Cinematography

Aperture

The opening of a diaphragm through which light passes through a lens on a camera to its objective, either a film negative or a digital sensor. Measured in F-Stop, which is the theoretical value of a len’s aperture based on its construction and T-Stop, which is the actual measured results...

Aspect ratio

The ratio between the width and the height of an image or screen. Some common film/TV production aspect ratios are 1.85(flat), 2.35/2.39(scope/anamorphic), and 16:9.

Bi-color

A luminaire with the ability to toggle between daylight and incandescent color temperatures, as opposed to a full-color luminaire which covers a much broader color spectrum.

Bit-depth

The number of binary digits used to store a value, such as a pixel’s color. Higher bit-depths offer greater accuracy. An 8-bit image can display 256 color values for red, green, and blue, equaling ~16.7 million colors. A 16-bit image raises that number to ~4.3 trillion colors. Some common bit...

Bokeh

The aesthetic quality of the blur in out of focus areas of an image. Bokeh is often used to make virtual cinematography appear more realistic. See also circle of confusion.

Circle of confusion

The measurement of where an unfocused point of light becomes a circle passing through a lens onto the film back or digital sensor of a camera. Is a characteristic of the lens’s depth of field. See also Bokeh.

Clipping

1. In image processing, the loss of detail of an image in areas whose intensity falls outside of the minimum or maximum range of the capture device. 2. In rendering, the area of a scene which falls outside of the field of view or near/far clipping plane of the virtual...

Color rendition

The ability of a light source, such as a cinema luminaire or an LED wall, to render the color spectrum accurately; units include CRI, SSI, TLCI, and TM30. Current LED volumes have a reduced color rendition when compared to daylight and to incandescent lights.

Color science

The field and techniques for measuring, processing, and displaying color accurately.

Color space

Standards for representing the range of color in an image, based on components such as color bands ( i.e., Red, Green, Blue), spectrum, hue, saturation, lightness, value, and other measurements.

Depth of field

The nearest and furthest area in focus on a camera lens. Determined by the focal length, aperture, camera-to-subject distance of the lens, camera sensor size, etc.

Dolly wall

A section of LED panels built onto a mobile platform for easy repositioning and use as a reflection source and other purposes. Also called roaming panels or roaming walls.

Edge diffraction

A light-interference phenomenon that occurs around high-contrast edges of an object, such as LED screens.

Eyeline

Where an actor looks during a scene; must match to preserve spatial continuity shot to shot. Eyelines can present a particular challenge in virtual production when characters may be filmed asynchronously or at varying scales.

F-stop

The mathematical measurement of the aperture of a lens, which determines how much light it lets in and affects exposure and depth of field. A T-stop is the actual measurement of light transmitted through the lens.

Field of view (FOV)

The portion of the world that can be seen at any given moment by a person or camera. For a camera, FOV is measured in degrees and based on the focal length of the lens and the size of the camera’s image sensor or film back.

FIZ (Focus, Iris, Zoom)

A control system which enables the remote control of focus, iris, and zoom settings on a camera lens simultaneously.

Focal length

The measure of the magnification power of a lens, typically given in millimeters; the higher the number, the greater the magnification.

Gamut

The portion of the visible spectrum that a display can accurately reproduce or a camera can accurately capture, e.g., Rec.709, DCI-P3, and Rec. 2020.

Genlock

A technique used to synchronize the signal coming out of a signal generator or similar source to other video signal sources; it ensures frames and subframes stay in sync. Also important for high frame rate systems that work in combination while doing performance capture.

High Dynamic Range (HDR)

The representation of a greater dynamic range of luminosity than is possible with standard digital imaging techniques. HDR images retain detail in a fuller range of lights and darks than standard images.

Incident lighting

Lighting on a subject which comes directly from a source; as opposed to indirect lighting, which is reflected or bounced before reaching the subject.

Indirect lighting

Lighting on a subject which is reflected or bounced before reaching the subject; as opposed to incident lighting, which comes directly from a source.

LIDAR (Light imaging, detection, and ranging)

A survey method that illuminates a target with laser and measures the reflected light via infrared sensors to derive a point cloud; useful as part of asset creation and to capture real-world locations.

Light card

A virtual light placed on the surface of the volume to assist with lighting the subject, can be any shape, hue, intensity, and opacity.

Light contamination

The presence of unintentional light effects on a given surface, such as the spill from movie lights onto an LED wall.

Look up table (LUT)

A mathematical formula or matrix that acts as a color correction, such as transforming between a RAW camera image and the desired display appearance such as an SDR or HDR monitor.

Luminaire

A discrete, integrated device designed specifically for lighting; LED panels create incident lighting but are not designed as luminaires.

Moiré

An undesirable interference pattern caused by the mismatch between the sensors on a digital camera and a complex, repetitive pattern. E.g. moiré can be caused by focusing a camera directly on an LED screen.

Nit

A measurement of the light intensity of a display screen. One nit is equal to one candela (one candlepower) per square meter.

OpenColorIO (OCIO)

A system that enables color transforms and image display to be handled in a consistent manner across multiple graphics applications.

Parallax

The perceptual difference in an object’s position when seen from different vantage points.

Photogrammetry

The automated construction of a 3D model asset triangulated from multiple 2D photographs; can also be combined with point clouds derived from LIDAR scans, aka sensor fusion. See also image based modeling.

Pre-light

The process of lighting a scene before the main production unit arrives in order to facilitate complex setups and maximize the full crew’s efficiency. Can apply to physical production or to prelighting virtual environments as they are developed.

Raster scan lines

Visible distortion which can appear as lines or wave patterns on camera such as when capturing an LED panel without proper genlock or a camera shutter out of phase with the display’s timing.

Spectral response

The portion of the color spectrum a given light source emits. LED panels, due to their use of RGB LED bulbs, have a reduced spectral response compared to full-spectrum cinema lights.

Videogrammetry

The automated construction of a 3D model triangulated from video. See also photogrammetry.

Virtual cinematography

The process of creating virtual imagery which may incorporate aspects of real-world cinematography. Virtual cinematography can be used to build complete virtual worlds from scratch and manipulate them with real-world input. The process includes all of the visualization phases of a virtual production from previs through live-action shooting and into...