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Process my data! Just over 3 hours on the Rosette

astrophotography imaging
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#1 Scdouglas

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Posted 21 January 2020 - 11:34 AM

Hey all, I've just started to get into more advanced processing techniques and wanted to see what everyone else could do with this data. It isn't the greatest data ever taken so I've also provided darks, bias, and flat frames to go along with the lights. 

 

For some background on the data it was taken over the course of 3 nights from my backyard. You'll notice the intense field curvature on the right hand side of every image, you'll also notice almost all of them are framed to the left side lol. Each frame is 5 minutes at ISO 1600 using my modified Canon 600D. You'll also notice the huge dust motes on the sensor, for the most part they can be ignored they come out completely with the flats I provided. Overall I hope this could be fun for some of you seasoned photographers as this data should be a little bit more of a challenge versus perfect clean CCD data from an expensive apochromat. I shot these with an Explore Scientific AR102 with no field flattener which I think is pretty evident lol. 

 

Here's the link to the google drive with all the files: https://drive.google...Cth?usp=sharing

 

If you need any more information I'm happy to provide it I'm just interested in seeing how far the data can go in hands much more skilled than my own. 

 

Clear skies! 



#2 Jim Waters

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Posted 21 January 2020 - 11:44 AM

Have you tried to process the data set yourself?


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#3 Scdouglas

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Posted 21 January 2020 - 11:47 AM

Have you tried to process the data set yourself?

Yeah I have my own process of it. I've been processing and reprocessing all day and at this point I think I have 4 or 5 different versions, I'm just curious to see what other people can do with it. I'm fairly new to processing data and I've been learning pix-insight but obviously more experienced people will be able to do a lot more than me with this data, so I just want to see how far it can go. 



#4 Mert

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Posted 21 January 2020 - 01:17 PM

Did you only use pixinsight? I mean preprocessi g, stacking etc?

#5 Scdouglas

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Posted 21 January 2020 - 01:27 PM

Did you only use pixinsight? I mean preprocessi g, stacking etc?

I started using pixinsight for one of my earlier processes but it came out too noisy. I think I was just expecting too much as I had processed in pixinsight trying to get the hubble palette to come through. I used an L-enhance filter to gather all the data but the pixinsight process looked far worse than my photoshop process. I did do the pixinsight process with less data so I think it would come out better now. I always use deep sky stacker for my stacking and calibration. 



#6 DuncanM

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Posted 21 January 2020 - 02:03 PM

 

This is straight from Astroart 7's preprocessing tool:

 

 

 
 

I used 6 flats, 6 bias, to save download time, 10 darks and all lights using an Average for light frame stacking.  No other processing.

 

It might help if you mark your camera's rotation position so that you can return to it accurately, and to use plate solving to accurately centre the target before each imaging run.

 

Edit: I'm using a rather poor monitor, and I may have blown out the reds a bit whilst preparing the jpeg.


Edited by DuncanM, 22 January 2020 - 12:40 PM.

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#7 Jim Waters

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Posted 21 January 2020 - 02:06 PM

I just did some "quick" PixInsight processing.  In doing STF stretching its obvious that the image was captured over multiple nights.  I count 3 overlapping sequences of Light subs in the rejection_high and low STF stretch. To eliminate the overlapping sequences of Lights learn how to do plate solving so you can go back to the exact position across multiple nights....  Also do NOT rotate the camera across multiple nights...

 

It looks like your scope has significant distortions towards the right and lower right per the image.  Or it could be from a tilt in 600D sensor and/or camera.  You need to look into this.  I am not sure why the image is green.  I used a new release of WBPP that was released today.  I used RGGB and VNG.

 

More later.


Edited by Jim Waters, 21 January 2020 - 02:18 PM.


#8 Scdouglas

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Posted 21 January 2020 - 03:06 PM

I just did some "quick" PixInsight processing.  In doing STF stretching its obvious that the image was captured over multiple nights.  I count 3 overlapping sequences of Light subs in the rejection_high and low STF stretch. To eliminate the overlapping sequences of Lights learn how to do plate solving so you can go back to the exact position across multiple nights....  Also do NOT rotate the camera across multiple nights...

 

It looks like your scope has significant distortions towards the right and lower right per the image.  Or it could be from a tilt in 600D sensor and/or camera.  You need to look into this.  I am not sure why the image is green.  I used a new release of WBPP that was released today.  I used RGGB and VNG.

 

More later.

Yeah I've been trying to figure out the shift issue for a bit now but I have no idea how to go about fixing that on the sensor if it is the camera. The images that don't overlap correctly were just me forgetting to run my plate solver on NINA to get them lined up exactly. I've attached the process that I did and honestly I don't think it looks too bad. The image shift I did manage to reduce in photoshop with a darken blend mode and then nudged a small corner of the image to realign the stars somewhat, which seemed to work ok. 

 

Here's my process, it was too big to upload it directly to CN: https://drive.google...iew?usp=sharing



#9 Jim Waters

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Posted 21 January 2020 - 03:30 PM

 The images that don't overlap correctly were just me forgetting to run my plate solver on NINA to get them lined up exactly.

Be sure you don't rotate the camera body between multiple nights.  Check for focuser slop, droop, wiggle, tilt ...etc.



#10 Mert

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Posted 21 January 2020 - 03:33 PM

I'd like to give it a swirl but Googledrive takes for ages to prepare the download.

Oh well, ….

 

Ah, finally I see some progress in the download, have to wait some more.....


Edited by Mert, 21 January 2020 - 03:34 PM.


#11 Scdouglas

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Posted 21 January 2020 - 03:42 PM

Be sure you don't rotate the camera body between multiple nights.  Check for focuser slop, droop, wiggle, tilt ...etc.

 

Yeah I marked my tension screw on my focuser so I know where to rotate the camera to so hopefully that issue gets mitigated significantly. As for the focuser slop I would put money on there being slop to some degree. Due to budget restrictions the refractor I use is an achromat that wasn't designed for imaging so I'd gamble that the focuser isn't really up to the task. As for the sensor tilt I have no idea how I'm going to go about solving this issue. The problem I see is that my refractor definitely has some degree of field curvature on its own so using that to measure tilt is a terrible idea on its own. There's also the issue of actually going about solving it. As I understand it I have to disassemble the camera and there are screws to raise and lower the sensor on each corner, since my tilt is seems to be almost entirely on the right side of the image I'd be looking at raising the left side of the sensor. Another issue I'd have to solve is whether to raise or lower the sensor and as I understand it with that is I focus a star in the center of the frame and then move it to the corner and if it defocuses in specific ways that determines whether to raise or lower the sensor, this is where I'm lost. I'll have to look into it more significantly to get this right because the tilt really does bother me in processing. 



#12 Jim Waters

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Posted 21 January 2020 - 03:49 PM

As for the sensor tilt I have no idea how I'm going to go about solving this issue. The problem I see is that my refractor definitely has some degree of field curvature on its own so using that to measure tilt is a terrible idea on its own. 

Star to debug the optical train.  Take a number of Light subs along with Darks and BIAS.  Rotate the camera 90 plus degrees and retake the Light subs.  Process the images in two batches.  If the distortions follow the camera rotation its the camera.  



#13 Scdouglas

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Posted 21 January 2020 - 03:57 PM

Star to debug the optical train.  Take a number of Light subs along with Darks and BIAS.  Rotate the camera 90 plus degrees and retake the Light subs.  Process the images in two batches.  If the distortions follow the camera rotation its the camera.  

Well it's supposed to be clear so I'll give that a shot tonight. I did run the image through photoshop's camera raw distortion settings and it seems to just have severe barrel distortion on the bottom right becoming more minor as you move up the right side of the image, not sure if that says anything about the underlying issue. 



#14 Mert

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Posted 21 January 2020 - 04:51 PM

Ok, now I see, just processed quickly and indeed there seems to be

quit some severe tilt somewhere in the optical train.

It seems as if the right hand side of the image is farther or closer to

the sensor then the left hand side.

Also some frames are rotated a bit with respect to others.

 

Just for fun, here is my quick go at it ( others will do far better

then I can! )

Thanks for letting me play with your data!!

Attached Thumbnails

  • Rosette-APP-Pix-CN.jpg

Edited by Mert, 21 January 2020 - 04:52 PM.

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#15 Jim Waters

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Posted 21 January 2020 - 05:06 PM

Ok, now I see, just processed quickly and indeed there seems to be

quit some severe tilt somewhere in the optical train.

It seems as if the right hand side of the image is farther or closer to

the sensor then the left hand side.

Also some frames are rotated a bit with respect to others.

 

Just for fun, here is my quick go at it ( others will do far better

then I can! )

Thanks for letting me play with your data!!

What SW did you use?



#16 Jim Waters

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Posted 21 January 2020 - 05:07 PM

Well it's supposed to be clear so I'll give that a shot tonight. I did run the image through photoshop's camera raw distortion settings and it seems to just have severe barrel distortion on the bottom right becoming more minor as you move up the right side of the image, not sure if that says anything about the underlying issue. 

My money is on lens cell barrel distortion.



#17 Scdouglas

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Posted 21 January 2020 - 06:41 PM

My money is on lens cell barrel distortion.

Ok so a quick update on the defocused side. After taking it out it seems thefront lens element was out of alignment. I don't have a collimation tool so I spent 20 or so minutes messing with it and I managed to get the right side looking much better than it did but still not perfect. I'll be getting a collimation tool to more scientifically fix this in the coming days but this issue seems to be solved. I included a quick plate solving frame from tonight so you can see the difference. Never thought it would've been collimation for a refractor but here we are. 

Attached Thumbnails

  • Capture-min.jpg


#18 Jim Waters

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Posted 21 January 2020 - 07:15 PM

This is good news...waytogo.gif  Post some updated images later...


Edited by Jim Waters, 21 January 2020 - 07:15 PM.


#19 deepanshu29

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Posted 22 January 2020 - 03:08 AM

Here is my take on your data. Like other have mentioned, you have tilt in your imaging train, otherwise your data is pretty decent. 
 
MasterLightDrizzle1x_lowRes.jpg

Edited by deepanshu29, 22 January 2020 - 05:01 PM.


#20 Kevin Ross

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Posted 22 January 2020 - 04:05 AM

And just for fun, here's my version. Stacked and mostly processed in APP, some finishing touches in PS. This is literally about 10 minutes of processing, after the stacking finished.

 

St-avg-12000.0s-MWC_1_3.0_none-x_1.0_LZ3-NS-full-eq-add-sc_BWMV_nor-AAD-RE-noMBB-mod-lpc-cbg-St.jpg



#21 Mert

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Posted 22 January 2020 - 10:31 AM

What SW did you use?



#22 Mert

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Posted 22 January 2020 - 10:32 AM

Hi Jim, I uzed APP for preprocessing and stacking, after that a quick stret h with Pix

#23 George Simon

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Posted 22 January 2020 - 12:23 PM

Here's my rendition, stacked with DSS and processed with StarTools, with a final tweak to color in GIMP. I have been laid up for a week now with a bad respiratory virus, so it was fun to have some data to work on. Thanks for making it available.

 

Stacked.jpeg



#24 Scdouglas

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Posted 22 January 2020 - 12:33 PM

This is good news...waytogo.gif  Post some updated images later...

Thought I'd post an update. Shot some more flaming star data last night and even though I used old data with the refractor out of collimation the new data did help fix some of that tilt. You can see in the bottom right that the old data is causing almost a weird smearing effect which noise reduction helped to get rid of but it's still there. I think after I get some more data I'll dump the old frames and just use the corrected ones. Came out pretty well though I think. 

 

Here it is, let me know if the link is broken: https://photos.app.g...9Gttoh4k9LPgZA6




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