Praise be to Allah.
The shar’i evidence indicates that people should not go to great lengths to sight the moon with these instruments; rather it is sufficient to sight it with their eyes. But if a person seeks the moon with them and is certain that he has seen it by means of them after the sun has set, and he is a Muslim of good character, then I do not know of any reason why his sighting of the moon should not be followed, because it is still a visual sighting and is not calculation. End quote.
Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him)