مرشح SII 3nm محسّن لـ f/2.8-f/3.6

The narrowband performance at f/3 is fantastic—finally getting clean SII data without halos around bright stars. Paired with my Ha filter, the nebula details really pop now.

Clear separation of the sulfur doublet at 671.6 and 673.1 nm, even at f/3.2, which surprised me—the stars stay tight and the nebula detail pops without halos. Definitely the sharpest narrowband filter I've used for dim emission regions.

I've been shooting the Orion nebula with my f/3 telescope, and the doublet lines at 671.6 and 673.1 nm come through clean without any halos. The contrast against the background is noticeably better than my old 5nm filter.