3nm Antlia Narrowband Filters

2 replies587 views
Kurt Zeppetello avatar
I recently upgraded my ZWO 7nm Ha and OIII filters with the 3nm Antlia Pro filters and could not be happier. I purchased the ZWO filters as part of a kit when I purchased the ZWO ASI1600MM 5 years ago. I have been very satisfied with the ZWO filters as the did their job for a relatively inexpensive price. However, as my processing improved my images seemed to reach a maximum detail/sharpness yet I suspect they could have been better. Since then Antlia introduced a 3nm Pro version of their narrowband and at a price that I could afford. Astrodon and Chroma existed but they were a little out of my price range. So how good are these filters? I made two YouTube videos which show the experiments and results:

Just How Good is the Antlia 3nm OIII Filter?  
https://www.youtube.com/watch?v=WJZ-KWoS-KY&t=11s

3nm Antlia Narrowband Filters - Part 2) Hydrogen 3nm vs. 7nm
https://www.youtube.com/watch?v=J0r3NkIawEs&t=5s 

Oxygen Comparison
I compared my new Antlia 3nm OIII Pro Imaging filter with my current ZWO 7nm OIII filter. Since I have an open position on my ZWO EFW, it was very convenient to make a good quality comparison. I hoped and expected the Antlia to perform better since it was 3nm vs. 7nm and I was not disappointed!

The experiment took place on 12-29-22 around 9 pm. I collected nine 5-minute subs of IC 410 using the ZWO OIII filter but only kept seven. I then switched to the Antlia OIII filter where I again collected nine 5-minute subs but kept eight. The temperature of the ZWO ASI1600 was set at -20 degrees C. 

Some the highlights:
- smaller stars including no halos around large stars
- increased sharpness and detail
- better nebula definition 


Hydrogen Comparison
I compared my new Antlia 3nm Ha Pro Imaging filter with my current ZWO 7nm Ha filter. Since I have an open position on my ZWO EFW, it was very convenient to make a good quality comparison. I hoped and expected the Antlia to perform better since it was 3nm vs. 7nm and I was not disappointed! 

The experiment took place on 1-16-22 around 9 pm. I collected three 5-minute subs of IC 410 using the ZWO Ha filter. I then switched to the Antlia Ha filter where I again collected three 5-minute subs. The temperature of the ZWO ASI1600 was set at -20 degrees C. No post processing was done on any of the images.

Some the highlights:
- smaller stars
- slightly increased sharpness and detail
- better nebula definition 

I plan on purchasing the 3nm Antlia SII filter in the near future. 
Lastly, no processing was done on any of these images except stacking!


Fig 1 - ZWO OIII


Fig 2 - Antlia OIII


Fig 3 - ZWO Ha


Fig 4 - Antlia Ha
Helpful Engaging Supportive
Tim Hawkes avatar
Hi Kurt,  very useful thankyou.  You have provided a nice practical answer to a question raised in this former thread https://www.astrobin.com/forum/c/astrophotography/deep-sky/how-much-improvement-does-a-3-nm-oiii-filter-provide-over-6-nm/

I have a 6 nm OIII filter and in theory (as KS_observer pointed out in the referenced thread) going to a 3 nm OIII should provide a 1.41 X improvement in SNR -- and your data seem pretty consistent with that expectation.

Improvement with the 3 nm HA filter is also definitely there too in your pictures.  Having an F4 and an F5 system  I think that the 3 nm OIII filter will work out so I intend to get one.   I will probably still stick with the 7 nm HA though because I do like to image HA in galaxies and 3 nm is too tight when you take into account the red shift.
Tim
Helpful Insightful Respectful Engaging
Kurt Zeppetello avatar
Thanks for the info Tim. In fact I was only planning on just the OIII for and waiting to get the Ha and SII over the course of the year. I believe you are correct with the 7nm and red shift on faster systems. Cuiv, the Lazy Geek has some videos on this very topic.  - Cheers Kurt
Related discussions
Chroma 8nm Ha, 5nm Sii/Oiii vs Antlia 3nm SHO 50mm round filters
I have made this post on CN but I also think it is worthwhile posting it here on Astrobin as it addresses a differene audience, and it might be useful for some here. I have recently moved to a full frame imaging setup to combine with the AG Optical C...
Jan 8, 2024
Both posts discuss astronomers upgrading or acquiring narrowband filters to improve their astrophotography image quality.
Need Help w/C8 - OAG & Starizona Corrector
To give a little background, I’ve been imaging now for about 3 years and have often used my C8/CGEMII with a 60mm guide scope with no real problems. I’ve often been warned about differential flexure and that an OAG was ideal for this focal length, wh...
Apr 16, 2024
Both posts discuss astronomers upgrading their equipment to improve image quality and overcome limitations they encountered with their previous setups.