What are the thread sizes on Lumicon filters?
The 1.25″ filters employ industry-standard 1.125″ x 42 tpi threads (except for Questar/Brandon, which use a thread pattern unique to Questar). The 48 mm filters employ industry-standard 48 x 0.75 mm threading, which thread into 2″ eyepieces. All larger filters use the given size with 0.75 mm pitch (e.g. a 72 mm Minus Violet filter has 72 x 0.75 mm threads).
