IDAS NB3 Dual Narrowband Oiii Sii anybody?

[900SL]

Hi

 

Anybody use the NB3 for OSC with the IDAS NBZ to get H O S?

 

Interested in how it performs, the bandpass is a bit wider than the NBZ

[Turix]

Rather late reply, so I don't know if this is still of use to yourself (although hopefully it'll help someone else if not)!

I've got an NB3 and use it for exactly what you suggest, SHO imaging with an OSC camera, combined with an l-extreme for Ha / Oiii. The best I can work out the band passes for both Oiii and Sii on the NB3 are rather wide, which doesn't appear to be widely advertised, I found the following chart whilst looking into the possibility myself:

This also shows quite nicely why the NB3 requires stacking with a second filter to remove the UV/IR wavelengths, I've been using an l-pro for this purpose because it has higher transmission at Oiii/Sii than my cheap UV/IR filter but I imagine something like an Astronomik L-3 would be a better choice.

Unfortunately due to the wider band pass of the NB3 compared to the l-extreme I find myself not using the Oiii from the NB3 when processing images, as it generally just reduces the SNR compared to the 7nm Oiii from the l-extreme alone. I imagine though if you were using the NB2 and NB3 together as "intended" by IDAS this wouldn't be an issue. For this reason I've been tempted to switch to a dedicated 6-7nm Sii filter instead, although I did notice recently that since I bought my NB3 Askar have released a 6nm Oiii/Sii dual band filter too.

https://www.firstlightoptics.com/narrowband/askar-colourmagic-2-6nm-oiiisii-duo-band-d2-filter.html

If you're interested in some examples I've got a few uploaded on my Astrobin account:

NGC 1499 / California Nebula (Starless SHO)

NGC 7635 / Bubble Nebula (SHO)

Melotte 15 / Heart of the Heart Nebula (SHO)

 

 

 

Edited November 30, 2022 by Turix

[900SL]

Thanks Turix, appreciated. It's kinda moot now IDAS have stopped the NB3 (out of stock everywhere). I'll look up the Askar as an option though

[jasonjeremiah]

Late to the party but hopefully this info will benefit someone.  James Thompson done a lot of extensive testing with virtually every filter used in astrophotography, including the IDAS filters.  I've attached the PDF copy of his study on all of the IDAS filters being made at the time, including the NB2, NB3, and NBZ.  His findings show the width of the Sii bandpass to be 18.5 and Oiii bandpass 21.  Their narrowest Dual Band the NBZ has a bit narrower bandwidth at 12 for Oiii and 10 for Ha.  

I use the Optolong L-Enhance in conjunction with the IDAS NB3 and have produced some very fine SHO images with the combo.  I disdained the L-Extreme and sold it after 2 imaging sessions.  I couldn't stand the massive halos around all bright stars.  I don't mind the extra bandpass width of the L Enhance and prefer it when using my really fast scopes, such as my Sharpstar or Hyperstar.  I do find the Oiii data from the NB3 to be weaker, but a big part of that is the narrower bandwidth in the Oiii.  I don't toss the Oiii data from the NB3, but will linear fit it to the L Enhance Oiii data and then combine them in PixelMath for my final Oiii channel.

TestReport-IDASFilterComparison_Nov2021.pdf

[900SL]

Thanks for that J.  I'm still on the lookout for an NB3. I'm very happy with the IDAS NBZ, no halo, excellent dual band filter in Bortle 7, no quality issues whatsoever.