Tightest highspeed or f/2 dual band OSC filter?

Filters Duo-Narrowband One-Shot Color
3 replies•82 views
Phil Creed avatar
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

Well Written Engaging
andrea tasselli avatar
andrea tasselli avatar
ALP-T Highspeed.
Aris Pope avatar
Aris Pope avatar

Antlia ALP-T Highspeed

Phil Creed avatar
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

Helpful Engaging
Related discussions
Whats your recommendation for a dual narrowband filter on a fast f/2 system?
I run an Asi2600mc OSC on my EdgeHD with an Hyperstar v4 at wonderfully fast f/2. Unfortunately my L-Enhance creates really massive star halos, so I look for a better dual narrowband filter on my f/2 system. Any experiences with L-Extreme F2 or recom...
Discusses dual band filters for fast f/2 systems; relevant to author's equipment setup.
Nov 21, 2024
Dual Band Filter Discussion
I am looking at getting into nebula imaging more and want to get a good Dual Band filter. I am using 2 different OSC cameras the asi533mc and as asi2600mc duo. I am basically in a bortle 7 I have a ZWO dual band filter but it gets halos on all my sco...
Addresses dual band filter performance on fast scopes, directly relevant to halo issue.
Apr 16, 2025
Stuck on Next Steps for My Astrophotography Setup – Need Input!
Hi everyone, I’m looking to upgrade my astrophotography setup, but I’m torn between several options and would love to get your expert opinions! PS: I dont intend to turn this into a yet-another OSC vs mono debate Just a recommendation on options, alo...
Filter and camera configuration advice applicable to author's imaging system.
Jan 26, 2025
Thoughts on the Samyang 135mm f1.8?
Hello everybody, so ive been slowly putting together a wide field rig for Milky Way shots, but I also would like to have a 135mm lens that I can pair up with my Sony a7ii astro modified camera. now I thought about going with the famous rokinon 135mm ...
Discusses 135mm f/2 Samyang lens with dual band filter setup.
Jul 28, 2024
D2 experience with fast optics (f/2.2)?
Im looking for a sii/oiii dual narrowband filter specifically for a Hyperstar 9.25 v4, and unfortunately options are pretty slim. From the ones available it seems only the askar c2 and d2 are realistic, and the c2 seems to have a very wide bandpass. ...
Discusses narrowband filters for fast optical systems similar to yours.
Aug 4, 2025