Fulldome refers to immersive dome-based video display 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.

Initial approaches to moving fulldome imagery used wide-angle lenses, both 35mm and 70 mm film, 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 blank (though, due to seating arrangements, that part of the dome was not seen by most viewers). 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.

Newer emerging technologies include flexible curved LED displays installed at the fulldome MSG Sphere with assistance from Industrial Light and Magic. They are working together with 360-degree content creators to create feature-length fulldome content utilizing 360 degree cameras including Red Digital Cinema.

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 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-projector fulldome video systems use a single (or mixed) 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. The main disadvantage of single fisheye systems is that they are limited to the resolution of one projector, and in the smallest dimension of the video image to cover a full dome. Another 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. However, this disadvantage fades as audience size increases (everyone cannot be at the center of the dome anyway).

Single-projector mirror systems, initially pioneered by Mirrordome at Swinburne University, are now offered by various manufacturers. These systems are positioned along the edge of the dome to enhance seating capacity, reduce costs, and facilitate the transition of analog planetariums to digital formats without sacrificing their star projectors. It is also possible to build such a system at relatively low cost. The main disadvantage is noticeably lower projection quality compared to purpose-built lenses, despite being able to project a higher proportion of the projector resolution.

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 and color differences between segments. Even minor performance differences between projectors can be obvious when projecting a solid color across the entire scene. Edge blended areas where projectors overlap often have some smearing, double images, and can have very obvious additive black level areas if poorly designed or configured.