Projection - Mirror Collimation

[Guest cadum]

Hi,Searching trough the net and reading about mirror collimation I started to think that it may be a good solution. But I'm having trouble to find info to assist the construction needs, such as distances and correct positioning to make it work correctly. It is required any special rear projection screen ?The mirror may be done with aluminized lexan ... Is it ok ?Thanks,Cadu

[jmig 100]

If you do a search on this site you will find several threads on the subject of projectors. I don't know if any delt with mirrors. I recall that being on of the problems mentioned by the people who were using projection.A good cheap mirror is hard to find, if it even exsitsJohn

[tigert 0]

>If you do a search on this site you will find several threads>on the subject of projectors. I don't know if any delt with>mirrors. I recall that being on of the problems mentioned by>the people who were using projection.>>A good cheap mirror is hard to find, if it even exsits>>JohnFor collimation you need a curved mirror, those are hard to construct. I think the "Big" sims use a silver foil that is stretched smooth to a paraboloid shape with a vacuum pump.A flat mirror wont give you the collimated "depth" feeling.Tuomas

[Guest MikePowell]

Cadu,There is some information on my site that may be of interest to you. http://www.mikesflightdeck.com/mirror_coll...ed_displays.htm There is a brief explanation that probably covers material you already know. Further down the page there are a number of links to additional information.Glass Mountain Optics in particular is interesting because of their explanation of how a mirror collimated system functions http://www.glassmountain.com/collsys.htm and because they sell lower cost mirrors for "entertainment".You might also take a look at the University of Strathclyde links as they have made some very large spherical surface mirrors using aluminized Mylar.Mikewww.mikesflightdeck.com

[rickalty 0]

Interesting, Mike.I was at high school in SE England in 1974, and our school Astronomy club made a 10 foot diameter plastic mirror out of plastic sheet coated with a Navy surplus silver paint for repairing gun optics and projected the image of an eclipse onto a screen for an open night. I see that the author of that piece you reference is from Surrey - I wonder if our teacher was in contact with him through some sky and scope club back then and got the idea from him - I don't recall any discussions about how to do such a thing, the plans just sort of sprang into being fully formed.Richard

[Guest cadum]

I found the material in your site very interesting ! But now I'm having a different problem... What about the geometry of the optic devices ?Thanks,By the way .. congrats for your site Mike!!

[Guest MikePowell]

Thank you, Cadu.Other than the rough figures on the site, I don't have figures for the geometry of the optics.Mikewww.mikesflightdeck.com