
Originally Posted by
Steaphany
Dave,
Shoot as many as practicle. One of the areas that's grown significantly with amateur astrophotography is to adapt a video or even a webcam style camera to a telescope and video the sky. The stacking software will read video files, extracting each frame, align and stack it all.
Another area where professionals operate is to stack collections of exposures from several nights of observations.
As you can imagine, whether you just shoot 8 or 8,000, it's all up to you and the results that you are after.