I started a post on flats issues that I had using my 36mm ZWO LRGB and NB filters that resulted in uncorrectable artifacts in my final images:
It turned out to be a very long thread with many post from interested parties. It has a huge amount of data in it and I highly suggest reading it in full if you are considering filter purchases or how to fix these types of issues. I am highly indebted and grateful for all the help, advice and commiseration from my friends here at Cloudy Nights. I think that this is a great example of how this community can work together to help us all out.
At the end of that thread I posted a set of data collected on the Alnitak region with the ZWO filters and my ASI1600MM-C camera with all the fixes for the hardware to get those filters working. At the end of the day, I was able to generate data that was basically clean enough to eliminate any filter-induced artifacts in my final images. It took a lot of time and effort, but this showed that the ZWO filters ARE usable with the proper masking and image processing. However, in the mean time, I had already bit the bullet and ordered a full set of LRGB, Ha, OIII and SII filters from Astrodon to replace the ZWO filters. In hindsight, I may not have made that purchase at the end since I was able to show that I could get good images. At the 36mm size, the Astrodon filters are ~3X the cost of the ZWO filters. I also had previously posted a thread asking what were the benefits of the Astrodon filters and were they worth the price premium. That thread also generated a lot of passion to say the least.
I have since installed and ran the Astrodon filters and collected an identical set of data on the same target of Alnitak. Since the previous thread was so long and I think that this comparison will be welcome, I am posting it in its own thread so that it is not buried in the other thread. I will post a link to this thread at the end of the long one. This is as direct an apples-to-apples comparison as I could do between the ZWO and Astrodon filters and for me is a direct answer to what you get for your money with Astrodon. I do think they are worth the investment.
Bare with me as I will take me some time to get all the data posted. I hope to have it done tonight.
Edited by cfosterstars, 16 January 2018 - 04:58 PM.