ATM Solar Filter

[Adrián Toledano <atoledan@prodigy.net.mx>]

I was thinking on building a solar filter, but I will like to know your
opinions on the ideas I have.

Take note that I live in a caribean island and do not have easy access to
mylar or comercial solar filters.


1. Cut two disk of appropiate diameter on 1/8" plate glass

2.- Make them reasonable flat on all the faces and polish them

3.- Silver one face of one of the disks

4. Protect the silvered surface sticking the second plate glass disk to the
first using canada balsam so that the silvered surface be on the middle of
the two glass disks.This is mainly because I think that a scratch on the
silver will be terribly dangerous!

5.- Place the disk in front of your telescope and enjoy it!

I know, that this kind of "lens" will place some abberrations in the optical
sistem because the surfaces will neither be perfectly flat nor perfectly
paralell, but i think that the aberrations will not be of importance.

As far as I know if enought silver is deposited on the glass the filter will
be safe for visual use, but I´m not sure. Have somebody tried this before?

All opinions are wellcome.

Thanks you

Adrian