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Fulldome is used to refer to immersive dome-based video projection environments. The dome, horizontal or tilted, is filled with real-time (interactive) or pre-rendered (linear) computer animations, live capture images, or composited environments.
Although the current technology emerged in the early-to-mid 1990s, fulldome environments have evolved from numerous influences, including immersive art and storytelling, with technological roots in domed architecture, planetariums, multi-projector film environments, flight simulation, and virtual reality. See also 1990s, the band The 1990s decade refers to the years from 1990 to 1999, inclusive, sometimes informally including popular culture from the very late 1980s and from 2000 and beyond. ...
This article is about the building structural element. ...
// A planetarium is a theater built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. ...
A flight simulator is a system that tries to replicate, or simulate, the experience of flying an airplane as closely and realistically as possible. ...
Virtual reality (VR) is a technology which allows a user to interact with a computer-simulated environment, be it a real or imagined one. ...
Initial approaches to moving fulldome imagery used wide-angle filmstock, both 35 and 70 mm, but the expense and ungainly nature of the film medium prevented much progress; furthermore, film formats such as OmniMax did not cover the full two pi steradians of the dome surface, leaving a section of the dome (and the viewer’s peripheral vision) blank. Later approaches to fulldome utilized monochromatic vector graphics systems projected through a fisheye lens. Contemporary configurations employ raster video projectors, either singly or grouped together to cover the dome surface with full-color images and animations. Film stock is the term for photographic film on which films are recorded. ...
IMAX (for Image Maximum) is a film projection system which has the capacity to display images of far greater size and resolution than conventional film display systems. ...
The steradian (ste from Greek stereos, solid) is the SI derived unit of solid angle, and the 3-dimensional equivalent of the radian. ...
Peripheral vision is a part of vision that occurs outside the very center of gaze. ...
Example showing effect of vector graphics on scale: (a) original vector-based illustration; (b) illustration magnified 8x as a vector image; (c) illustration magnified 8x as a raster image. ...
The goal of fulldome video is to create an immersive experience, “exploding the frame” in the words of Ben Shedd, where the frame to which he refers relates to experiences typified by “framed” cinematic art. Film theory debates the essence of the cinema and provides conceptual frameworks for analyzing, among other things, the film image, narrative structure, the function of film artists, the relationship of film to reality, and the film spectators position in the cinematic experience. ...
Fulldome Technology
Fulldome video projection can use a variety of technologies in two typical formats: single- and multiple-projector systems. The individual projector(s) can be driven by a variety of video sources, typically feeding material rendered in either real-time or “pre-rendered” modes. The end result is a video image that covers an entire domed projection surface, yielding an immersive experience that fills a viewer’s field of view.
Single- versus Multiple-Projector Systems Single-projector fulldome video systems use a single (or muxed) video source displayed through a single fisheye lens, typically located at or near the center of a hemispherical projection surface. A single projector has the benefit of avoiding edge blends (see below) between multiple projectors. A disadvantage of central projectors is the loss of the center of the dome for optimal viewing of the reconstructed perspective view provided by true hemispheric projection, a problem shared with traditional Planetarium projectors. High quality hemispheric projection lenses are very expensive and operate at the practical limits of optical performance needed for high resolution full dome coverage.
Multiple-projector fulldome video systems rely on two or more video projectors edge-blended to create a seamless image that covers a hemispherical projection surface; splitting the entire image up into segments allows for higher-resolution imagery and projector placement that does not intrude on the viewing area underneath the dome. A disadvantage of multiple projection is the need to frequently adjust the alignment of projectors and the uneven aging of separate projectors leading to brightness differences between segments. Even minor performance differences between projectors can be obvious whan projecting a solid color across the entire scene.
Common Video Projector Technology A wide variety of video projection technologies has been employed in domes, including Cathode Ray Tube (CRT), Digital Light Processing (DLP), Liquid Crystal Display (LCD), Liquid Crystal on Silicon (LCOS), and most recently, two varieties of laser projectors (the laser video projector entry describes one version of the technology). Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT Electron guns Electron beams Focusing coils Deflection coils Anode connection Mask for separating beams for red, green, and blue part of displayed image Phosphor layer with red, green, and blue zones Close-up of the phosphor...
The DLP Logo Digital Light Processing (DLP) is a technology used in projectors and video projectors. ...
LCD redirects here. ...
Liquid crystal on silicon (LCOS or LCoS) is a micro-projection or micro-display technology typically applied in projection televisions. ...
For multi-projector systems in particular, display devices must have a low black level (i.e., project little or no light when no signal is sent to them) to allow for reasonable edge-blending between the different projector footprints. Otherwise, overlapping video images will have an additive effect, causing a complex pattern of grey to appear even when no image is being projected. This becomes particularly important for users in the planetarium field, who have a vested interest in projecting a dark night sky. The desire for projectors to “go to black” has resulted in continued use of CRT technology, even as newer and less expensive technologies have emerged. Video Black Level is the level in which there is no visible light/visual information in a video signal. ...
// A planetarium is a theater built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. ...
LCD projectors have fundamental limits on their ability to project true black as well as light, which has tended to limit their use in planetariums. LCOS and modified LCOS projectors have improved on LCD contrast ratios while also eliminating the “screen door” effect of small gaps between LCD pixels. “Dark chip” DLP projectors improve on the standard DLP design and can offer relatively inexpensive solution with bright images, but the black level requires physical baffling of the projectors. As the technology matures and reduces in price, laser projection looks promising for dome projection as it offers bright images, large dynamic range and a very wide color space. The contrast ratio is a metric of a display system, defined as the ratio of the luminosity of the brightest and the darkest color the system is capable of producing. ...
A comparison of RGB and CMYK color spaces. ...
Links to Fulldome Resources
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- Fulldome.org
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