• Incandescent gives warm tones

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Automatic Settings contd

• Fluorescent washes out colours

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Automatic Settings

• Underwater pictures rapidly loose the Reds and
  Yellows the deeper you go - the longer wave
  length light gets absorbed (warm colours).
• Require additional lighting to fill in. Filters
  can also work (Red for example).

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Batteries

• Lithium Ion Best, most expensive, fast
  charging, no memory last 2-3 years
• NiMh Nickel Metal Hydride good value, 400
  charges
• NiCad not usual for digital cameras
• Sizes proprietary or available off the shelf?

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Batteries - rating

• Batteries are rated by voltage and milliamp hours
  (mAH). Most AA-sized NiMH batteries are rated up
  to 2100 mAH. A 2100 mAH battery can deliver 2,100
  milliamps (mA) for one hour (H). Generally
  speaking, the higher the rating, the more
  pictures you can take.

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Batteries contd

• Storage cool dry place when not in use
• Travelling get them charged first you may
  have to demonstrate your equipment at security
• Europe/Asia 220 Volt need a
  converter/inverter?

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Other Features

• Panorama Mode ability to link pictures together
  to create a seamless imageUp to 10 frames
  stitchable with CAMEDIA Master software when
  using Olympus brand xD-Picture Card
• Sequence - 1 frames per second, more than 4
  frames in HQ mode.

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Other Features contd

• For 16 mb card. HQ Movie 320 x 240 15 fps 16
  sec. max per movieSQ Movie 160 x 120 15 fps 40
  sec. max per movie Stylus 300 no sound
  however.
• Flash Variation Timed, red eye, night-time, low
  light

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Other Features contd

• Viewing RCA video out?
• USB file transfer
• Date/Time stamp
• Image Preview use power, use viewfinder if
  possible

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WebCams

• Cheap- 50
• USB Universal Serial Bus
• Sometimes include a microphone
• Lower Resolution
• Good for video conferencing
• Resolution typically 380 lines, smaller than
  regular TV

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Web Cams

• Ethernet/wireless WebCAM- connect to the
  internet- allows remote control through the
  internet- can automatically take a picture when
  detecting movement
• IR WebCams no light conditions.

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Whew!!!

• A little knowledge is dangerous
• Callling all Carbon Units - Go forth and use your
  technology

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Credits

• http//www.shortcourses.com/index.htm
• http//www.olympus.com
• Technology Advancement Group Natasha Scott,
  Martin Voelkening

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Resources

• http//www.dpreview.com/ - Website that reviews
  digital cameras
• www.gimp.org open source imaging software
• http//www.imaging-resource.com/ - imaging
  resources website
• greenbatteries.com. Battery information

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Thanks!