مرشح OIII 3nm محسّن لـ f/2.8-f/3.6

Shot a couple of emission nebulae last night at f/3 and the contrast against the sky background was noticeably better than with my old filter. The 3nm bandpass really isolates the OIII signal without cutting too much of the star field.

The 500.7nm line comes through so clean on my f/3 scope that the background sky just falls away, even with a nearly full moon up. The bandpass is tight enough that I don't get that washed-out haze on the edges of the image. Worth every penny for narrowband work.

I’ve been running this OIII filter on my f/3 scope and the contrast on the Veil Nebula is noticeably better than my old 6nm filter, especially with the narrow 3nm bandpass. It’s sharp even at the edge of my field, which I didn’t expect. Definitely worth it for narrowband imaging.