[The ruling on sighting the crescent with magnifiers]

Answer—and Allah is the Granter of success: Sighting the crescent by magnifying and imaging devices is a sighting that is legally valid for fasting and breaking the fast, for magnifying/imaging equipment are merely instruments by which the presence of the crescent and its sighting become apparent. The instrument has no role in the existence or non-existence of the crescent, and it is not an instrument that creates the crescent’s existence.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1