Deciphering a Data Sheet
When you shop for a dSLR, you’ll find a bewildering array of options. Salespeople will hand you data sheets that describe in sometimes painful detail what the camera can do. In this section, I explain the major areas to look for when you go shopping for that first dSLR. By the way, this book’s Glossary is another source of information for unfamiliar terms.
Recording Medium
The recording medium is the type of memory card used by the camera, such as CF (Compact Flash) memory cards. The most common card is Type I (3.3mm thick), whereas some, such as the MicroDrive, are Type II (5mm thick). Devices equipped with Type II slots can also accept Type I cards, but not vice-versa. Other common types of memory cards used in dSLRs are SD (Secure Digital) and xD Picture Cards .
Aspect Ratio
The 3:2 aspect (width to height) ratio is the most common for digital photographs and is the same ratio that a traditional 35mm film camera uses. Other available ratios you’ll find are 4:3 and 16:9.
Color Filter System
Most dSLR image sensors use an RGB filter to record a single color on each photosensor to produce an accurate image. The exception is the Foveon X3 sensor which uses a color-separation beam-splitter prism assembly and utilizes all the light and records all colors at all locations on the sensor. This technology is currently featured in the Sigma line of dSLR cameras.
Recording and Image Format
A dSLR should take and store photos in both JPEG and raw formats. This means that images are written to the memory card in a way that can be understood by image-editing programs. Although JPEG is a widely accepted format in virtually every software application, raw files are proprietary to each individual manufacturer and require their software, or a licensed third-party application, to convert to an editable file.
File Size
Most cameras support saving JPEG files in various sizes up to a limit, normally given as maximum file size. This is the recommended manner for capture to ensure the best quality enlargements. Shooting smaller files is quicker, allows more images to be stored on a card, and is ideal for Web use.
Image-process
Some cameras enable you to create preset custom settings that can be quickly recalled for shooting specific situations, eliminating the need to select each individual setting from the menus every time you want to use them.
Interface
The interface is how the camera is connected to your computer. You’ll find either USB 2.0 or FireWire (IEEE 1394) as options. Be sure your computer has a FireWire port if you choose a camera with a FireWire interface.
White Balance
With most dSLRs, the white balance, measured in degrees Kelvin, can be set for the appropriate light source. Presets for daylight, shade, cloudy, tungsten, fluorescent, and flash are common options. All digital cameras also provide an Auto preset where the camera can more accurately determine the proper white balance based on the current light source. Finally, most cameras also let you create a custom setting for a mixed light source or specific lighting situation, such as in a studio.
