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Homemade ETX Back Focal Reduction / Projection system & C-Mount adapter

Note: Since the weather was cloudy (as usual!) and I wanted to work on the system, I focused on the first thing that caught my eye, a digital clock across the room which unfortunately was NOT parallel to the objective of the scope resulting in less than perfect focus across the field of view which became more obvious as the magnification was increased.


PC164C + Widefield scope
at 16 & 160 mm for comparison


PC-164C CCD on ETX-90 back
at ~0.4 fl ~500 mm. (F ~5.6!)
Reduction is adjustable and this is about
the shortest practical f/l for this scope.


PC-164C CCD at Prime Focus ETX-90 back


PC-164C CCD on ETX-90 back
at ~2 fl or ~2500mm
ETX-90 back - Magnification is adjustable!


Homemade ETX back to C-Mount adapter
This can be built for ~$5
Construction details SOON!

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< Homemade C-Mount
variable focal reduction / projection

< PC164C for size comparison

< $5 1.25 inch to C-Mount adapter

System can also be configured for projection

Construction details SOON!

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