28 replies to this topic

[tjschultz2011]

I'm looking to have someone whose highly experienced in astro image processing try their methods on an image or two of mine. This would mostly be just for fun and to try and judge how my processing techniques are coming along since I've only been at this less than a year. I feel like my processing skills are fairly basic but my results have been pretty decent considering my unconventional setup. I image with a modified 17.5" f4.5 dobsonian tracking with ServoCAT and I can manage 20 second exposures on a good night but usually 10-15 is what I stick with. I stack in DSS and process in Photoshop 2020. I'm interested to see what someone with more experience (and probably using PI) can mange compared to what I'm ending up with. I've been generally happy with my results but I always wonder if more could be done with my current data and I just don't know how to do it. 

 

If anyone would be willing to do this, I would greatly appreciate the time and effort. My M42 is my favorite image and I think it provides a unique view of a commonly imaged target. Being my favorite, I would be interested in having that one done along with either M1 or one of my galaxy images. Check out my Astrobin account here to see the targets I've imaged so far: https://www.astrobin.../tjschultz2011/

 

I shoot with an unmodified Canon 6D attached to a Paracorr II CC and with no filters. I also use flats, darks, and bias frames for all my images. If anyone is interested please let me know and I could send over a TIF file. Here's the M42 image in question:

 

[joeytroy]

You should just post the TIF and let users take a crack at it. I am game I have been going through a handful images The Elf offered up.

 

https://www.cloudyni...ice-processing/

[tjschultz2011]

You should just post the TIF and let users take a crack at it. I am game I have been going through a handful images The Elf offered up.

 

https://www.cloudyni...ice-processing/

What's the best way to post access to a tif file on here? Looks like the tif file for the above image is 213 mb

[joeytroy]

Most users post it on google drive, or dropbox with a link.

[tjschultz2011]

https://drive.google...iew?usp=sharing

 

Ok, I think I did this correctly. Let me know if the drive link doesn't work. This is the M42 image above

[joeytroy]

You need to change it to all users can read for the permissions here is an example of one of my files.

 

 

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[tjschultz2011]

Ok, got it. Thanks for the help with that. Here are some links to M42 and other TIF files for anyone to work on that wants to. Feel free to post your results on here and to ask any questions you may have about my equipment, methods, or integration details for any of the images. Also feel free to ask for TIF files of my other targets on Astrobin if you'd like. 

 

 

M42: https://drive.google...iew?usp=sharing

 

M1: https://drive.google...iew?usp=sharing

 

M81: https://drive.google...iew?usp=sharing

 

M101: https://drive.google...iew?usp=sharing

 

M51: https://drive.google...iew?usp=sharing

 

M33: https://drive.google...iew?usp=sharing

Edited by tjschultz2011, 21 January 2021 - 02:48 PM.

[Tapio]

Here's my not so dramatic vision.

 

You had amp glow in the right bottom&top.

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Edited by Tapio, 21 January 2021 - 01:56 PM.

[tjschultz2011]

Yeah, I get that on the corners of my images because my scopes image circle doesn't fill my full frame sensor and/or the Paracorr II is designed for crop sized sensors. It looks like amp glow but I think it's just bad vignetting that usually shows up as pinkish when stretched even using flat frames. I can sometimes make a synthetic flat frame in Photoshop and subtract it from the image to mitigate this but it's difficult when the target fills the whole frame like M42 does. 

[Tapio]

If you have dark frame optimization checked you might want to try without.

 

https://www.cloudyni...dont-help-much/

[slepage]

To me it looks pretty good.  I took about 5 mins to change a few things such as I got rid of what looks like a greenish cast and tried to pull out a bit more color depth and also a bit more of the faint areas.  I did not do a complete re-due.  What do you think?  Yours on top, mine on bottom.

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Edited by slepage, 21 January 2021 - 02:32 PM.

[rkinnett]

Here's my take

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[tjschultz2011]

Thanks guys, looks good! I love seeing different people's artistic take on the same data. Ryan, you were really able to pull out a lot of the faint wispy details around the edges 

[tjschultz2011]

Here's my original attempt at the M42 image. It had slightly less saturation on the colors and was stretched a little more to show some more details. Which do you guys prefer? This one or the one I settled on and posted at the top? 

 

[joeytroy]

That was fun, stings about the amp glow as I love the large star that needed to get cut out. Still lots of great detail regardless.

 

[tjschultz2011]

That was fun, stings about the amp glow as I love the large star that needed to get cut out. Still lots of great detail regardless.

 

Wow, love the colors you got out of there

[joeytroy]

M1

 

[Ron (Lubbock)]

Here's my result on M42 using GIMP and several other programs.  I could probably do better with the slightly colored halo around the nebula, but I managed to fudge out the amp glow well enough to keep the bright star.

 

Edited by Ron (Lubbock), 21 January 2021 - 04:26 PM.

[rkinnett]

By the way, the light corners in the raw M42 stack are probably not due to amp glow.. they're present in all four corners, in a roughly symmetric radial pattern.  Looks to me like DSS may be overcorrecting vignetting with flat frame calibration.  What do your master dark and flat frames look like (stretched)?

 

The image is quite nice to work with, otherwise.  Nice job.

[tjschultz2011]

Here's my result on M42 using GIMP and several other programs.  I could probably do better with the slightly colored halo around the nebula, but I managed to fudge out the amp glow well enough to keep the bright star.

 

Wow! Really like what you did with it. The colors are subtle and natural looking and a lot more of the dust is visible around the far edges. Thanks for sharing

[tjschultz2011]

By the way, the light corners in the raw M42 stack are probably not due to amp glow.. they're present in all four corners, in a roughly symmetric radial pattern.  Looks to me like DSS may be overcorrecting vignetting with flat frame calibration.  What do your master dark and flat frames look like (stretched)?

 

The image is quite nice to work with, otherwise.  Nice job.

Thanks Ryan. I'm still amazed by what the scope can do in a short amount of time. That M42 image is only 5 minutes worth of 10 second exposures. 

 

I don't think I have the master dark or flat frames saved anywhere and our windows computer is down right now so I can't restack the subs. But I do have the individual frames of each so I'll post them here. This is a single flat frame (unstretched). To take them I put the scopes large white astrosystems cover over the end as tight as I can make it and point the scope low at the eastern horizon right before sunset. 

 

[tjschultz2011]

And this is a single dark frame stretched a lot. I do see something in the bottom right corner but the other corners don't show it 

 

[Slice1969]

Here is my crack at it:

 

[Ron (Lubbock)]

By the way, the light corners in the raw M42 stack are probably not due to amp glow.. they're present in all four corners, in a roughly symmetric radial pattern.  Looks to me like DSS may be overcorrecting vignetting with flat frame calibration.  What do your master dark and flat frames look like (stretched)?

 

The image is quite nice to work with, otherwise.  Nice job.

I agree that it's a problem with flats. I don't know why I repeated the "amp glow" suggestion.  If only we lived in a world where all flats were perfect...

Edited by Ron (Lubbock), 21 January 2021 - 07:37 PM.

[rkinnett]

Flats for sure

 

There should be some threads around here about tuning the flat calibration parameters.  I had the same problem last week and haven't had time to really dig into it yet.