Combined Narrowband Filters - Forums

Topic starter

Oct 28, 2018

I am seriously consdering getting hold of either the STC Duo Narrowband or OPT Triad filters for use with my ZWO ASI071MC Pro OSC camera. I am located in Manchester, UK and have to deal with serious light pollution. Currently using the IDAS D1 LPS filter and looking for the next level of improvement but not ready for mono camera + full set of narrowband filters yet.
Does anyone have any experience with either of these filters? Is there much benefit from the slightly wider transmission band in the OPT filter?
Many thanks, Dan

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Adel Kildeev

Oct 28, 2018

Why bother if you keep color camera? No sense for me

Kevin Morefield

IOTD Staff

Oct 28, 2018

I use the STC Duo when I shoot with my OSC camera in the city. It works well but of course not as well as Mono with very narrow bandpass. The tighter bandpass of the DUO should be superior as the more light pollution needs a smaller bandpass to improve contrast. You will find that the Ha comes through pretty well but the OIII is a challenge. It will work on stronger OIII sources but on dim ones not so much. My 5 and 3 nm Astrodon filters I use on my mono camera work much better than the 10 nm bandpass of the Duo.

I've uploaded a couple of shots taken with the Duo from the City.

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Daniel Tackley

Topic starter

Oct 28, 2018

Adel Kildeev:
Why bother if you keep color camera? No sense for me

These two filters are effectively both Ha and OIII in a single filter and are therefore designed for use with a colour camera. I know you don't get the extra resolution of a mono camera but you are basically doing narrowband imaging, with all of its benefits, in a single pass.

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Siegfried

Oct 28, 2018

I use simply my Castell UHC Filter. But you need a UVIRCut filter too. The Castell let pass simply O-III at 500nm and H-alpha…..

Siegfried

Philippe Renaud

Apr 3, 2019

Hi
I also use the STC duo filter with an A7S defiltered and 2 different telephotos , Samyang 135mmF/D2 and Canon 300mm F/D 4 L ; it works pretty well with both lenses even under quite severe light pollution environement
I fully agree with Kevin about the comparison with narrow band filters and Mono Camera, far better results from the latest.

kind regards

Chris Vaughan

Jul 4, 2019

I love this filter on an OSC camera. https://www.astrobin.com/413163/