• Complementary Metal-Oxide Semiconductor (CMOS): The other of the two main types of image sensors used in today's digital cameras. Although it's not as widely used as CCD sensors, it works much the same as a CCD sensor.

• Cyan, Magenta, Yellow, Black (CMYK): A process used in printing, sometimes referred to as four-color process. Model Aviation (as well as most other magazines) is printed using this technique. All digital photos must be converted to this process to print correctly.

• CompactFlash: The most common type of memory card. There are two kinds: Type I and Type II. Although they vary in thickness, both are roughly the size of a matchbook. This is by far the most popular type of storage in digital cameras. They also come in a wide variety of sizes as large as 1 gigabyte (1,000 megabytes).

• Depth of Field (DOF): The portion of the image which is in focus. The shorter the focal length, the greater the DOF. The camera's f-stop also affects the DOF. A larger opening (smaller f-stop) will give a short DOF, and a smaller opening (larger f-stop) will give a larger DOF.

• Digital Zoom: Magnification obtained by electronically enlarging the photo. Many cameras can do this, but it should be used only when no other options exist. Enlarging a photo in this manner causes extreme loss of image quality, resulting in jagged, fuzzy photos. In most cases the photo can be enlarged with much better results using computer software.

Shooting a model at eye level can show a great deal of detail and color,
but this isn't always the best way—especially with a Scale subject.

The same model photographed at ground level approximates the view you would
have of the full-scale subject. This angle maximizes the model's scale "look."

• Dots Per Inch (dpi): A measurement of a digital camera, printer, monitor, etc. used to describe its resolution. Most computer monitors are 72 dpi, and most printed photos (such as in this magazine) are 300 dpi. The higher the dpi, the greater the resolution of the device.

• F-stop: Inside the camera's lens is an aperture that works just like the iris in your eye. The size of the opening can be changed automatically or manually, depending on the camera. The amount of the opening is given a number, or f-stop.
    Lower numbers (e.g. f-2.8) will allow more light through the lens, allowing you to take the shot using a higher shutter speed. Higher numbers (e.g. f-22) will allow less light through the lens, requiring a slower shutter speed.

• FireWire (IEEE 1394): Technology for transferring files between digital devices, such as a camera and a computer, at high speed. A FireWire connection is typically faster than a USB connection. FireWire was developed by Apple Computer and is widely used in most computers. However, only higher-priced digital cameras have this capability.

• Focal Length: The amount of magnification of the lens. A zoom lens will give you an adjustable focal length (normally 28-200mm).

• Gigabyte (GB): Measurement of data storage equal to 1,000 megabytes.

• Histogram: A graphic representation of the range of tones (dark to light) captured in a photo. Some digital cameras include this feature to give a precise check on a photo's exposure.

• Image resolution: Commonly referred to as the number of pixels in a digital photo.

• ISO: This is one of the few terms that came over from traditional film photography. Film is rated to tell its sensitivity to light. The higher the ISO number, the more likely the film is to capture a fast-moving or dimly lit object. The numbers 100, 200, 400, and higher are printed on film packages.
    Digital-camera manufacturers have adopted the same rating system for describing the sensitivity of the camera's imaging sensor. Some digital cameras include a control for adjusting the ISO speed, and others adjust the ISO automatically, depending on the lighting conditions.

• JPEG: A compression method used within a file format, such as the EXIF-JPEG format common to digital cameras. This is a "lossy" format, which means that image quality is discarded to compress the image. Most cameras have several settings for JPEG compression. When selecting a low-compression (high-quality) setting, the loss of image quality is not as noticeable.