Re: ATM A few questions before I screw my Dob together for the firsttime..

["Marinus A. (Rien) van der Lugt" <marinus@lugt.freeserve.co.uk>]

>> I have used a black marker to darken the edge of the diagonal
mirror, should
>>  I do the same for the primary?

Without an eyepiece, look into the focuser. Anything you can see
(except for the mirrors surfaces) should be as black as possible.
Thus the bevel should be darkened.
As for the mirror surface, our great hero "Tex" alway blackend the
extreme edge of the mirror, even when it was perfect because
it is impossible to measure the extreme edge. Depending on
how good your edge is, you may want to blacken the outer 1mm
or more.

>>  Also, should I put a mark or a sticker in
>>  the center of the primary to aid in collimation?

Only if you know what to use it for. IMHO it helps to first get a
good idea of what the collimation process is, and what the
purpose is. Once you know that, you will know whether or
not you'll want this sticker.

On the optical side, a sticker in the center of the primary
does not hurt. But don't put a marker in the center of the
secondary.


Rien,

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