----------------------------------- iosif 09 Aug 2017 16:23 ----------------------------------- Arata bine pe fiecare filtru. La mine albastrul are o diferenta de claritate. Posibil sa fie de vina si corectorul ff/fr. Am sa testez fara el. Salut. Cautam pe site-ul celor de la Astronomik, in vederea achizitionarii a doua filtre OIII si SII la 12 nm, si am gasit urmatorul aspect descris de catre ei, si care se confirma la testul facut mai sus cu focusarea pe fiecare filtru LRGB Typ 2 si Ha 12 nm in imaginile postate. Parfocal filters: All Astronomik Filters are parfokal! Due to the very small thickness-tolerance the focal plane is not shifted when changing filters! We have supplied parfocal filters for optical system as fast as f/1! MFR Coating: The 12nm Filters can be used on all instruments up to f/3, the 6nm filters up to f/4. (Filters for faster optics are available upon request.) Articolul complet. http://www.astronomik.com/en/fotografische-emissionslinienfilter/ubersicht-fotografische-emissionslinienfilter.html Cer senin Iosif.