Brendan,
Not sure how you can come to that conclusion without some very different assumptions to the OP's.
It depends entirely on what the intended use is, his is Deep Space not Solar System
Given the OTA is a 90mm f5.5, meaning its a widefield scope at roughly 500mm as opposed to 1800-4000mm
Trying to achieve 1 arc sec per pix would require a camera with 2.5um pixels.
That would result in extremely poor dynamic range, high noisde and low well depth - not at all suited to DSO astrophotography, not to mention the field of view would likely be small
A popular AP combination that will repeatedly and reliably produce stunning widefield astrophotos is the FSQ106 and STL11000 and that is at an image scale of 3.5arc secs per pixel - I am not suggesting that camera here ! - just illustrating that a larger image scale is popular amongst many highly competent astrophotographers who aren't necessarily interested in getting the maximum resolution that a terrestrial scope could provide.
Given he is also using an EQ3 mount, it would be difficult to track at under at 1 arc sec anyway and that makes it a much more suitable candidate for a large image scale to even out the errors in seeing and guiding.
Regards
Rally
Quote:
Originally Posted by bmitchell82
. . .
What you want to do in a perfect world is get 1 arc sec per pixel.
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