Projector with the greatest projection angle

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Discussion Overview

The discussion revolves around identifying the projector with the widest projection angle, exploring the limitations of current technologies, and considering alternative light sources like LEDs. It encompasses theoretical aspects of optics, practical applications in cinema, and potential advancements in projection technology.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants inquire about the projector with the widest projection angle and the limitations of current technologies.
  • One participant suggests that the limitation is primarily due to the brightness of the source, noting that as the projection field increases, the required lamp brightness approaches damage thresholds for film stock.
  • Another participant mentions that while there are fish-eye designs covering close to 180 degrees, IMAX theaters utilize multiple projectors to cover a hemisphere.
  • There is a proposal that using LED light instead of incandescent sources could potentially solve brightness issues, although this is challenged by another participant who states that LED brightness does not match that of arc sources.
  • A participant discusses the inefficiency of incandescent bulbs, suggesting that filters could be used to reduce infrared waste and improve projection efficiency.
  • There are considerations about the feasibility of larger projection surfaces using LED technology, including the idea of spreading simple white LEDs over a wide area and concentrating their light with lenses.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of LED technology compared to traditional light sources, and there is no consensus on the best approach to achieving wider projection angles or overcoming current limitations.

Contextual Notes

Limitations include the dependence on light source technology, unresolved questions about the efficiency of proposed solutions, and the practical challenges of implementing larger projection systems.

SAZAR
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A bit about optics. I was wondering what is the film (slide, or motion picture) projector with the widest projection angle. What are the current limitations?
 
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The limitation is on the source brightness; as the projection field increases, the lamp must be brighter and brighter, which approaches damage thresholds of the film stock. Possibly the newer direct projection technologies (like the TI micro-mirror based technology) can overcome this. The problem is not really the optics: there are lots of fish-eye designs that cover close to 180 degrees field of view.

There are IMAX theaters that cover a hemisphere, but those use multiple projector system, AFAIK.
 
Hmm... But, if projectors were using LED light instead of incandescent source, it could solve the problem, right?
 
LED brightness does not come anywhere near close to arc sources.
 
Quote:
"There are IMAX theaters that cover a hemisphere, but those use multiple projector system, AFAIK. "

It would be nice to have one unit which projects upwards and covers even more than half of sphere (some 15m diameter or greater)...

Incandescent light bulbs create more useless wavelengths (infrared) than visible light (somewhere they say that 90% is wasted on heat) - maybe the heat problem in projectors could be solved with filters which pass only visible light to film?

I like those micromirrors projectors... LED technology...

Maybe it's not much of a problem to make even larger surface - based on LED semi-conductors technology, but spread on a greater surface - tightly packed -- that could create strong light...

On the other hand - simple white LEDs could be spread on wide rectangular surface, and then their light could be concentrated on a film with some lenses - right? Hmm, I wonder how large surface would be needed for cinemas?
 

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