Nikon manual David Busch’s Nikon D7000 Guide to Digital SLR Photography

496 David Busch’s Nikon D7000 Guide to Digital SLR Photography

JPEG A file “lossy” format (short for Joint Photographic Experts Group) that supports 24-bit color and reduces file sizes by selectively discarding image data. Digital cameras generally use JPEG compression to pack more images onto memory cards. You can select how much compression is used (and, therefore, how much information is thrown away) by selecting from among the Standard, Fine, Super Fine, or other quality settings offered by your camera. See also RAW.

Kelvin (K) A unit of measure based on the absolute temperature scale in which absolute zero is zero; it’s used to describe the color of continuous-spectrum light sources and applied when setting white balance. For example, daylight has a color temperature of about 5,500K, and a tungsten lamp has a temperature of about 3,400K.

lag time The interval between when the shutter is pressed and when the picture is actu- ally taken. During that span, the camera may be automatically focusing and calculating exposure. With digital SLRs like the Nikon D7000, lag time is generally very short; with non-dSLRs, the elapsed time easily can be one second or more under certain conditions.

latitude The degree by which exposure can be varied and still produce an acceptable photo.

lens flare A feature of conventional photography that is both a bane and a creative out- let. It is an effect produced by the reflection of light internally among elements of an optical lens. Bright light sources within or just outside the field of view cause lens flare. Flare can be reduced by the use of coatings on the lens elements or with the use of lens hoods. Photographers sometimes use the effect as a creative technique, and Photoshop includes a filter that lets you add lens flare at your whim.

lighting ratio The proportional relationship between the amount of light falling on the subject from the main light and other lights, expressed in a ratio, such as 3:1.

lossless compression An image-compression scheme, such as TIFF, that preserves all image detail. When the image is decompressed, it is identical to the original version.

lossy compression An image-compression scheme, such as JPEG, that creates smaller files by discarding image information, which can affect image quality.

macro lens A lens that provides continuous focusing from infinity to extreme close- ups, often to a reproduction ratio of 1:2 (half life-size) or 1:1 (life-size).

Matrix metering A system of exposure calculation that looks at many different seg- ments of an image to determine the brightest and darkest portions, and base f/stop and shutter speed on settings derived from a database of images. See also Center-weighted meter and Spot meter.

maximum burst The number of frames that can be exposed at the current settings until the buffer fills.