From: "Vero and Lisa Joseph" 
To: , "bill kocken" 
Reply-To: "Vero and Lisa Joseph" 


G'Day Bill,

When I built a reflex finder, I used the mirror from an old 35mm SLR
camera. The mirror passes the image through the pentaprism for focusing and
flips out of the way when the shutter is opened. The mirror is front
surface silvered though I cannot vouch for it's flatness. Old 35mm camera's
are very cheap and easy to find - they also provide a wealth of other bits
and pieces for ATMers (a hollowed out lens makes a great focuser.

Vero Joseph
Goulburn, NSW Australia (winter is definitely in the air)


----- Original Message -----
From: "bill kocken" 
To: "atm list" 
Sent: Friday, May 23, 2003 10:34 AM Subject: ATM Making a finder scope


>
> Hi all.
> I'd like to build an 8x50 right angle correct image finder scope for use
on
> my dob.  I know I can buy one for $80 to $100 or so, but this is the ATM
> forum after all!  I think I can buy a 50mm objective with a focal length
of
> 200mm or so, or extract one from an old pair of binoculars.  I plan to use
> an old 25mm eyepiece from my first scope. Is there a good way to put
> crosshairs into the ep?  I expect I can assemble the pieces with PVC
> plumbing stuff. I have access to a nice set of rings.
> The question is, what kind of optical piece do I need to turn the optical
> train 90 degrees and present a correct image?  Does anyone know of a good
> source?  If you've got plans for one or a webpage, let me know.
>
> As long as I'm doing this, should I make something bigger, like 60mm?
>
> Thanks,
> Bill Kocken
>
>

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