I’ve been working on a project, the Soap Bubble Nebula with my IDAS NBZ NB filter, 10nm for both Ha & OIII. With 3 hours of data with my 12” f5 newt in bortle 4 skies you can barely see the nebula while the 21-22nd magnitude central star is clearly visible going with 600s subs.
This filter has a 5nm spec for both Ha & OIII so I’m going to be interested in what 3hrs with the same conditions will produce with this filter. I found out about this filter from @manuelpeitsch in a discussion here: https://www.astrobin.com/01ok88/

I also got some info from @petermeyers about this as well.

I’ll post when I get the results!

Updated and Comparison images attached. Information about this comparison below.

The image I decided to test was PN G75.5+1.7 or better known as the Soap Bubble Nebula. I found this a difficult target to image even with my 12" F/5 Newt. When I 1st imaged it with my IDAS NBZ filter, I was surprised that I could barely see it zoomed in with 1 10 minute sub. While 3 hours worth of data allowed me to see it much better, I wondered if I could find a better filter that would work with my OSC, ZWO ASI071MC Pro. As mentioned above in a little conversation with Manuel, I decided to give it a try. This filter is $380.00 USD compared to 299.00 for the NBZ, but I thought if it provided a significant improvement it would be worth it.

Goal: I did not try to do anything other than basic processing, so it was as close to apples to apples comparison between the 2 filters.

Filter bandwidth:
The NBZ bandwidth is 12nm in both Ha & OIII
The Antlia bandwidth is 5nm in both Ha & OIII

Image Info:
I decided to shoot 3hrs worth of 600s subs with both filters. The 1st clear night with the NBZ the moon was close to 1st quarter in the western part of the sky. I wanted to try and get an apples to apples comparison (as close as possible) so I waited until I had similar conditions (moonwise) and that was last night 7/18/22 however the moon was in the eastern part of the sky. I was able to get the 3hrs of data with the Antlia ALP-T. I was very surprised that with just 1 - 10 minute sub, the bubble was clearly visible.
Processing:
I processed both data sets in APP and then took the integrated images of both files over to Pixinsight where I did the exact same processing to each image. My work flow is as follows:
1) Crop
2) DBE and then ABE afterwords
3) Background Neutralization
4) Color Calibration
5) EZ Denoise
6) EZ Soft Streach
7) SCNR 50%
8) Added text in Gimp
Results:
My personal opinion is I think there is a bit more contrast in the ALP-T image versus the NBZ. I'm not sure what's going on in the bottom right corner of the NBZ image, so if anyone can explain it, please do! I believe it's there in the ALP-T as well, but not nearly as noticeable as the NBZ. As I was processing the 2 images, I notice that before I did steps 3 & 4 above the soap bubble was quite a bit more, distinct. I decided to use these 2 images for the comparison because I felt most of us would use that process. As for the extra $80.00 more for the Antlia, I'll let you make that decision for yourself. In my case, I was looking to get another NBZ filter for a new wide field setup I'm working on, so the NBZ will be moved to that setup and the Antlia will take its role in my main rig.
Something else I'll bring up, when I was researching this filter there were a lot of comments about reflections on the brighter stars. While I was waiting for the moon to get closer to the phase that I shot the 1st set of data, I did a test on SH2-101 and found that there was indeed some halo's going on. Here is a pix of the 2 halos around the stars to the left of center I found to be apparent below.

I found a quick and easy "halo mask" that was able to help reduce them by Charles Bracken. If you're interested, you can find it at this link: https://digitalstars.wordpress.com/2019/10/27/tutorial-how-to-eliminate-star-halos-in-pixinsight/

I processed SH2-101 several ways. I'm still not super happy with the SHO versions but, you can see them here if you are interested: https://www.astrobin.com/1xcy6v/G/

When I did my research, I found a couple threads on Cloudy Nights about it, but not as much as I'd like to have found. I know in some cases $380.00 for a filter isn't a lot of money, but for me, it is, and I'd like to have seen more feedback on it. In the end, I hope some of you find this useful.

Thanks for looking!

Dale