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Seanelly

Help analyze M81-M82 1x180s vs 37x180s

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Only my third imaging subject, and I'm wondering why I'm not seeing more results from the quantity of data collected.

The (1) single raw 3-minute unprocessed frame shows a noticeable amount more colour and detail than the (2) 37 raw 3-minute unprocessed images stacked with ten each of darks, flats and bias in DeepSkyStacker. Certainly the long exposure image is much cleaner, and in processing with a generic photo editor (I've yet to realize Adobe PhotoshopCC) I can produce a passable image as seen in the (3) third photo, but with reduced red colour in M82 than even the single 3-minute image.

Is there a problem here? Suggestions? 

(All images at 800iso, using modified Canon T6i (750D) DSLR with IDAS LPS D1 clip-in, and APO refractor and mount, etc., listed in signature)

 

(1) 1x180s

1900380145_M81-M82singleframe.thumb.jpg.7dcd6f86e48d59b62959a78bc4072457.jpg

 

(2) 37x180s stacked, 10 each dark, flat, bias

2017854841_WTFM81-M82.thumb.jpg.1f1e0ee553ef1191ecca404f69d513fd.jpg

 

(3) 37x180s, 10 each dark, flat, bias

218896029_M81-M824thJPEG.thumb.jpg.d8b891cc950c1d1752c33d15fc693c97.jpg

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7 minutes ago, Seanelly said:

Only my third imaging subject, and I'm wondering why I'm not seeing more results from the quantity of data collected.

The (1) single raw 3-minute unprocessed frame shows a noticeable amount more colour and detail than the (2) 37 raw 3-minute unprocessed images stacked with ten each of darks, flats and bias in DeepSkyStacker. Certainly the long exposure image is much cleaner, and in processing with a generic photo editor (I've yet to realize Adobe PhotoshopCC) I can produce a passable image as seen in the (3) third photo, but with reduced red colour in M82 than even the single 3-minute image.

Is there a problem here? Suggestions? 

(All images at 800iso, using modified Canon T6i (750D) DSLR with IDAS LPS D1 clip-in, and APO refractor and mount, etc., listed in signature)

 

(1) 1x180s

1900380145_M81-M82singleframe.thumb.jpg.7dcd6f86e48d59b62959a78bc4072457.jpg

 

(2) 37x180s stacked, 10 each dark, flat, bias

2017854841_WTFM81-M82.thumb.jpg.1f1e0ee553ef1191ecca404f69d513fd.jpg

 

(3) 37x180s, 10 each dark, flat, bias

218896029_M81-M824thJPEG.thumb.jpg.d8b891cc950c1d1752c33d15fc693c97.jpg

One suggestion I would make would be to try another stacking program. Free trial of Astro Pixel Processor would be my recommendation. I had the same issue with DSS where there was literally very little colour in the stacks. There may be settings to adjust, I tried many different ways, all ended washed out. APP is a step ahead of DSS 

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DSS does tend to generate pale images but this can be corrected in post processing, there is I believe a new version of DSS out but I haven't tried it.

You can mask out the galaxies and work on them separate to the background.

Dave

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30 minutes ago, tooth_dr said:

One suggestion I would make would be to try another stacking program. Free trial of Astro Pixel Processor would be my recommendation. I had the same issue with DSS where there was literally very little colour in the stacks. There may be settings to adjust, I tried many different ways, all ended washed out. APP is a step ahead of DSS 

Thanks for the response.

I might perhaps try their 30-day trial offer to compare the two apps. The problem I'd have with going the permanent APP route would be cost, as this kit has used up all my allowances for the next ten years or so, haha, and I still have to consider the cost of PhotoshopCC membership and also I need to purchase a second LPS filter that will accomodate my DSLR 58mm EF-S lenses for wide-field imaging-either the LPS lens filter or buy two more lenses, the EF variety, at huge cost, because my two EF-S lenses will not accomodate the DSLR IDAS LPS D1 clip-in filter (they simply bottom out against the filter before reaching their lockpoint), something I didn't know about to begin with. $$$$$!!!!! oh, my.

That said, I want the best images I can produce, and if APP proves better, I will in the end use it, and appreciate the suggestion, but in the meantime, I'm stuck with DSS for the foreseeable future.

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GIMP does a good job if you can figure out how to use it :grin:

Dave

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9 minutes ago, Davey-T said:

DSS does tend to generate pale images but this can be corrected in post processing, there is I believe a new version of DSS out but I haven't tried it.

You can mask out the galaxies and work on them separate to the background.

Dave

Thanks for responding.

I download DSS in November; I will have to check on the version. I know that without dedicated processing software I am losing a lot of bang for my (non)buck, and I will have to simply bear the cost of Photoshop in the near future. Do you know of any better astrophoto freeware that I might use in the meantime that would give me better results than the generic microsoft photo editor?

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4 minutes ago, Davey-T said:

GIMP does a good job if you can figure out how to use it :grin:

Dave

Ha ha, just asked you if you could recommend any better freeware than the generic microsoft editor I have. Are you serious about GIMP?

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I agree with tooth-dr.   Your first image above is similar to what I occasionally see in CCDStack.  However, it is very easy to  correct it in CCDStack with a tweak of a slider. 

You can also easily fix it in any decent imaging processing software.  Below is a very quick tweak to your image done in Picture Window Pro (which is availablee free).  This is a great package to learn about image processing.  It is much easier to learn than Photoshop.  I would also recommend the Gimp, as it seems to be able to do everything that PS can do.

You have captured a great deal of detail in the "Cigar", so you should be very pleased with that result.

Here is the result of a simple levels adjustment to your top image.

 

Seanelly.jpg

Edited by don4l
Old and forgetful!

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Just now, Seanelly said:

Ha ha, just asked you if you could recommend any better freeware than the generic microsoft editor I have. Are you serious about GIMP?

I did have a play with it a couple of years ago and found it a bit clunky but it has been developed quite a bit since then and is said to do a pretty good impersonation of P'Shop in it's latest incarnation.

Dave

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3 minutes ago, don4l said:

I agree with tooth-dr.   Your first image above is similar to what I occasionally see in CCDStack.  However, it is very easy to  correct it in CCDStack with a tweak of a slider. 

You can also easily fix it in any decent imaging processing software.  Below is a very quick tweak to your image done in Picture Window Pro (which is availablee free).  This is a great package to learn about image processing.  It is much easier to learn than Photoshop.  I would also recommend the Gimp, as it seems to be able to do everything that PS can do.

You have captured a great deal of detail in the "Cigar", so you should be very pleased with that result.

Here is the result of a simple levels adjustment to your top image.

 

Thanks for the response. The first two images were left unprocessed so comparison could be made between them. I think you forgot to add the processed image in your post.

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4 minutes ago, Seanelly said:

Thanks for the response. The first two images were left unprocessed so comparison could be made between them. I think you forgot to add the processed image in your post.

Sorry about that.  I've added it now.

 

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Hi

It may be that light pollution is the root of your problems - I have the same curse. It's reducing your snr and you need many more subs at an optimised exposure length and iso (usually 800 for unity gain but can vary a bit). You also need many more calibration frames anyway. I generally think in terms of around 30 but maybe even more would be better. Some people don't use darks with dslrs.
I've always found Samir Kharusi's article helpful and informative. His comparison in number of subs required between a dark site and a suburban site is a depressing revelation (eg only 64min vs 16 hours under lp).

Louise

Edited by Thalestris24

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2 hours ago, Thalestris24 said:

Hi

It may be that light pollution is the root of your problems - I have the same curse. It's reducing your snr and you need many more subs at an optimised exposure length and iso (usually 800 for unity gain but can vary a bit). You also need many more calibration frames anyway. I generally think in terms of around 30 but maybe even more would be better. Some people don't use darks with dslrs.
I've always found Samir Kharusi's article helpful and informative. His comparison in number of subs required between a dark site and a suburban site is a depressing revelation (eg only 64min vs 16 hours under lp).

Louise

Thanks for taking time to respond.

I'm living in Bortle 7 skies just outside the city (Ottawa), with no streetlamps, and city glow to the north and west, which would interfere somewhat with M-81 and M82 imaging, but overall pretty decent dark skies, using an IDAS LPS D1 clip-in, and in this case at 800iso. I read the article, which leans toward helping those taking short exposure images because of less than exemplary tracking mounts without autoguiding, but it was nevertheless helpful. I was not aware that so many calibration frames were necessary (the thought crossed my mind that I was adding too many, which was contributing to dulling the final image. Hey, I'm new to this!), and I will have to experiment further with increasing these, but the number of subs will definitely have to be increased in this case to draw out more detail. My original concern was that compared to the single 180s image shown, the 37 180s light frames stacked in DeepSkyStacker (with ten each of darks, lights and bias) seemed to show poorly in the finished product before processing. I don't mind spending the time getting the images, I just want to be sure I'm wasting as little time as possible because clear skies are as rare here in Ottawa these days as they seem to be over the British Isles, which is a surprise to me. Thanks again.

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4 hours ago, Seanelly said:

Are you serious about GIMP?

I'm just starting to get to grips with this program and, combined with Sharpcap's live stacking option, I am quite hopeful about the results I am starting to get. It used to be a bit of a joke because it only worked in 8 bits, but 2.10 works in 16 and it is a lot better. Most AP instruction manuals out there tend to focus on PS and I am a bit of a clutz when it comes to translating specific instructions for one program into the equivalent instructions in another, but I'm getting there. Most importantly, from my point of view, is the cost!

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An alternative to Gimp and PS CC is Affinity Photo. Much more user friendly than gimp and a lot cheaper than PS CC. Well supported and lots of YouTube videos on how to use it. 

Paint ShoP Pro is another good option but Affinity have killed it with the new version 2 release. 

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31 minutes ago, Demonperformer said:

I'm just starting to get to grips with this program and, combined with Sharpcap's live stacking option, I am quite hopeful about the results I am starting to get. It used to be a bit of a joke because it only worked in 8 bits, but 2.10 works in 16 and it is a lot better. Most AP instruction manuals out there tend to focus on PS and I am a bit of a clutz when it comes to translating specific instructions for one program into the equivalent instructions in another, but I'm getting there. Most importantly, from my point of view, is the cost!

Thanks for responding.

I tried to download this program and got this negative message: This program can only be installed on versions of windows designed for the following processor architectures: x64.

I have window 10. Any idea what that message means, 'cause I sure don't.

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5 minutes ago, Seanelly said:

Thanks for responding.

I tried to download this program and got this negative message: This program can only be installed on versions of windows designed for the following processor architectures: x64.

I have window 10. Any idea what that message means, 'cause I sure don't.

How old is your computer and or are you only running the 32bit version of W10?

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I think APP would be a better investment than a second light Polution filter. If you want a good image you are going to want a software package than can help you remove lightpolution and calibrate the background. I am currently trialing APP and it is very impressive, with standard settings it will get you massively improved images, even if PixInsight is still a little better at removing lp. APP is very easy to use, and worth the cost.

My personal experience is that your processing skills and software will yield a bigger increase in quality than any gear you can buy (generally speaking). 🙂

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22 minutes ago, dannybgoode said:

How old is your computer and or are you only running the 32bit version of W10?

Just checked: 32-bit operating system, x64 based processor. Does this (x64 based processor) mean I can upgrade to the 64-bit op sys?

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9 minutes ago, jjosefsen said:

I think APP would be a better investment than a second light Polution filter. If you want a good image you are going to want a software package than can help you remove lightpolution and calibrate the background. I am currently trialing APP and it is very impressive, with standard settings it will get you massively improved images, even if PixInsight is still a little better at removing lp. APP is very easy to use, and worth the cost.

My personal experience is that your processing skills and software will yield a bigger increase in quality than any gear you can buy (generally speaking). 🙂

Very informative, thank you very much!

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15 minutes ago, jjosefsen said:

I think APP would be a better investment than a second light Polution filter. If you want a good image you are going to want a software package than can help you remove lightpolution and calibrate the background. I am currently trialing APP and it is very impressive, with standard settings it will get you massively improved images, even if PixInsight is still a little better at removing lp. APP is very easy to use, and worth the cost.

My personal experience is that your processing skills and software will yield a bigger increase in quality than any gear you can buy (generally speaking). 🙂

Sorry, just googled APP and can't find what the acronym stands for, if you could flesh out the words?

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40 minutes ago, Seanelly said:

Just checked: 32-bit operating system, x64 based processor. Does this (x64 based processor) mean I can upgrade to the 64-bit op sys?

Yes you can. It may not even cost you anything. 

APP stands for Astro Pixel Processor. Another option is Nebulosity 4 and this acts as a camera control program as well as a stacker and image processor. 

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There is a ton to do software out there, thankfully some of them have trials.

The reason I'm pushing APP is because it does a really good job without too much user input.ø, so I think for a beginner it is a massive step up compared to DSS, and much simpler than PixInsight.

I have and use mostly PixInsight, but I think I'm going to end up buying Astro Pixel Processor (APP).

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Going from 32-bit Windows 10 to 64-bit requires a clean install. It's probably only worth doing if you have a decent spec computer or are willing to upgrade the hardware. Otherwise it may be better to simply by a new one.

Louise

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