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Old 06-08-2020, 04:39 PM
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The_bluester (Paul)
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Join Date: Feb 2011
Location: Kilmore, Australia
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If you are undersampled, smaller/dimmer stars will appear blocky and pixellated, you would be able to extract some extra data by drizzle processing but you need lots and lots of subs to keep noise under control.

Over sampling on the other hand will result in the stars covering a lot more pixels and probably star edges and fine features being well resolved, but beyond the limits of the seeing you are just making things bigger, not getting more detail, it also costs you in extra file size per sub. As the light from any star or feature falls on more pixels, you may also require longer exposures to get the same values.

I used an ASI294MC Pro on an Evostar 72mm with the 0.85 reducer/flattener and it performed pretty well, but if yours is an Evostar 72 you possibly need a filter (I bought a ZWO one marketed as an IR filter, but the specs suggest it is more like just a luminance filter with cutoff at the near IR and near UV points) or you are liable to have problems with reflections. Some of the newer cameras have the UV-IR cut filter incorporated in the sensor chamber window now which saves adding an external one.
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