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
Contd Automatic Flash Lenses Automatic Settings Batteries Other Features - Panorama - Movie Mode Webcams - resolution - ethernet - wireless
Introduction Cameras 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 Think of it as Jelly Beans (this picture)
What is… Contd Screen Resolution Digital Camera Resolution T.V. Resolution Printer/Scanner Resolution
Screen Resolution 800 x 600 pixels and variations Optical vs Digital resolution
Resolution ElementResolutionTotal Pixels Color TV (NTSC)320 x 525168,000 Human eye11,000 x 11,000120 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 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 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?
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 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.
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.
Checklist Contd 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 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.
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
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 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.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 contd Sony memory sticks - shaped something like a stick of gum, are currently used mainly in Sony products.
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).
Image Storage Stylus 300 Number of Storable PhotosWith 16MB xD- Picture 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 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.
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 contd Fill mode – flashes even in bright conditions
Lenses Focal Length – as used on 35 mm cameras (50 mms are usual, 35 mm are wide angle, 65 mm are telephoto)
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
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 Contd Different lighting gives different results Incandescent – gives warm tones
Automatic Settings – contd 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 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?
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 contd 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, night- time, low light
Other Features contd Viewing – RCA video out? USB file transfer Date/Time stamp Image Preview – use power, use viewfinder if possible
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
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 camerashttp://www.dpreview.com/ www.gimp.org – open source imaging softwarewww.gimp.org http://www.imaging-resource.com/ - imaging resources websitehttp://www.imaging-resource.com/ greenbatteries.com. Battery informationgreenbatteries.com