What are the costs and benefits of many short
exposure images over fewer long exposure images ? Of course tracking
issues are an obvious one.

A long exposure will be blurred because of seeing conditions.
Very short exposures freeze the "ripples" from the atmosphere.
If you get enough and stack them you can eliminate most of the
problems caused by viewing through the atmosphere. This is why
amateurs today produce better moon and planetary photos than
the pros did a few decades ago.

Clear Skies

Chuck Taylor
Do you observe the moon? If so, try
http://groups.yahoo.com/group/lunar-observing/

If you enjoy optics, try
http://groups.yahoo.com/group/ATM_Optics_Software/
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