A Couple of Bad Data Sets - Help Wanted

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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MarinerDNA
Posts: 5
Joined: Mon Nov 16, 2020 5:26 am

A Couple of Bad Data Sets - Help Wanted

Post by MarinerDNA »

Having a bit of trouble processing a couple data sets to something even remotely acceptable. The data is not good, especially with M81/M82. My tracking is usually better, but this time around DSS would only process 1 of 52 subs. I didn't want the session to be a waste and bought Astro Pixel Processor which stacked them without a hitch. I was hoping someone could do a quick process on them and list what they did so I can try it myself and see if I can get a similar image. I would learn much.

M81/M82 - I did pretty good with getting rid of the walking noise and gradients (best I've done so far). When I got to color...I couldn't get it looking like an actual galaxy. No matter what I did I could only get it showing one uniform color. Going by other photos of this target I've seen much better with less data (3 hr), worse skies (bortle 5) and a similar image train. Seeing and transparency were both average. Zero cloud cover. Edit: I tried this again today and couldn't get any color on Bodes. The Cigar I had to lasso the center to bring out that red. At least that worked.

The other issue I had was shrinking the stars and bringing out individual color in them. This area of the sky is rich in blue and red giants, but all of them remained white in my final image. Here's the FITS file (yes my flats could of been better): https://drive.google.com/file/d/1NIokLD ... sp=sharing


Heart Nebula - I didn't do bad here in some areas. I used some tips Ivo gave me on background and walking noise but had the same above issue with stars. Also I felt there was more Ha to pull out and maybe more depth to the heart itself. The night I imaged this my neighbor had all the Christmas lights on AND a spotlight flooding his backyard so there were these weird, yellow "gradient clouds," most of which can be cropped out or corrected. This was stacked using DSS; it's only 1.5 hrs of data.

Tiff file - https://drive.google.com/file/d/13XaeX9 ... sp=sharing

I'm not guiding yet, but I'm ready. My thinking when I started was to begin unguided for a few months to not overwhelm myself. Given that it's a new skill to learn, I can't imagine I'll have another new, successful data set to practice with until mid-late Spring. I'm getting closer to being able to process an image I'm not totally embarrassed showing. Ivo and some of the tutorials+these forums have helped a bunch. Thank you to anyone who gives these a look! :obscene-drinkingcheers:
Burly
Posts: 387
Joined: Mon Aug 31, 2015 7:06 am
Location: Northamptonshie uk

Re: A Couple of Bad Data Sets - Help Wanted

Post by Burly »

Hi i had a go at bodes data ,data has poor focus which when you compare to the heart data you can clearly see the difference ,i would suggest aquiring a bahtinov mask as a must then if funds can stretch an autofocuser make life easier , Dithering with a dslr is a must and will eradicate walking noise imo,also temperature changes will affect focus so refocus every 2 degree change ,
so i advise to get guiding asap dont be scared of it it is not that bad to set up what is your setup scope camera /mount etc ,i use APT and you can set that up to dither between frames ,also make sure you take flats ,bias and Darks though if you dither you can do away with Darks ,so make a bias library and take flats on the night every time you image ,also try for at least 4hrs of data the more data will make life easier to process ,there was a dust bunny on the heart that would calibrate out with flat frames ,or maybe take camera to a photography shop for cleaning if it gets to bad ,but flats are a must ,Heart nebula seems ok you can see focus is fine just get more data
2 heart_Easy-Resize.com.jpg
2 heart_Easy-Resize.com.jpg (94.5 KiB) Viewed 1677 times
Dust bunny was eradicated using the heal module ,just make a mask and using lassoo draw around bunny and heal will magic it away ,adjust neighbour hood samples to suit .
workflow txt in dropbox link
https://www.dropbox.com/s/4ohihqc0onkqj ... e.txt?dl=0
Attachments
Bodes_Cigar-RGB-session_1_Easy-Resize.com.jpg
Bodes_Cigar-RGB-session_1_Easy-Resize.com.jpg (85.4 KiB) Viewed 1677 times
MarinerDNA
Posts: 5
Joined: Mon Nov 16, 2020 5:26 am

Re: A Couple of Bad Data Sets - Help Wanted

Post by MarinerDNA »

Thank you @Burly for taking the time to look through those rough data sets.

Looking back at it, yes, I know what happened with the focus on Bodes. My original target was Orion but my mount wasnt cooperating. By the time it started working (after a re-do on the PA) Orion flew out of view. Bodes was my backup but I forgot to do another focus with the Bahntinov mask. Maybe out of frustration. Because that was probably my last chance to get that target (my favorite).


If I'm not guiding is it still possible to dither? I'm using Astrophotography Tool but it looks like the dithering function (unguided) is primarily used for premium mounts? Google searches havent helped me answer that for certain.

The dust bunny...yep that same dust bunny has been in the last 3 images. I take flats and bias, so I'm worried there's dust stuck in the sensor. It wasnt there until I got my camera back from Life Pixel (Ha mod). I've tried to hit everything with pressurized air but its still there. Did you see it on the Bodes photo? Its hard to tell.

Thank you for that Heal tip. When I look at your work-flow in the dropbox l will definitely practice this!
Burly
Posts: 387
Joined: Mon Aug 31, 2015 7:06 am
Location: Northamptonshie uk

Re: A Couple of Bad Data Sets - Help Wanted

Post by Burly »

If using APT yes you can dither,go into settings in dither tab can’t remember the option think it says apt dither assuming you can connect to mount via ascom , have a read of apt manual it will be in there , not sure what dither distance to choose, maybe 4 to start with see how that works , didn’t notice on bode for bunny maybe lost in noise maybe flats not correcting properly I usually have histogram half way on my d5300 seems to work 1/10 sec for me .
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