glossary of terms
4K ultraHD – The next video standard beyond 1080p HD video, with a resolution of 3840 × 2160, which is twice the resolution of 1080p, and is a 16:9 aspect ratio.
Additive Mixing – The practice of overlapping different colors of light to achieve a new color. The most common example is to overlap red, blue, and green light, which additively mixes to white.
Amber Drift – The tendency of incandescent theatre lamps to become warmer as they fade down on a dimmer. This is in direct correlation with the Kelvin color temperature scale found in Figure 8.2. Many designers use this to their advantage when creating cues, but it can also result in major changes in the color temperature of people and things on stage as cues change. LED and arc sources are not subjected to this phenomenon, as LEDs dim in a different way, and arc sources do not dim, but have their intensity reduced or cut by a mechanical shutter.
Aperture – The variable-size opening in a camera lens that controls the amount of light that passes through the lens.
Aperture Priority – A camera metering mode that allows you to choose the aperture, and then allows the camera to choose the appropriate shutter speed required for optimal exposure of the shot.
APS-C (Advanced Photo System Type C) – Smaller sized image sensor found in most non-professional-grade DSLR cameras.
ASA (American Standards Association) – This organization set many standards for various industries, including setting a standard for film speed, which became synonymous with its initials. Film speeds are often expressed as 100 ASA or 400 ASA. The American Standards Association later became the American National Standards Institute, or ANSI. ASA 100 is equivalent to ISO 100.
Aspect Ratio – A mathematical ratio that expresses the relationship between the length and height of an image. Common ratios are 3:2, 4:3, and 16:9. A square would have an aspect ratio of 1:1.
Available-Light Photography – The practice of taking photographs, often in the theatre, at night, or in other darker situations, where you rely solely on the available light. No supplemental fill light, bounce light, or flashes are used.
Blocking – This refers to the carefully planned movements of the actors around the stage by the production’s director.
Bokeh – Refers to the quality (or lack thereof) of the out-of-focus portion of an image. This quality is usually a function of the particular lens that you may be using.
Bracketing – This is the practice of taking multiple exposures of the same image with slightly different settings, allowing the photographer the chance to capture a range of exposures to choose from when picking images to use. Some modern DSLR cameras have the ability to bracket automatically, which is a huge benefit in a photo-call situation.
Candela – One of several ways to measure light intensity. www.dictionary.com/browse/candela?s=t
Capture Medium – The material responsible for capturing the light passing through the lens and shutter assemblies, and fixing that light as a permanent image. In analog cameras, this would be the film in the camera, and in modern digital cameras, this would be a CMOS sensor.
Cibachrome – This is a type of photographic paper, later known as Ilfochrome, that was used for making color prints of color positive transparencies (slides). This process, while costly, was infinitely superior in quality to the other option of having an inter-negative made from the slide, and then printing a positive color print from the inter-negative.
Color Rendering Index (CRI) – This is a measurement from 0 to 100 that indicates how well a given source renders light compared to a perfect reference source. The higher the number, the better and more accurate the colors will appear under that particular source.
Color Temperature – Measured in degrees Kelvin, this is a quantification of how warm or cold white light appears.
CMOS Sensor (Complementary Metal-Oxide-Semiconductor) – A digital computer chip designed specifically to capture visible light energy and transmit it to other computer chips that ultimately save the data as an image file.
Cropping – The practice of trimming a photo down by physically or digitally cutting off one or more sides to create a smaller version of the previous image.
Depth-of-Field – Refers to the camera’s ability to render a sharp or soft focus of objects at different distances from the lens. This function is affected by the distance of the camera to the object as well as the chosen aperture. A shallow depth-of-field means that only some of the objects are in focus at a given time.
DSLR (Digital Single-Lens Reflex) – A digital version of the standard SLR (Single-Lens Reflex) camera that replaces the film with an electronic image-capture device. The camera still allows the photographer to view the image to be captured through the actual lens, utilizing the same mirror and prism construction of a typical SLR.
Digital Zoom – Some cameras allow the image being captured to be digitally enlarged beyond what is possible with the optical zoom of the camera, although quality is often lost.
EI (Exposure Index) – Another, less common, term for film speed or ISO sensitivity.
Film Speed – In film photography, film is rated at different speeds, with faster speeds having greater light sensitivity. The concept of film speed continues to exist in digital photography, and refers to the sensitivity of the image-capturing device used to record the image.
Fixed-Focus Lens – Otherwise known as a prime lens, this is a lens with a fixed focal length, as opposed to a zoom lens that can change its focal length.
Foot-Candle – One of several ways to measure light intensity. www.dictionary.com/browse/foot-candle
Full Bleed – If a photograph is printed without a border, it is referred to this way. Essentially, the photographic image covers the print all the way to all four edges.
Full-Frame Lens – This is a lens that is designed to work with a full-frame DSLR CMOS sensor, as opposed to a cropped sensor such as the APS-C sensor.
Full Spectrum – Refers to lighting sources that emit light across the entire visible portion of the electromagnetic spectrum. This includes the sun, incandescent light bulbs, and incandescent theatre lights. The relative power of each wavelength may vary across the spectrum, which gives each source its distinct luminous quality.
Golden Ratio – Another term for the Golden Rectangle.
Golden Rectangle – A mathematical ratio of 1:1.618, which governs the proportions of many areas of art, including architecture, painting, drawing, and photography.
GIF (Graphics Interchange Format) – One of several common digital image formats.
Grain – Film and digital images that are of poor quality due to poor exposure, enlargement, or higher film speeds are often referred to as “grainy,” in reference to the lower quality of the image. Digital images might also be referred to as pixelated.
HDR (High Dynamic Range Photography) – A type of digital photography and image manipulation that involves the layering of multiple varying exposures of a single image to create more depth and dramatic contrasts in the light and shadows.
Hue – In color mixing, this refers to the actual color, regardless of value or saturation.
Inverse Square Law – Light intensity decreases over distance and is governed by the equation: ∆I = 1/∆D2, which means that the Change in Intensity = 1/Change in Distance2.
ISO (International Organization for Standardization) – This is the international version of the ASA (American Standards Association). This organization set many standards for various industries, including setting a standard for film speed, which became synonymous with its initials. Film speeds are often expressed as ISO 100 or ISO 400. ISO 100 is equivalent to ASA 100.
JPEG (Joint Photographic Experts Group) – Also written as JPG, this is the most common digital image format.
Kelvin – Temperature scale that begins at absolute zero, and is used to measure the color temperature of light.
Lumen – One of several ways to measure light intensity. www.dictionary.com/browse/lumen?s=t
Luminous Quality – Refers to the feel and appearance of the light emitted by different sources before it is altered by gels, dichroic glass filters, or other subtractive or additive color– mixing methods. This refers to the overall difference that you may perceive when viewing sunlight versus candlelight.
Lux – One of several ways to measure light intensity. www.dictionary.com/browse/lux?s=t
Megapixels – A measurement for the resolution of an image sensor in a camera, which is equivalent to 1,048,576 pixels.
Metadata – This is the data that refers to all the various camera settings associated with a digital image, and is stored as part of the image file.
Mirrorless Camera – Also known as a Mirrorless Interchangeable Lens Camera (MILC), is a new form of digital camera that eliminates the entire mirror and pentagonal prism that has defined the design of typical TTL film and DSLR cameras.
NEF (Nikon Encapsulated Format) – A brand-specific version of the RAW format for storing digital images.
Noise Reduction (NR) – A digital filter that can be applied in-camera to reduce pixilation or grain in high-ISO images.
Optical Zoom – A camera with an optical zoom has a lens with multiple adjustable glass elements that allows the user to zoom in or out, changing the effective focal length of the lens, and thus the size or magnification of the image.
Paracord – A lightweight synthetic cord originally used by the military for rigging parachutes. Similar in diameter to theatrical tie-line, available in many colors, and very strong for its size and weight.
Pixel – The smallest element of a digital image that is individually addressable in terms of hue and saturation.
Pixelated – Refers to an image that is of lower quality. Often interchangeably used with the term “grainy.”
Prime Lens – Another term for a fixed-focus lens, this is a lens that cannot zoom, and has a fixed angle of view.
Prosumer – Refers to equipment that falls between the levels of features expected by your average amateur versus those expected by professionals working on a daily basis in the industry. Prosumer equipment is usually more feature-rich, with price tags to match.
Push – A method of shooting film at a higher ASA rating, and then processing the film in a slightly different way, allowing the photographer to gain extra light sensitivity from the film.
Push Processing – The processing portion of the technique of “pushing” film.
Rangefinder Camera – A camera without TTL focusing. The user views the image through a secondary viewfinder and not the actual lens used for the shot.
RAW – This is an image format that allows for the most information about the image to be captured and stored. In addition to a much greater pixel count for the image, the format can store a great amount of the image’s metadata.
Rule of Thirds – This is a common rule that is applied to the composition of an image. Divide the image into thirds vertically and horizontally to find the intersections that create dynamic interest and focus.
Saturation – In color mixing, this refers to the amount of color present in a particular hue, as opposed to its actual hue or value. Lighter saturations are referred to as tints, and heavier saturations are referred to as shades of a particular hue.
Shutter Priority – A camera metering mode that allows you to choose the shutter speed, and then allows the camera to choose the appropriate aperture required for optimal exposure of the shot.
Shutter Release – Either the button on the camera that causes the shutter curtain to retract, exposing the film or image sensor to the light, or that otherwise causes the camera to capture the image.
Shutter Speed – Refers to the duration of time that the shutter will remain open, exposing the capture media to light.
SLR (Single-Lens Reflex) – A common type of film camera that utilizes a prism and a moveable mirror to allow the photographer to view the image to be captured through the actual lens. When the shutter release button is pressed, the mirror flips up out of the way, and the shutter curtain moves aside to allow the light from the image to pass directly through the lens to the film.
Spectral Power Distribution (SPD) – This is a graphical representation of the radiant power emitted by a specific lighting source as measured across the visible spectrum. This provides the viewer with a clear idea of the color composition of the light source by showing the relative intensities of the light at each of the different wavelengths.
Stop – A relative measurement of light that is either half as much light or twice as much light as an adjacent setting.
Subtractive Mixing – The practice of using multiple color filters in the same lighting fixture to remove certain wavelengths of light in order to mix a new color. This is often done with the secondary colors, cyan, magenta, and yellow.
TIFF (Tagged Image File Format) – One of several common digital image formats.
TTL (Through-the-Lens) – This acronym refers to the design of typical SLR and DSLR cameras, where the user is viewing the shot they will be taking through the actual camera lens, courtesy of an arrangement including a five-sided prism and a moveable mirror that lives in front of the shutter curtain.
Value – In color mixing, this refers to the lightness or darkness of a particular color, as opposed to its hue or saturation.
Vibration Reduction (VR) – A system commonly found in longer prime and zoom lenses that helps to reduce vibration in the recorded image.
Vignette – A darkening of the image found at the corners and possibly all edges of a shot. Usually caused by the incorrect lens hood, or a stack of multiple filters on the end of the lens.
White Balance – A setting in your camera that allows you to determine the proper color temperature for a photograph.