David E. Pitts Digital Cameras 101 Digital Cameras by David E. Pitts March 27, 2012 Copyright 2012

David E. Pitts Digital Cameras Types of Digital Cameras Consumer - Point and shoot ($100 - $400) Prosumer - Serious amateur photographers (≈ $800) Professional - Large expensive cameras (≥ $1,000)

David E. Pitts Digital Cameras 101 Instead of film an array of silicon chips is used. Typical 5 megapixel sensor is a 5 x 7 mm silicon array of chips (35 mm cameras have an image area of 24 x 36 mm) Each number in the Array represents one Picture Element (Pixel).

David E. Pitts Digital Cameras 101

David E. Pitts Digital Cameras 101 Each pixel on the silicon array has a blue, red, or green filter over it. Interpolation is used to obtain all 3 colors for each pixel. Green is used more because it is near the peak of the solar spectrum.

David E. Pitts Digital Cameras 101

David E. Pitts Digital Cameras 101 Digital Image Each pixel is saved as 3 colors (Red, Green, and Blue) The grey level range in each color pixel is usually 8 bits (256 grey levels). This gives 16 million hues of color; the range of the human eye.

David E. Pitts Digital Cameras 101 Moire Patterns can be generated when photographing patterns with low cost digital cameras.

David E. Pitts Digital Cameras 101 Advantages of digital cameras Convenience - No film needed. Your photos are free so take a lot of photos and toss the bad ones. Cost - You will save on film and developing. This will quickly pay for the cost of the camera. Film cost per photo = 20 cents Developing/printing cost per film photo = 20 cents A $200 camera is paid for after 500 photos.

David E. Pitts Digital Cameras 101 Advantages of digital cameras continued Flexibility - See your images on the LCD. Take the photo again if you want to. However, detailed quality cannot be assessed on the small LCD on the back of the camera. Color – The color gamut is greater for digital cameras than for film. This means that the colors are brighter and have a greater range.

David E. Pitts Digital Cameras 101 CIE Chromaticity Diagram showing the Gamut of a CRT

David E. Pitts Digital Cameras 101 Disadvantages of digital cameras Quality - The best digital cameras match the resolution of film, but are expensive. (≥ $2,000) Shutter lag - Most inexpensive digital cameras take a few seconds to store each image. This makes them unsuitable for action photography (children). Back lighting is a serious problem– You must be careful to not compose a photo with a bright window next to the subject since the subject will be underexposed Don’t use digital zoom

David E. Pitts Digital Cameras 101

David E. Pitts Digital Cameras 101 Resolution - Generally, you'll pay more for higher resolution cameras. Capacity The size of the memory chip you purchased determines the number of photos you can store. 1 gigabyte chip will hold about 800 photos at 3.2 megapixel (Cost ≈ $25.00). Keep a couple of chips handy. Optics. Most consumer cameras (≥ $200) have zoom lenses that range from wide-angle to short telephoto. More expensive cameras have better optics. Most digital cameras come with a built-in automatic flash. Use jpg (jpeg) compression format unless you are a professional photographer.

David E. Pitts Digital Cameras 101 Film Cameras 35 mm film image is equal to megabytes Image on the film is 24 x 36 mm Film is sensitive from 0.3 to 0.9 µm Digital Cameras are sensitive into near infrared 1.1 µm. However, these wavelengths are only used on special scientific cameras.

David E. Pitts Digital Cameras 101 Professional Digital Cameras Most digital cameras have CCD sensors that are smaller than 35 mm slides (24 x 36 mm). This necessitates a conversion factor when calculating the f stop for a particular lens setting. Large raw files can result from the professional digital cameras which match 35 mm film resolution. Professional digital cameras often have 12 bit resolution for each color. Can shoot photos quickly like expensive film cameras.

David E. Pitts Digital Cameras 101 DIGITAL CAMERAS Foveon Inc. has created a new CMOS CCD which has 3 detectors for each pixel on a single chip. Current single chip cameras require adjacent detectors for each color, thereby requiring interpolation. Camera using the X3 chip is available now, 10 megapixels Sigma SD10, $1,350.00,

David E. Pitts Digital Cameras 101 Print capability versus camera resolution 3.2 megapixels produces quality 4 x 6 inch prints 8 megapixels produces quality 30 x 40 inch prints

David E. Pitts Digital Cameras 101 Archiving your digital photos Prints Walmart, Sams Club, etc PictBridge capability allows direct connection to a printer without a computer

David E. Pitts Digital Cameras 101 Archiving your digital photos continued CD’s and DVD’s Optical Media Dye layer in plastic substrate (lifetime 2 to 5 years) CD SINGLE SIDED 700 megabytes DVD (Digital Video Disc) Single layer 4.7 Gigabytes, dual layer 9 Gigabytes

David E. Pitts Digital Cameras 101 Archiving your digital photos Film is the best media for preserving data more than 5 years. First permanent photographic images 1834 Henry Fox Talbot 1837: Louis Daguerre Photos which have been kept in a cool, dry, dark environment have survived from the time of the United States Civil War. Video tape only last 2 to 5 years. Sharing photos -