Hi Ray,
Well I think I get it !
So a larger Image circle is simply the scopes greater ability to see more of the sky at the same focal length ?
The image scale will of course remain the same !
So a given pixel receives much the same light as another one on a different system (with a different image circle), just that it can illuminate a larger imaging chip/plate/film.
So its capturing more light overall and making it useable, but not at the expense of a given pixel
So one scope must still be more efficient in terms of light gathering power even though
So it begs the question (at least for me) - Is F Ratio actually the FL divided by scope Aperture ? - Or is it focal length divided by some sort of "Effective" scope Aperture"
Or have I confused your F No. with F ratio ? - Maybe thats what I have done !
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