Glossary
Active D-Lighting A camera setting that preserves highlight and shadow details in a high-contrast scene with a wide dynamic range.
AE See Autoexposure (AE).
AF-assist illuminator An LED light that is emitted in low-light or low-contrast situations. The AF-assist illuminator provides enough light for the camera’s autofocus to work in low light.
ambient light Lighting that naturally exists in a scene.
angle of view The area of a scene that a lens can capture. The area is determined by the focal length of the lens. Lenses with a shorter focal length have a wider angle of view than lenses with a longer focal length.
aperture The opening of a lens, which is similar to the iris of the eye. The designation for each step in the aperture is called an f-stop. The smaller the f-stop (or f-number), the larger the opening of the aperture; higher f-numbers designate smaller apertures, letting in less light. The f-number is the ratio of the focal length to the aperture diameter.
Aperture-priority auto An exposure mode in which you choose the aperture and the camera automatically adjusts the shutter speed according to the camera’s metered readings. Aperture-priority auto is often used to control depth of field. See also Autoexposure (AE), Programmed auto, and Shutter-priority auto.
aspect ratio The ratio of the long edge of an image to the short edge as printed, displayed on a monitor, or captured by a digital camera. The native ratio for the D5200 is 3:2 for still images and 16:9 for video.
Autoexposure (AE) A camera mode that selects the aperture and/or shutter speed according to the camera’s built-in light meter. See also Aperture-priority auto, Programmed auto, and Shutter-priority auto.
Autoexposure/Autofocus (AE/AF) Lock A camera control that lets you lock the current metered exposure and/or autofocus setting prior to taking a photo. This allows you to meter an off-center subject and then recompose the shot while retaining the proper exposure for the subject. The function of this button can be altered in the Setup menu under the Buttons heading.
Autofocus (AF) A camera mode that determines the proper focus of the subject automatically.
backlighting A lighting effect produced when the main light source is located behind the subject. Backlighting can be used to create a silhouette effect or to illuminate translucent objects. See also frontlighting and sidelighting.
barrel distortion A lens aberration in which the lines at the horizontal and vertical edges of the image are bowed outward. This distortion is usually found in shorter focal-length (wide-angle) lenses.
bokeh The out-of-focus areas of an image. It is derived from the Japanese word boke, which is loosely translated as fuzziness.
bounce flash A technique in which the flash head is pointed upward or toward a wall so that the light bounces off another surface before reaching the subject. Bounce flash softens the light reaching the subject, and often eliminates shadows and provides smoother light for portraits.
bracketing A photographic technique in which you vary the exposure over two or more frames. This ensures proper exposure in difficult lighting situations in which your camera’s meter can be fooled.
broad lighting A lighting technique in which the main light illuminates the side of the subject facing the camera lens.
camera shake Camera movement (usually at slower shutter speeds) that produces a blurred image.
center-weighted metering A light-measuring algorithm that emphasizes the area in the middle of the frame when calculating the correct exposure for an image.
chromatic aberration A flaw in the design of a lens in which the lens doesn’t focus all of the wavelengths of light on the same plane. This is typified by color fringing at the edges of high-contrast areas of the image.
colored gel filter A translucent material that is placed over a flash head or light to change the color of the light emitted from the flash. Gels are often used to match the flash output with the ambient light. They are also used to change the color of the background when shooting a portrait or still life, by placing the gel over the flash head and then firing the flash at the background.
compression A technique that reduces the size of a file by digital encoding, which uses fewer bits of information to represent the original subject. Some compression types, such as JPEG, actually discard some image information, while others, such as lossless compressed RAW (NEF) files, preserve all the details in the original.
Continuous Servo autofocus (AF-C) A camera setting that allows the camera to focus continuously on a moving subject.
contrast The range between the lightest and darkest tones in an image. In a high-contrast image, the tones extend through the entire range between white and black. In a low-contrast image, the tones are compressed into a smaller range.
curvilinear A term used to describe a lens that does not adjust for the curvature of the lens elements, resulting in an image that appears curved, especially at the edges. Fisheye lenses are curvilinear. See also rectilinear.
dedicated flash An electronic flash unit — such as the Nikon SB-910, SB-900, SB-800, SB-700, SB-600, or SB-400 — designed to work with the autoexposure features of a specific camera.
depth of field (DOF) The portion of a scene from foreground to background that appears sharp in the image.
diffuse lighting A soft, low-contrast lighting.
Digital single-lens reflex camera (dSLR) A digital camera design in which the light from a scene enters through the lens and is reflected by a mirror into the viewfinder. This enables the photographer to see the scene exactly as it is coming through the lens. When the shutter release button is pressed, the mirror flips up and out of the way, and flips back down when the exposure is completed.
D-Lighting A camera function that can correct the underexposure that often happens to images that are backlit or in deep shadow. D-Lighting (not to be confused with Active D-Lighting) works by adjusting the levels of the image after the image has been captured.
DX The Nikon designation for digital single-lens reflex cameras (dSLRs) that use an APS-C–sized (23.6mm × 15.8mm) sensor.
dynamic range The range of brightness or luminosity in any given scene from shadow areas to highlights. Dynamic range can be wide with lots of contrast or narrow with almost no contrast.
equivalent exposure An exposure with different settings that yield the same results. For example, an exposure of ISO 400 at f/4.0 for 1/125 second is an equivalent exposure to ISO 200 at f/5.6 for 1/30 second.
equivalent focal length A DX-format digital camera’s focal length, which is translated into the corresponding values for 35mm film or the FX format.
exposure The amount of light allowed to reach a camera’s sensor, which is determined by the ISO setting, the light admitted by the aperture of the lens, and the length of time determined by the shutter speed.
exposure compensation A technique for adjusting the exposure indicated by a photographic exposure meter, in consideration of factors that may cause the indicated exposure to result in a less-than-optimal image.
exposure mode Camera settings that control how the exposure settings are determined. See also Aperture-priority auto, Programmed auto, and Shutter-priority auto.
fill flash A lighting technique in which a flash provides enough light to illuminate the subject in order to brighten the shadows. Using a flash for outdoor portraits often brightens the subject in conditions in which the camera meters light from a broader scene.
fill lighting The lighting used to illuminate shadows. Reflectors, additional incandescent lighting, or an electronic flash can be used to brighten shadows. One common outdoor technique is to use the camera’s flash as a fill.
flash An external light source that produces an almost instant flash of light to illuminate a scene. Also known as electronic flash.
Flash compensation A feature that adjusts the flash output. If images are too dark (underexposed), you can use Flash compensation to increase the flash output. If images are too bright (overexposed), you can use it to reduce the flash output. This is also sometimes referred to as Flash Exposure Compensation (FEC).
flash modes Modes that enable you to control the output of the flash by using different parameters. Some of these modes include Red-Eye Reduction and Slow Sync.
flash output level The output level of the flash as determined by one of the flash modes used.
focal plane The point at which the lens focuses the image. In a dSLR, the focal plane is where the sensor lies.
frames per second (fps) A term that describes how many images are being recorded per second.
Front-curtain sync A camera setting that causes the flash to fire at the beginning of the period when the shutter is completely open in the instant that the first curtain of the focal plane shutter finishes its movement across the film or sensor plane. This is the default setting. See also Rear-curtain sync.
frontlighting The illumination coming from the direction of the camera. See also backlighting and sidelighting.
f-stop See aperture.
FX The Nikon designation for digital single-lens reflex cameras (dSLRs) that use a 35mm-sized (36mm × 24mm) sensor.
High Dynamic Range (HDR) Imaging that allows you to portray a photograph with more tonal range than is possible to capture in a single image, by combining images with two or more exposures. HDR is also a feature on the D5200 that automatically combines two exposures and blends them together.
histogram A graphic representation of the range of tones in an image.
hot shoe The slot located on the top of the camera where the flash connects. The hot shoe is considered hot because it has electronic contacts that allow communication between the flash and the camera.
ISO sensitivity A setting that indicates the light sensitivity of a camera’s sensor. In digital cameras, a lower ISO setting provides better-quality images with less image noise; however, a lower ISO setting also requires more exposure time. ISO stands for International Organization for Standardization.
JPEG (Joint Photographic Experts Group) An image format that compresses the image data from the camera to achieve a smaller file size. The compression algorithm discards some of the detail when saving the image. The degree of compression can be adjusted, allowing a selectable trade-off between storage size and image quality. JPEG is the most common image format used by digital cameras and other photographic image-capture devices.
kelvin (K) A unit of measurement of color temperature based on a theoretical black body that glows a specific color when heated to a certain temperature. Direct sunlight is approximately 5500K.
lag time The length of time between the pressing of the shutter-release button and when the shutter releases. The lag time on the D5200 is so short that it is almost imperceptible. Compact digital cameras are notorious for having long lag times, which can cause you to miss important shots.
leading line An element in a composition that leads a viewer’s eye toward the subject.
lens flare An effect caused by stray light reflecting off the many glass elements of a lens. Lens shades typically prevent lens flare, but sometimes you can choose to use it creatively by purposely introducing flare into your image.
macro lens A lens with the capability to focus at a very close range, enabling extreme close-up photographs. Nikon calls its macro lenses micro lenses.
Manual exposure An exposure mode in which the aperture and shutter speed are controlled by the photographer, not the camera.
Matrix metering A Nikon-exclusive meter that reads the brightness and contrast throughout the entire frame and matches those readings against a database of images (over 30,000 in most Nikon cameras) to determine the best metering pattern to be used to calculate the exposure value.
metering A technique for measuring the amount of light in the scene by using a light meter.
Nikon Electronic File (NEF) The name of the Nikon RAW file format. See also RAW.
noise The appearance of pixels with randomly distributed color values in a digital image. Noise in digital photographs tends to be more pronounced in shadow areas with low-light conditions and long exposures, particularly when you set your camera to a higher ISO setting.
Noise Reduction (NR) A technology used to decrease the amount of random information in a digital image, often caused by long exposures and/or high ISO settings.
pincushion distortion A lens aberration in which the lines at the horizontal and vertical edges of the image are bowed inward. It is usually found in longer focal-length (telephoto) lenses.
Programmed auto (P) A camera setting in which the shutter speed and aperture are set automatically. See also Aperture-priority auto, Autoexposure (AE), and Shutter-priority auto.
RAW An image file format that contains the unprocessed camera data as it was captured. Using this format allows you to change image parameters, such as white balance, saturation, and sharpening. Although you can process RAW files in-camera, the preferred method requires special software, such as Adobe Camera Raw (available in Photoshop), Adobe Lightroom, or Nikon Capture NX2 or View NX 2. See also Nikon Electronic File (NEF).
Rear-curtain sync A setting that causes the flash to fire at the end of the exposure an instant before the second, or rear, curtain of the focal plane shutter begins to move. With slow shutter speeds, this feature can create a blur effect from the ambient light, showing as patterns that follow a moving subject, with the subject shown sharply frozen by the flash at the end of the blur trail. This setting is often used in conjunction with longer shutter speeds. See also Front-curtain sync.
rectilinear A term used to describe a design feature that corrects (or rectifies) for the field curvature found in wide-angle lenses. Most wide-angle lenses are rectilinear, whereas a fisheye lens is not and retains the field curvature. See also curvilinear.
red-eye An effect from flash photography that appears to make a person’s eyes glow red or an animal’s eyes glow yellow or green. This effect is caused by light bouncing off the retina. It is most noticeable in dimly lit situations (when the irises are wide open), as well as when the electronic flash is close to the lens and, therefore, prone to reflect the light directly back.
Red-Eye Reduction mode A flash mode used to prevent the subject’s eyes from appearing red. Multiple flashes are fired just before the shutter opens, causing the subject’s irises to contract, therefore reflecting less light from the retina to the camera.
selective focus A camera setting that uses shallow depth of field to isolate the subject and make it more prominent by blurring out the rest of the image.
self-timer A mechanism that delays the opening of the shutter for several seconds after the shutter-release button has been pressed.
short lighting A lighting technique in which the main light illuminates the side of the subject facing away from the camera and lens.
shutter A mechanism that allows light to pass to the sensor for a specified amount of time.
Shutter-priority auto A camera mode in which you set the desired shutter speed and the camera automatically sets the aperture for you. It is best used when shooting action shots to freeze the subject’s motion by using fast shutter speeds. See also Aperture-priority auto, Autoexposure (AE), and Programmed auto.
shutter speed The length of time the shutter is open to allow light to fall onto the imaging sensor. The shutter speed is measured in seconds or, more commonly, fractions of a second.
sidelighting Lighting that comes directly from the left or right of the subject. See also backlighting and frontlighting.
Single Servo autofocus (AF-S) A setting that locks the focus on the subject when the shutter-release button is half-pressed. This allows you to focus on the subject and then recompose the image without losing focus.
Slow Sync mode A flash mode that allows the camera’s shutter to stay open for a longer time to record ambient light. The background receives more exposure, which gives the image a more natural appearance.
Speedlight A term for Nikon accessory flashes.
spherical aberration A problem with lens design that causes the light coming through the lens not to converge at a single point, resulting in soft or unfocused images. Most lenses on the market today include an aspherical lens element that corrects this problem.
spot meter A metering system in which the exposure is based on a small area of the image. On the D5200, the spot is linked to the autofocus point.
Through-the-Lens (TTL) A metering system in which the light is measured directly through the lens.
vanishing point The point at which parallel lines converge and seem to disappear.
Vibration Reduction (VR) A function in which the lens elements are shifted by a mechanism in the lens to reduce the effects of camera shake. Note that VR is a Nikon proprietary term, and third-party lenses have other designations that mean the same thing, such as Optical Stabilization (OS; Sigma) and Vibration Compensation (VC; Tamron).
white balance A setting used to compensate for the differences in color temperature from different light sources. For example, a typical tungsten light bulb is very yellow-orange, so the camera adds blue to the image to ensure that the light looks like standard white light.
