Tightest highspeed or f/2 dual band OSC filter?

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Phil Creed avatar

I currently have a 135mm f/2 Samyang and a RASA8 is always a tempting thought at the back of my mind.

I have a dual band filter for my 533MC-Pro, an IDAS NBZ-II. The IDAS NBZ-II seemed like the logical solution for me since it’s tighter than my prior filters (NBZ-I and, earlier, L-Enhance) but still works on face-peeling, screaming-fast systems. And for budgetary reasons, a single-filter option that works on my 135mm f/2 lens and my f/4.8 AT60 (w/0.8x) and f/5.4 NP101 seemed the best option.

But if I decided to go the route of an L-Ultimate (or similar) for my refractors and an even tighter filter for f/2, what’s the tightest f/2 filter option out there for OSC?

Clear Skies,

Phil

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andrea tasselli avatar
ALP-T Highspeed.
Aris Pope avatar

Antlia ALP-T Highspeed

Phil Creed avatar

Looks like I’ll give the LPT High speed a look.

Here’s what I got so far using the original NBZ, which had 12nm bandpass on both H-an and O-III with a 533MC-Pro and 135mm f/2 Samyang fully open after 15hr 25min.

I figure the NBZ-II I now have (10nm H-a + 8nm O-III) will draw out the Squid more. It’s just it took a LLLLOT of time to squeeze out the Squid at a screaming-fast f/2, so if I could eventually get even tighter filter bandpass, I’ll go for the best I can get at that speed.

FB+Squid P3.5.png

Clear Skies,

Phil

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