You recommand, for some object to observe, to use filmer (Red loupe). Do we need to add an external filter? In that case what régence? Or we need to use the filter of the seestar S50 ( duo band H alpha/OIII) Thank you in advance for your answer. Best regards
Filter needed
Under normal circumstances, you don't need additional filters. The built-in H-alpha/OIII filters of Seestar S50 can already meet the requirements for deep-sky astrophotography. If specialized observations (such as for planets or the sun) are needed, then corresponding external filters should be purchased. (We have provided a solar filter.)