Help with M104

Questions and answers about processing in StarTools and how to accomplish certain tasks.
mhamburg
Posts: 34
Joined: Mon Sep 08, 2014 12:40 pm

Help with M104

Post by mhamburg »

I am having some trouble getting through a workflow for M104. Without doubt I need lots more practice. I am including a link to the original .fts file -
20x120s @iso1600 with Canon 40D @ 2800mm. I am also including a .tiff file I played with in Irfanview. The colors seem off (among other things.) I appreciate all the help.
Michael :confusion-shrug:

https://www.dropbox.com/s/wqr6awk4mw83unc/M104.fts?dl=0
https://www.dropbox.com/s/ing3qv73c5jm3jb/M104.tiff?dl=0
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admin
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Re: Help with M104

Post by admin »

Hi Michael,

I had a look at your data (thanks for uploading!)
To me, something doesn't seem quite right - to my eye there appears to have been some sort of pre-processing filtering applied... (and at the very least it has been pre-color balanced) How did you stack the CR2s? Did you use any other software in between putting them through the stacker?

In general, have a look in the new website/documentation on the various ways you can colour balance your data and what to look out for.
The 'Band' module will also help you somewhat with ameliorating the horizontal banding.
Ivo Jager
StarTools creator and astronomy enthusiast
mhamburg
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Re: Help with M104

Post by mhamburg »

sized_M104.jpg
sized_M104.jpg (11.16 KiB) Viewed 7702 times
So I kept running and rerunning my data through StarTools until I got something that looked better than a bad picture on a 1950 television. It really takes a lot of experimenting to make improvements. Here is a resized sample of M104. I think that I need longer subs and more of them. Thank you Ivo for all your support.
Michael
Rowland
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Re: Help with M104

Post by Rowland »

Hi.

How did you preprocess your subs?
mhamburg
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Re: Help with M104

Post by mhamburg »

I ran them through DSS.

Michael
Rowland
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Re: Help with M104

Post by Rowland »

Can't download the fits file. Not present it says? Can you upload again, please?

The pixel values in your tiff are very low. The figures displayed approximate dark frame values from my DSLR. I think the data is clipped. Not unusual with DSS from what I can see. Maybe some of the other users can point you to the correct settings, but I recommend you change your preprocessing method. It will make a world of difference. Hope this is in the right direction. Looks like a great image.
Attachments
M104.jpg
M104.jpg (23.66 KiB) Viewed 7671 times
mhamburg
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Joined: Mon Sep 08, 2014 12:40 pm

Re: Help with M104

Post by mhamburg »

Hi Rowland,
Let me try a link to the .FTS file in Dropbox. I would surely appreciate how to fine tune these settings. Thanks.
Michael
https://www.dropbox.com/s/wqr6awk4mw83unc/M104.fts?dl=0

Update: I have just attached a resized (in BD Sizer) version of one of the original light raw files Maybe thiis can be of help.
sized_LIGHT_120s_1600iso_+13c_20150418-23h08m29s716ms.JPG
sized_LIGHT_120s_1600iso_+13c_20150418-23h08m29s716ms.JPG (232.27 KiB) Viewed 7667 times
almcl
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Re: Help with M104

Post by almcl »

I'm certainly no expert, but looking at the FITS file, there seems to be an issue with either focus or misting in the optical train somewhere. I've not personally seen an effect like that in the screen shot below but the Maltese cross effect around the brighter stars prompts me to ask what focussing method you use?
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focus or dew.jpg
focus or dew.jpg (20.03 KiB) Viewed 7665 times
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
mhamburg
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Re: Help with M104

Post by mhamburg »

Capture and focus was done with BYEOS using the lowest FWHM (Full Width Half Maximum) value I can get.
Michael
almcl
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Re: Help with M104

Post by almcl »

Unlikely it's a focus issue then, any chance there was dew or mist on any part of the optical train? (Clutching at straws a bit, I admit!)
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
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