[ATM] Quirky idea

[vladimir.galogaza at zg.tel.hr (Vladimir Galogaza)]

Rob,

>I may actually be using the wrong terminology here.
Wrong terminology indeed.

Even this seems to be wrong:

>What I am using for magnification is focal length of
>the telescope, in my case 750mm divided by the
>aperture of the eyepiece, say 12 mm

because convention is that the magnification is
dimensionless number obtained by dividing two focal lengths.
Those of primary mirror with those of eyepiece (EP).
Therefore I guess that your EP has 12 mm focal length
not the aperture.

Now if we have settled this, another point has to be dealt with.
It is your use of word "aperture", like in:

>Commercial ccd's like starlight are at 3 mm and 5 mm
>apertures. 

Usually we speak about area of the CCDs not aperture. In this case
3mm square or 5mm square. Sometimes the diagonal of the
rectangular array is mentioned. 
Word aperture is reserved one in optic and must not be associated
necessarily with physical object ( eg aperture stop).

As you confused aperture of the EP with its focal length than
proceeding with calculations based on this assumption
that is using CCD area ( aperture) in the same way as EP focal length
 you have got a big problem like this one:

>My idea is if one could fashion an array of ccd chips
>say 2 across and 2 deep that would be around a 4mm
>aperture which would yield 187.5x with my scope of
>750 mm focal length.

This calculation will be OK if mentioned 4mm will be
a focal length of the used EP. Area of the CCD put 
at the focus of the primary mirror has nothing to do
 with magnification. It can influence it in no way.
You may have bigger or smaller field of view (FOV)
by changing the CCD area,
but at the same magnification.
To change magnification another optical element must be
introduced ( usually EP).

Regards
Vladimir.

PS
mentioning of interferometer in some replys was because
CCD registers only light intensity and not the phase
which would be needed to reconstruct the image
if objective will be replaced with CCDs as you
mentioned in your original post.


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