Re: [ATM] Star test with laser light sources

["Bob May" <bobmay@nethere.com>]

A laser tends to be a bad idea due to issues with the syncronous nature of
that light source.  A LED is not bad for a source.
The thing to remember here is that lasers tend to have the speckeling
problem when viewing the beam and that makes for a lot of problems when
looking at laser light.  Fortunately, the interfrometers use the nature of
laser light quite nicely and the speckles don't appear in that application.
The "clever" nature of lasers also makes a lot of people think that they are
desirable for most light generator applications - they do have plenty of
output in a simple low heat generating sourec.  Unfortunately, the lasers
also have a bit of a problem with other things.
I'll note that the ball should be a polished ball so that a "cluster' of
stars don't appear from the rough shape of the ball itself.  The whole
intention is to produce a spot of light which has essentially a 0 diameter
or at least less than what would generate an Airy Disc diameter spot on the
image plane of the telescope.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


_______________________________________________
ATM mailing list http://www.atmlist.net/