phoenix wrote:
Theoretically. Is it possible to construct a telescope using
holographic lens such that you flick a switch and the lens
just formed at the front. I like the idea of a very lightweight
0 wave error 6" refractor that I can carry at my back when
hiking and just putting it on the equally lightweight image
stabilizer mount when the sky has a great view.

In 4000 A.D. Can the above occur.. theoretically??

Theoretically anything that is not prevented by the laws of physics is
possible. However, many practical limitations do get in the way. Most
notably that a hologram uses diffraction and so will suffer from
horrific chromatic abberations unless it is used for monochromatic
light. Fresnel zone plates can already be used to form crude images by
diffraction. If you can live with the image quality. e.g



They have their own following in the pinhole camera community.

You could argue with some justification that modern aperture synthesis
radio telescopes are in effect holographic instruments since they
combine the phase compensated coherent signals sampled at various
locations (and times) to compute what would have been seen by a real
filled aperture.

The phase compensation issues are so difficult that I doubt if anyone
will ever make a portable optical aperture synthesis scope...

Regards,
Martin Brown