From: "Vero and Lisa Joseph" 
To: "Bill Kocken" , 
Reply-To: "Vero and Lisa Joseph" 



Bill

> Very interesting idea, using a35mm camera.  Does this result in a straight
> through image, like looking throught the viewfinder of a camera or
> binocular?

The use of the mirror alone in an L shape to bend the image 90 deg will
result in a back to front image (as well as an upsidedown image due to the
use of two biconvex lenses). I have tried to also use the pentaprism (with
no magnification) but there was too much light loss - this may well be
different once the image is magnified) - this may keep the image right way
around depending on how you configure it.

>
> I've also been intrigued by the idea of using a camera lens as a helical
> focuser.  What size lens do you use and how do you hollow it out?  For
> example, after you take the glass out( somehow),  does a 50mm f 1.8 lens
> have a big enough opening to hold a 1.25inch eyepiece?

Yes, I used a similar lens. Removing the lens elements is not too hard -
you need to unscrew the lens retaining rings and remove each. Depending on
the lens, you may also have to disassemble the helical focus to gain access
to some of the nuts. I needed to place a tube lined with felt (I used a
lobotomised capacitor) inside the now hollow focuser. The inside diameter
of the (felt lined) capacitor tube provided a snug fit for the 1 1/4 inch
eyepieces. This allowed the ep to slide in and out to compensate for the
limited travel (13mm) of the focuser itself. Another Aussie ATM (Dave
Gault) has used a zoom lens that overcomes the travel issue. The mount on
the camera that accepts the lens can be removed and mounted on your focuser
board Allowing the focuser to be removed easily.


>
> Summer is slowly coming to Minnesota.  Of course with the coming of summer
> we get mosquitos.

Sure fire cure for mozzies is drought (which we are still gripped in). Not
a bite all summer

>
> Thanks for any ideas,
> Bill Kocken

Always a pleasure to share my limited knowledge

Regards
Vero Joseph

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