Re: [APML] 5.5" Schmidt Woes

[Aplanatic@aol.com]

Hi John, Robert:

I've had the distinct pleasure of aligning and focusing a set a Schmidt 
camera optics/mechanics of my own making.  It takes a lot of time and 
patience the way I did it, but it does work in the end.  If you can't find 
someone to do it for you, I can share with you the steps that I took.  Just 
send me a note.  I don't know how much help I will be for a commercial 
Schmidt as I've never actually seen one.  I've been told that the alignment 
mechanics are a bit difficult to work with.  On the other hand, I know the 
folks at Celestron very well.  If it's a Celestron Schmidt maybe we can get 
the old pros there to take a look or at least give some advice.

Robert: I know Peter fairly well.  I doubt that Peter would be interested, 
but I can send him a line if you like.  I believe that a Schmidt camera owner 
should know how to align a Schmidt, but having been through it I understand 
the desire to have it done by someone else.  <g>  

In addition, most commercial Schmidt cameras can't be focused except by 
machining or shimming the film holder.  I think this is a bad design, but it 
does save the manufacturer some money and simplifies the mechanics and 
thermal matching.  It must be a heroic effort to take a half a thousandth at 
a time off of the film holder and then retest.  Yuck.

Dave Rowe

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