A Glossary of Terms Cinematographers Must Know

Cinematography Glossary 

A

• Aperture: The adjustable opening in a lens that controls the amount of light passing through to the camera's sensor. It is measured in f-stops. A wider aperture (smaller f-number) lets in more light and creates a shallower depth of field.
• Aspect Ratio: The ratio of the width to the height of an image or screen. Common aspect ratios include 16:9 (standard for HDTV) and 2.39:1 (anamorphic widescreen).
• Anamorphic Lens: A lens that horizontally compresses the image when shooting, which is then "unsqueezed" in post-production to create a widescreen aspect ratio. Known for its characteristic oval bokeh and horizontal lens flares.

B

• Backlight: A light source placed behind the subject, which helps to separate them from the background and create a rim of light around their edges.
• Bokeh: The aesthetic quality of the blur produced in the out-of-focus parts of an image produced by a lens. It is often seen as soft, pleasing circular highlights.
• Boom Operator: The member of the sound crew responsible for holding and positioning the microphone on a boom pole to capture the best quality audio during a shot.

C

• C-Stand (Century Stand): A versatile and heavy-duty stand used on film sets to hold lighting modifiers like flags, silks, and nets, as well as lights and other equipment.
• Color Temperature: A characteristic of visible light that measures its color on a scale from warm (yellow/orange) to cool (blue). It is measured in Kelvin (K). Tungsten lights are typically 3200K, and daylight is around 5600K.
• Composition: The arrangement of visual elements within the frame, including subjects, objects, and background. Principles include the rule of thirds, leading lines, and symmetry.

D

• Depth of Field (DoF): The range of distance in front of and behind the main subject that appears acceptably sharp. A shallow DoF keeps only the subject in focus, while a deep DoF keeps most of the scene in focus. It is controlled by aperture, focal length, and camera-to-subject distance.
• Diffusion: Any material placed in front of a light source to soften its quality, reducing harsh shadows and creating a more flattering look. Examples include silks, frost gels, and softboxes.
• Dolly: A wheeled cart or platform that the camera is mounted on. It allows for smooth, fluid camera movements towards, away from, or alongside a subject (a "dolly shot").

E

• Exposure: The total amount of light allowed to reach the camera sensor, which determines the image's brightness. It is determined by the combination of aperture, shutter speed, and ISO.
• Exposure Triangle: The relationship between the three primary elements of exposure: aperture, shutter speed, and ISO. Changing one element requires adjusting one or both of the others to maintain the same level of exposure.

F

• F-Stop (F-Number): The measurement of the aperture's opening. A lower f-number (e.g., f/1.8) indicates a wide aperture, while a higher f-number (e.g., f/16) indicates a narrow aperture. Each full stop doubles or halves the amount of light.
• Fill Light: A light source used to fill in (soften) the shadows created by the key light. It is typically less intense than the key light.
• Focal Length: The distance (in millimeters) from the optical center of a lens to the camera's sensor when the subject is in focus. It determines the lens's angle of view and magnification. Wide-angle lenses have short focal lengths, while telephoto lenses have long focal lengths.
• Follow Focus: A mechanism used by the 1st Assistant Camera (1st AC) to precisely control the focus of a lens, allowing for smooth focus pulls as a subject moves.
• Frame Rate (fps): The number of individual frames (images) captured or displayed per second. Standard cinematic frame rate is 24fps. Higher frame rates (e.g., 60fps, 120fps) are used for slow-motion playback.

G

• Gaffer: The head of the electrical department, responsible for designing and executing the lighting plan for a production. The gaffer works closely with the Director of Photography.
• Grip: A crew member responsible for rigging and setting up non-electrical equipment on set, such as camera support, dollies, cranes, and lighting modifiers. The head of the department is the Key Grip.

I

• ISO (International Organization for Standardization): The measurement of a camera sensor's sensitivity to light. A lower ISO (e.g., 100) is less sensitive and produces less noise, while a higher ISO (e.g., 3200) is more sensitive for low-light situations but can introduce digital noise or grain.

K

• Key Light: The primary and brightest light source in a scene, used to illuminate the subject and establish the overall mood and time of day.

L

• Latitude: The range of brightness values a camera sensor can capture, from the darkest shadows to the brightest highlights, without losing detail. Also known as dynamic range.
• Lens Flare: An effect that occurs when a bright, non-image-forming light source hits the lens directly, causing internal reflections and artifacts like streaks or polygonal shapes to appear in the image.

P

• Prime Lens: A lens with a fixed focal length (e.g., 50mm). Prime lenses cannot zoom but typically offer sharper images and wider maximum apertures than zoom lenses.

S

• Shutter Speed: The length of time each individual frame is exposed to light. In film, it is often expressed as a shutter angle (e.g., 180°). A standard 180° shutter at 24fps is equivalent to a shutter speed of 1/48th of a second, which produces natural-looking motion blur.
• Slate (Clapperboard): A board used at the beginning of each take to sync sound and picture. It displays key information about the scene, and the "clapping" sound provides a clear audio-visual reference point for editing.

T

• Three-Point Lighting: A classic lighting technique that uses three primary light sources: a Key Light, a Fill Light, and a Backlight. This setup effectively illuminates a subject while creating dimension and separating it from the background.

W

• White Balance: The process of setting the camera to recognize the true color white under a specific light source, ensuring that all other colors in the scene are rendered accurately. It corrects for the color temperature of the ambient light.

Z

• Zoom Lens: A lens with a variable focal length, allowing the operator to change the angle of view and magnification without physically moving the camera or changing the lens.