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Hi! I've recently acquired a new Astromodified Canon rebel XT and I've tried to take pictures of nebulas using it but I've noticed that there are these weird black artifacts that keep appearing in my images. Would like to know if anyone has experienced this before? Or are these dirt/dust specs on the camera, filter, and telescope glass? I've attached some of my edited and raw pictures for your reference. The black artifacts can already be seen in the raw image of the horsehead nebula and after stacking I think it got amplified. Anyway, advance thanks and I hope everyone's doing well.
I am wondering if anyone has a suggestion that might help me
My imaging set up is an RC reflector with an FLI proline 16803 camera and 50mm Astrodon filters (LRGB + 5nm narrow band)
I have had a string of issues...everything from my mount had mechanical problems to my telescope had issues with the mirror cell to some family distractions...but at long last I seem to have everything working with the exception of the Astrodon Ha filter.
Attached are representative 30minute subframes of the horse head and Pacman nebulae in Ha, SII, and OIII. I get similar results with different objects although for bright, broad spectrum targets like M42, I will get data from the Ha filter (much as the stars shine thru on the HH and Pacman) although even that data does not comport with other imager’s Ha images of those objects. The LRGB performance appears to be normal. My hypothesis is that this Ha filter is defective, perhaps not centered on 656.3nm
I have contacted Astrodon and exchanged a couple of emails with Cary Chleborad seeking some help. At first he claimed there was no issue because with enough manipulation some data could be extracted from the Ha. Later, when confronted with the other narrowband frames and the obvious difference to the Ha, at first he ghosted me, but when I said I would ask other imagers for help, he responded with a new position stating that because of the way the filters are made and their robust quality processes, it is impossible for the filter to be defective and therefore something else must be at issue. He does not offer a suggestion of what might be the problem, nor is he interested in having me send the filter back for evaluation. Frankly, I’m more than disappointed given the premium I paid for Astrodon filters
All that aside, and taking Cary’s position at face value, does anyone have an idea of what might cause this behavior other than the filter? In a perfect world, does anyone live in the Austin, Texas area who would be willing to try my filter one night and see what they get with their equipment?
The attached link is to the raw, uncalibrated files right off the camera. I think a simple blink process in PixInsight will show what I’m talking about.
I’m a little at my wits end, please help!
To celebrate the 25th anniversary of Sir Patrick's DSO catalogue, I've added the available Caldwells to my basic Marathon search sequence.
Those interested may be pleasantly surprised by how many of the additional treasures are only a short hop from a given (or en route to the next) Messier.
The sequence for 40°N can be found at the SEDS Messier Marathon homepage or at my blog.
So, although I had some issues with my auto guiding (which I found out afterwards) I did manage to get 9x180s exposures and 5 darks of Andromeda and give both stacking (using DSS) and processing (using GIMP).
My first attempted DSO....
I am pretty sure that people could get far more information out of the TIFF file from the stack.
Hopefully I will get another clear night soon. I am in a heavily light polluted area so I do have a clip in filter on my DSLR which I think took a lot away.
More practise needed!
Hi all, my second attempt at imaging over multiple nights, captured 60 mins Ha and a couple of 5 mins on Oiii and Sii on Christmas evening, then added more Oii and Sii on the 30th
Total of 60 mins Ha 25 mins Sii and 30 mins Oiii
Hubble mapped - SII,Ha,OIII = R,G,B. The Oiii data was very noisy but I'm fairly happy overall, also the ZWO Oiii filter caused a massive ring around Alnitak when stretched !
Comments welcome, I know it needs more data and I will need to learn to be more patient but the year is running out 🙂
Thanks for looking and have a good 2020.