Barco “I-DOME” for planetariums goes DLP™
At this year’s Middle Atlantic Planetarium Conference, Barco demonstrated its new SIM4 single chip DLP™ projectors in a typical planetarium set-up at the Einstein Planetarium (National Air and Space Museum – Washington). With it’s flexibility and high contrast, the SIM 4 demonstrated that it can be one of the possible technologies used in Barco’s “I-DOME” integrated all dome digital projection system, allowing planetariums to widen their scope and engage in exciting new applications.
For the conference, two Barco SIM4’s were placed at the perimeter of the 21m diameter darkened dome, projecting overlapping images from the zenith and a horizon channel. Showing content from Sky-Skan's “Infinity Express” planetarium show, the images displayed were approximately the same size as those from the planetarium CRT projectors. The demonstration showed that the SIM4 with its unique features is an alternative to CRT projectors in planetariums. Especially the Extended Contrast Ratio feature, that allows to reduce the black level and maintain a maximum contrast, makes it suited for highly demanding applications.
Barco’s SIM4 was specifically designed for multi-channel projection on curved and hemispherical screens, featuring perfect color matching; excellent color uniformity and color saturation; automated brightness matching; built-in geometry distortion; built-in edge-blending; and excellent contrast.
“The integrated lens shift can achieve 100% vertical optical off-axis projection,” explained Phil Laney, Barco Market Development Manager “this allows the projector to fill the screen, without loss of pixels when placed at the bottom of the screen in the perimeter of the dome. This capability allowed by the telecentric optical engine built by Barco, is but one of the unique features of the SIM4.”
The importance of integrating Barco’s FLEX4™ Non-Linear Image Mapping technology during manufacture is that projector power supply needs can be addressed. Also the gamma controls within the projector can be modulated to prevent the "beating" effect when a separate geometry correction board or box is used. To address multi-channel projection needs, each Sim4 projector is assembled as a color gamut matched projector with Dynacolor™, so that no matter when a Sim4 is purchased, identical color matching may be achieved across all projection channels.
Equally important for planetarium applications is Barco’s proprietary optical blending. Whereas electronic blending is easily controlled and produces good results with CRT projectors; electronic blending fails for very dark, near to black images from a matrix based projector like a DLP™ or LCD type projector. This is because all matrix based projectors leak a little light when in the black state. This light cannot be stopped electrically, so overlaps are twice as bright as that of a single projector. However, Barco’s proprietary optical blend results in black levels overlaps that equal that of the separate images, reaching a quality level equal to the soft edge overlap achieved through CRT projectors
Barco SIM4 single chip DLP projectors are but one of the possibilities offered within the Barco “I-DOME “ integrated all dome digital projection system. Barco’s “I-DOME” system covers the total planetarium dome. The proprietary developed projectors of the “I-DOME” are located in the perimeter of the dome. Especially impressive is the capability to project and seamlessly blend the Zenith part from a projector positioned in the perimeter of the planetarium, thus making room for extra visitor seats.
As Barco’s I-DOME system handles the complete visualization, including predistortion and blending of the images through dedicated electronics inside the Barco projectors, a correct geometry is achieved on the dome screen, without requiring additional computational power. This total planetarium visualization solution from Barco considerably widens the scope for image generation, allowing the use of high grade PC’s. And most important of all, it gives a planetarium the capability to simultaneously contribute to various exhibitions and events, since the “I-DOME” can project whatever content is provided by the computers.
About Barco
Barco, an international company headquartered in Kortrijk, Belgium, is active in three key areas of imaging technology. Barco designs and develops solutions for large screen visualization, display solutions for life-critical applications, and systems for visual inspection. Barco has a network of subsidiaries, distributors and agents in almost 100 countries. Barco is quoted on Brussels/Euronext and is a
BEL 20 and a Next 150 company.
