Transcript Digital Camera’s and WebCams

Digital Camera’s
and WebCams
Technology Advancement Group
(TAG)
Doug Baleshta – May 10, 2004
Sign of the Times
A Short Course on Using Digital
Cameras and Web Cams
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Introduction
What is a digital photograph
Checklist
Types of Cameras
Image Sensors
Image Storage
Image Compression
Cont’d
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Automatic Flash
Lenses
Automatic Settings
Batteries
Other Features
- Panorama
- Movie Mode
• Webcams
- resolution
- ethernet
- wireless
Introduction
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Camera’s on display today
What brands
What features
Memory
Price
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
Colour
• Using three primary colours through an additive
process
• Varying intensity and combining gives us millions
of colours
Pixels
• What do they look like?
Pixels
• Think of it as Jelly Beans (this picture)
What is… Cont’d
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Screen Resolution
Digital Camera Resolution
T.V. Resolution
Printer/Scanner Resolution
Screen Resolution
• 800 x 600 pixels and variations
• Optical vs Digital resolution
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.
Resolution
• Same Image, different size
Resolution
• Stylus 300:
• Adjustable Resolutions2048 x 1536 SHQ, JPEG
2048 x 1536 HQ, JPEG
1600 x 1200 SQ1, JPEG
1280 x 960 SQ2, JPEG
1024 x 768 SQ2, JPEG
640 x 480 SQ2, JPEG
320 x 240 @ 15fps QuickTime Motion JPEG
160 x 120 @ 15fps QuickTime Motion JPEG
Size Isn’t 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
won’t even fit on the computer screen?
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.
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.
Checklist Cont’d
• 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.
Checklist Cont’d
• 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.
Checklist Cont’d
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What imaging software do you need?
What comes with the camera?
Do you need more or less?
Photoshop may be overkill
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.
Types of Cameras cont’d
• 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.
Camera’s – 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
Camera’s Cont’d
- Cell Phones,
Watches
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.
Sensors cont’d
• 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.
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).
Image Storage cont’d
• Sony memory sticks - shaped something
like a stick of gum, are currently used
mainly in Sony products.
Image Storage Cont’d
• 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 128meg’s – 160 full
size jpeg images).
Image Storage
• Stylus 300
• Number of Storable PhotosWith 16MB xDPicture Card:
SHQ, HQ: 2048 x 1536: 6, 20 shots
SQ1: 1600 x 1200: 24 shots
SQ2: 1280 x 960: 38 shots
SQ2: 1024 x 768: 58 shots
SQ2: 640 x 480: 99 shots
HQ Movie: 320 x 240 15 fps: 16 sec. max per
movie
SQ Movie: 160 x 120 15 fps: 40 sec. max per
movie
Image Storage Etc
• HP integrates their printers with their
cameras – flash memory, infrared, docking
station.
Image Compression
• Lossless vs Lossy
• Lossless compression uncompresses an image
so its quality matches the original source—
nothing 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
Image Compression cont’d
• Lossy compression.
• Because lossless compression isn’t 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.
Image Compression cont’d
• Jpeg – Variable Compression – dramatic
reduction in file size
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
Flash cont’d
• Fill mode – flashes even in bright
conditions
Lenses
• Focal Length – as used on 35 mm
cameras (50 mm’s are usual, 35 mm are
wide angle, 65 mm are telephoto)
Lenses cont’d
• 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
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
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
Automatic Setting Cont’d
• Different lighting gives different results
• Incandescent – gives warm tones
Automatic Settings – cont’d
• Fluorescent washes out colours
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).
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?
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.
Batteries cont’d
• 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?
Other Features
• Panorama Mode – ability to link pictures
together to create a seamless image:
Up 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.
Other Features cont’d
• For 16 mb card. HQ Movie: 320 x 240 15
fps: 16 sec. max per movie
SQ Movie: 160 x 120 15 fps: 40 sec. max
per movie – Stylus 300 – no sound
however.
• Flash Variation – Timed, red eye, nighttime, low light
Other Features cont’d
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Viewing – RCA video out?
USB file transfer
Date/Time stamp
Image Preview – use power, use
viewfinder if possible
WebCams
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Cheap- $50
USB – Universal Serial Bus
Sometimes include a microphone
Lower Resolution
Good for video conferencing
Resolution – typically 380 lines, smaller
than regular TV
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.
Whew!!!
• A little knowledge is dangerous
• Callling all Carbon Units - Go forth and
use your technology
Credits
• http://www.shortcourses.com/index.htm
• http://www.olympus.com
• Technology Advancement Group –
Natasha Scott, Martin Voelkening
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
Thanks!