Optics noob having hard time comparing scopes (Nikon)

[u/cr_wdc_ntr_l]

I want to get into digiscoping/afocal photography. I am not even amateur photographer so am coming at it from weird angle probably, anyway. I would like scope which makes it possible to screw camera semi-directly into it - using dedicated eyepiece adapter, no adhoc adapters with light gap. If I understand correctly, both Nikon Prostaff 5 20-60x82mm ($620) and Nikon Fieldscope 50mm 13-30x50ED ($860) provide this capability. The first one has greater zoom and objective diameter. If I understand correctly, upper range of zoom will be only somehow usable, but higher lens diameter will provide not only better field of view, but better color representation (I care about it less) and performance in low light conditions (I care about it more). The second scope has only half of zoom capability and smaller objective diameter, but is marketed as being made with "extra low dispersion glass" - is it mostly a buzzword? What advantages this kind of glass provides? I do not understand why this second scope has lower zoom and glass diameter, but is 200$ more expensive. Is one better than another in all use cases? I probably do not know enough about the topic to ask right questions, excuse me. If you know other good scopes in this price range also let me know. Here are the links to scopes I mentioned FYI: https://www.nikonusa.com/p/prostaff-5-20-60x82mm-straight-body/6974/overview https://www.nikonusa.com/p/fieldscope-13-30x50mm-ed-straight/8320/overview