• Corpus ID: 36017160

Characterising Fulldome Planetarium Projection Systems: The Limitations Imposed by Physics, and Suggestions on How to Mitigate

@inproceedings{Rner2016CharacterisingFP,
  title={Characterising Fulldome Planetarium Projection Systems: The Limitations Imposed by Physics, and Suggestions on How to Mitigate},
  author={Max R. R{\"o}{\ss}ner and Lars Lindberg Christensen and C. Ganter},
  year={2016}
}

• M. Rößner, L. Christensen, C. Ganter
• Published 2016
• Physics

Fulldome planetarium projection systems present a unique technical challenge. This includes the way light propagates in the largest optical element of a planetarium: The dome itself. In an ideal world, one would aim for a projection system with high luminance and high contrast. However, effects such as cross-reflection occur in reality, compromising the projection quality. In previously published studies, the interaction of dome reflectivity, projector parameters, projection luminance and contrast and other factors has been presented from a physical and mathematical point of view. This mathematical treatment is complemented here by actual luminance and contrast measurements in domes. The mathematical model is validated and mitigation strategies for the associated technical challenges are suggested. 1 Immersive Digital Planetarium Projection Displays Planetariums are visited by about 100 million visitors every year [1]. Despite this, very little research has been published in the field of planetarium projection systems. There are two major ways to realise projection in a planetarium: Traditionally, an optomechanical star projector in the centre of the dome projects astronomical objects as seen from the surface of the Earth. These projectors are highly optimised for this task but increasingly often are either complemented or replaced by a digital projection system that is less specialised and can be used for all kinds of content: The dome surface, typically made of coated aluminium panels, is covered by digital projection fields, seamlessly blended to create one single immersive screen. Such fulldome systems come in a variety of flavours, for example optimised for high brightness, high contrast, high resolution, low black levels or low cost of ownership. Two core properties of a projection are its brightness and its contrast. However, combining the best of these worlds in one system is difficult to impossible for fundamental physical reasons. Consequently, when designing a new planetarium, one has to make up one’s mind on what type of content the system shall be optimised for. An understanding of the physical fundamentals of dome projection can help come up with the appropriate design decisions.