Quote:
Originally Posted by Kos-Mos
The bigger the better
Larger is your apperture, clearer will be the image. That is all.
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Just to expand on that, it's a reference to Exit Pupil.
Aperture size / Magnification = Exit Pupil
so a 48mm scope / 13x mag = ~3.7
The maximum pupil diameter is, on average, about 7-8mm. An exit pupil > 6mm will give you a very bright image, even in low light conditions (i.e., what you're looking at will be brighter through the scope than not.)
~5mm is average. It will give you good clarity in daylight and low light.
Below 4mm what you see through the scope will be darker than through plain view. This makes low light use (or even looking into shade) impractical.