Is this what light polution looks like?

[George Gearless]

Hey guys.

I've recently purchased a new camera. And a couple of days ago I had the fortune to give it a whirl on, amongst others, Andromeda.

But I'm getting very light background. Almost to the point of being gray. There's only so much I can do about it in StarTools. I can stretch it beond recognition so I get a fairly decent black/dark background. But then Andromeda looks like an Andy Warhole painting with vicious colours of magenta, yellow and red.

But before I go out and buy myself a filter to combat the artificial lights in my suburban neighbourhood, I'd like to confirm that this is indeed ligth polution. The picture below is from Startools autodevelop mode and added scientific colours so as not to make it too offensive to look at. But other than that, it has not been pulled through the wringer. Yes, I know. It's wrong side up, not sharpened, not contrasted, not anything. My purpose here is simply to establish if an artificial lightfilter would help the situation here.

Addendum: If it is indeed light polution that's causing this, would you have any recommendations? Filter wise, I mean.

 

George.

 

[Macavity]

To some extent, I gave up wondering, and invested in a Baader Neodymium
filter THEN a Baader UHC Filter. lol. The latter removes almost everything re.
light pollution in more "Stellar" & HA/OIII objects! The main question locally
concerns replacement of White LED street lighting over old "orange" ones? 🤔
(Most of my light pollution "tests" with a DSLR were perfomed before this!)

As a general (more hopeful) thought here:

Despite it's obvious attactions, M31 is a *relatively difficult* object to separate
WELL from the background. It tends toward being the same (yellowish) colour
as light pollution? The (promising) brightness of nearby galaxies is distributed
over a large area. The surface brightness of M31's outer regions is only (ISTR!)
Magnitude +17 to +20! That is getting close to (many) "sky backgrounds"... 😐

Buy a Baader LHC (a personal prejudice!) for nebulae etc.  It will not work well
with Galaxies, unless you want to image HA rich regions of M31? If you do want
to image Galaxies, more compact (distant!) ones can image surprisingly well
despite the light pollution. A "lighter-weight" Neodymium etc., may help? 😉

Edited October 16, 2021 by Macavity

[The Lazy Astronomer]

1 hour ago, George Gearless said:

Hey guys.

I've recently purchased a new camera. And a couple of days ago I had the fortune to give it a whirl on, amongst others, Andromeda.

But I'm getting very light background. Almost to the point of being gray. There's only so much I can do about it in StarTools. I can stretch it beond recognition so I get a fairly decent black/dark background. But then Andromeda looks like an Andy Warhole painting with vicious colours of magenta, yellow and red.

But before I go out and buy myself a filter to combat the artificial lights in my suburban neighbourhood, I'd like to confirm that this is indeed ligth polution. The picture below is from Startools autodevelop mode and added scientific colours so as not to make it too offensive to look at. But other than that, it has not been pulled through the wringer. Yes, I know. It's wrong side up, not sharpened, not contrasted, not anything. My purpose here is simply to establish if an artificial lightfilter would help the situation here.

Addendum: If it is indeed light polution that's causing this, would you have any recommendations? Filter wise, I mean.

 

George.

 

Did you run it through the wipe module first?

There's no real way to completely escape light pollution during capture (except maybe going to out into the middle of nowhere!) but wipe, or other similar background extraction routines in other software, should help to remove/reduce the effects of it.

Another thing to consider is your exposure length. What's the setup you used here and where on the bortle scale are you?

[George Gearless]

1 hour ago, Macavity said:

To some extent, I gave up wondering, and invested in a Baader Neodymium
filter THEN a Baader UHC Filter. lol. The latter removes almost everything re.
light pollution in more "Stellar" & HA/OIII objects! The main question locally
concerns replacement of White LED street lighting over old "orange" ones? 🤔
(Most of my light pollution "tests" with a DSLR were perfomed before this!)

As a general (more hopeful) thought here:

Despite it's obvious attactions, M31 is a *relatively difficult* object to separate
WELL from the background. It tends toward being the same (yellowish) colour
as light pollution? The (promising) brightness of nearby galaxies is distributed
over a large area. The surface brightness of M31's outer regions is only (ISTR!)
Magnitude +17 to +20! That is getting close to (many) "sky backgrounds"... 😐

Buy a Baader LHC (a personal prejudice!) for nebulae etc.  It will not work well
with Galaxies, unless you want to image HA rich regions of M31? If you do want
to image Galaxies, more compact (distant!) ones can image surprisingly well
despite the light pollution. A "lighter-weight" Neodymium etc., may help? 😉

I was probably going to get a filter eventualy anyway. 

The example I posted here was just one I had readily available for uploading. I'm not partial to any DSO types as such.

So thankyou for your advice.

George

[Lee_P]

The thing about broadband light pollution filters is that their level of effectiveness is very much related to your local sky conditions and the kit that you're using. Recommendations from other people are only of limited use -- what works for one person might not work for you, and vice versa. I tested a few light pollution filters and found that for me they either made negligible difference, or actually did more harm than good. More info here. Really, you need to get some and try them for yourself. I'm in Bortle 8 skies and for broadband targets don't actually use a filter at all, instead using long integration times to combat light pollution and get a decent signal-to-noise ratio.

M31 was my latest imaging project too. For a reference point, here's a single sub:

 

And here's a 24-hour integration, no light pollution filter:

 

And here's the result after processing:

 

So, my advice is to get hold of a few light pollution filters if you can, and give them a test. You may find one that works for you; maybe not. In either case, long integration times are your best friend when it comes to combatting light pollution when imaging broadband targets. (Narrowband targets do definitely benefit from particular filters).

Edited October 16, 2021 by Lee_P
Included the 24-hour integration image for clarity.

[George Gearless]

19 minutes ago, The Lazy Astronomer said:

Did you run it through the wipe module first?

There's no real way to completely escape light pollution during capture (except maybe going to out into the middle of nowhere!) but wipe, or other similar background extraction routines in other software, should help to remove/reduce the effects of it.

Another thing to consider is your exposure length. What's the setup you used here and where on the bortle scale are you?

The wipe module in Startools wreaks absolute havoc on my pictures. I have tried the different presettings. All of them completely messes up the picture and creates strange geometrical lightshapes over the picture.

I'll admit, I have probably not investigated the manual tweaking enough. This is mainly due to my lack of knowledge of the program. I've only ever used the 'quick fix' preloaded options of the program. I'll look more into it after your post.

I'm not sure where on the bortle scale I'm at. But there is an annoying street lamp very close to my backyard where I set up (it's a white light). If at all possible (as it was in this case) I try to avoid pointing the telescope in that direction. If I were to guess, I'm probably around 6 or 5 on the Bortle scale.

Some setup and picture info (for this picture):

25 x 2 min exposure lights, 15 darks

Gain 500

Binning 1x1

Camera, Omegon Vetec 533 C (cooled to -10)

Skywatcher ED80

Guided

Stacked in DSS

I use Stellarmate/Ekos for all my photographing sessions.

 

 

[George Gearless]

3 minutes ago, Lee_P said:

The thing about broadband light pollution filters is that their level of effectiveness is very much related to your local sky conditions and the kit that you're using. Recommendations from other people are only of limited use -- what works for one person might not work for you, and vice versa. I tested a few light pollution filters and found that for me they either made negligible difference, or actually did more harm than good. More info here. Really, you need to get some and try them for yourself. I'm in Bortle 8 skies and for broadband targets don't actually use a filter at all, instead using long integration times to combat light pollution and get a decent signal-to-noise ratio.

M31 was my latest imaging project too. For a reference point, here's a single sub:

 

And here's a 24-hour integration. No light pollution filter:

 

So, my advice is to get hold of a few light pollution filters if you can, and give them a test. You may find one that works for you; maybe not. In either case, long integration times are your best friend when it comes to combatting light pollution when imaging broadband targets. (Narrowband targets do definitely benefit from particular filters).

Thanks Lee. That was most helpful. 

Maybe I've just been too ambitious for my 25x2 min subs. 

 

[Lee_P]

7 minutes ago, George Gearless said:

I'm not sure where on the bortle scale I'm at. But there is an annoying street lamp very close to my backyard where I set up (it's a white light). If at all possible (as it was in this case) I try to avoid pointing the telescope in that direction. If I were to guess, I'm probably around 6 or 5 on the Bortle scale.

You can go to https://www.lightpollutionmap.info/ and click on your location. That'll give you an indication of your Bortle scale. It may not be completely accurate, but it'll probably be close.

[George Gearless]

1 minute ago, Lee_P said:

You can go to https://www.lightpollutionmap.info/ and click on your location. That'll give you an indication of your Bortle scale. It may not be completely accurate, but it'll probably be close.

Nice. I'm a 4 then.

Thanks again.

 

 

 

[The Lazy Astronomer]

43 minutes ago, George Gearless said:

The wipe module in Startools wreaks absolute havoc on my pictures. I have tried the different presettings. All of them completely messes up the picture and creates strange geometrical lightshapes over the picture.

I'll admit, I have probably not investigated the manual tweaking enough. This is mainly due to my lack of knowledge of the program. I've only ever used the 'quick fix' preloaded options of the program. I'll look more into it after your post.

I'm not sure where on the bortle scale I'm at. But there is an annoying street lamp very close to my backyard where I set up (it's a white light). If at all possible (as it was in this case) I try to avoid pointing the telescope in that direction. If I were to guess, I'm probably around 6 or 5 on the Bortle scale.

Some setup and picture info (for this picture):

25 x 2 min exposure lights, 15 darks

Gain 500

Binning 1x1

Camera, Omegon Vetec 533 C (cooled to -10)

Skywatcher ED80

Guided

Stacked in DSS

I use Stellarmate/Ekos for all my photographing sessions.

 

 

Ah, yes, wipe will do that if there are stacking artifacts around the edges or what startools refers to as "dark anomalies" in the image (e.g. dead pixels, or small dark dust shadows). From the image you've posted above, it doesn't look like there's any dust shadows, so l would suggest there's probably some stacking artifacts messing with wipe's algorithm (it really, really hates them!!). Try cropping the edges of the frame first.

Feel free to upload your stacked fits file and I'll have a play around with it if you want?

2 minute exposures are probably fine. It's probably longer than you need to do, but you won't be overexposing.

[George Gearless]

3 hours ago, The Lazy Astronomer said:

Ah, yes, wipe will do that if there are stacking artifacts around the edges or what startools refers to as "dark anomalies" in the image (e.g. dead pixels, or small dark dust shadows). From the image you've posted above, it doesn't look like there's any dust shadows, so l would suggest there's probably some stacking artifacts messing with wipe's algorithm (it really, really hates them!!). Try cropping the edges of the frame first.

Feel free to upload your stacked fits file and I'll have a play around with it if you want?

2 minute exposures are probably fine. It's probably longer than you need to do, but you won't be overexposing.

I'd be delighted for you to have a crack at it.

But please, don't feel obligated, if you somewhere in your process decide it'll take too much of your time. But I would love, if nothing else, to see if you can somehow get that smooth dark black background that I feel is missing above all else in this picture. That would indicate that the data is not flawed beond repair, but that my expertise in Startools is. The latter, is something I can adress. The former, something I can revisit the next time the weatherman allows me to go outside and play again.

 

Edit: As you'll no doubt discover, there's a giant dustbunny near the top right corner. Flats do diminish it substantialy but not entirely. Just looks like a big bulging watermark after processing. The attached .FTS has only lights and darks. Added a 16 bit TIF as well. Not sure what you're used to working with. 

AndromedaStacked.FTS

andromedastacked.TIF

Edited October 16, 2021 by George Gearless

[Lee_P]

I don't use StarTools, but had a crack at your image using PixInsight and Lightroom. Literally five minutes of work, so I was quite blunt in my editing. Just wanted to get an idea of what can be pulled out.

 

There's a fair amount of data in there, especially considering it's a short integration.

A few things to note:

* I think that your focus is slightly off. I'd expect it to all be a bit sharper. This might be a limitation of the telescope optics, but my first guess is focus.
* You've got some satellite trails in there. They should be removed during stacking, so maybe check your settings.
* The dust bunny was annoying! Normally that would be an easy fix -- remove all the stars using Starnet, then clone out the dust spot in the starless image -- but Starnet didn't work, I think because your image is slightly out of focus. So I just cloned it out. Not sure how you'd handle this in StarTools but I'm sure there will be a good way.
* Many of your stars have this strange pattern. Not sure what's causing it. Perhaps some kind of internal reflection? Others can diagnose better than I

 

Overall I'd say that your data acquisition was a good attempt, and I think you'll be producing some really good images in the near future!

[almcl]

I had a little play with your .fits file in StarTools and got the result below.  The colour does look a bit off, not sure if that's light pollution or something the stacking software has done?  And as Lee_P has said, the dust bunny did require a bit of work but there are some nice dust lanes and, with a slightly harder focus quite a bit of detail should be available.

If you want to bring the discussion over to the StarTools forum, others will doubtless be able to give more, better qualified opinions.

 

[George Gearless]

9 hours ago, Lee_P said:

I don't use StarTools, but had a crack at your image using PixInsight and Lightroom. Literally five minutes of work, so I was quite blunt in my editing. Just wanted to get an idea of what can be pulled out.

 

There's a fair amount of data in there, especially considering it's a short integration.

A few things to note:

* I think that your focus is slightly off. I'd expect it to all be a bit sharper. This might be a limitation of the telescope optics, but my first guess is focus.
* You've got some satellite trails in there. They should be removed during stacking, so maybe check your settings.
* The dust bunny was annoying! Normally that would be an easy fix -- remove all the stars using Starnet, then clone out the dust spot in the starless image -- but Starnet didn't work, I think because your image is slightly out of focus. So I just cloned it out. Not sure how you'd handle this in StarTools but I'm sure there will be a good way.
* Many of your stars have this strange pattern. Not sure what's causing it. Perhaps some kind of internal reflection? Others can diagnose better than I

 

Overall I'd say that your data acquisition was a good attempt, and I think you'll be producing some really good images in the near future!

 

I have gotten simillar results as yours with Startools, although I spent much longer time than you to achieve it. I am however content with your result because it confirms that I'm not doing something fundamentaly wrong in my processing in Startools. 

Although I cannot entirely discount that the image is slightly out of focus, I think it more likely that I've messed something up in settings of DSS. I use an EAF and feel confident that Ekos' focusing module has done its job . Thinking back, I did change some settings when I stacked my second target (IC405) and they don't seem to have the same saturn-like rings on them. I think it was the settings involving cleaning cold/hot pixels? Easily found out. I'll just do a restack and see whats what.

Here's IC405 from that same night, same focus, but 15x5min subs. Fiarly round stars I'd say. But I have a suspicion that I changed the hot/cold picxel repair in DSS for this stack:

 

 

As for the dustbunny and sattelite trail, those have obvious solutions that I was just to lazy to do anything about for the purpose of the 'dark background' issue I was struggling with. Remove the bunny physicallly, and identify and leave out the satelite pic in the next stack. And yes, I too can see the dark square box that seems to frame the center of this picture. No idea how that came about. But let's leave that for another thread :).

Thankyou so much for your helpful feedback. From this short thread I've learned more than I could study my way to in days. Also thankyou for taking the time to have a crack at it. Even if it was only for 5 mins.

 

George

 

 

[George Gearless]

9 hours ago, almcl said:

I had a little play with your .fits file in StarTools and got the result below.  The colour does look a bit off, not sure if that's light pollution or something the stacking software has done?  And as Lee_P has said, the dust bunny did require a bit of work but there are some nice dust lanes and, with a slightly harder focus quite a bit of detail should be available.

If you want to bring the discussion over to the StarTools forum, others will doubtless be able to give more, better qualified opinions.

 

Well, spank my bottom and call me Susan!

There it is. The dark canvas of space on which Andromeda is painted. 

This is very encouraging. Although I still have a lot to learn about AP, I have even more to learn about processing. It is admittedly one of my (many) shortcommings. What you have achieved by "a little play with" I could not achieve in days of frustration. It confirms with remarkable clarity what so many have said, that data is king in this 'business'. I can only imagine what can be achieved with longer integration. Weather permitting, I won't have to imagine much longer.

I was unaware that there was a ST forum. And for some reason I didn't think to search for one. I've only ever watched some how-to videos on Youtube. So thanks for pointing me in that direction. 

Thankyou ever so much for taking the time with this. I feel very encouraged by it!

George

 

[Lee_P]

5 hours ago, George Gearless said:

 

I have gotten simillar results as yours with Startools, although I spent much longer time than you to achieve it. I am however content with your result because it confirms that I'm not doing something fundamentaly wrong in my processing in Startools. 

Although I cannot entirely discount that the image is slightly out of focus, I think it more likely that I've messed something up in settings of DSS. I use an EAF and feel confident that Ekos' focusing module has done its job . Thinking back, I did change some settings when I stacked my second target (IC405) and they don't seem to have the same saturn-like rings on them. I think it was the settings involving cleaning cold/hot pixels? Easily found out. I'll just do a restack and see whats what.

Here's IC405 from that same night, same focus, but 15x5min subs. Fiarly round stars I'd say. But I have a suspicion that I changed the hot/cold picxel repair in DSS for this stack:

 

 

As for the dustbunny and sattelite trail, those have obvious solutions that I was just to lazy to do anything about for the purpose of the 'dark background' issue I was struggling with. Remove the bunny physicallly, and identify and leave out the satelite pic in the next stack. And yes, I too can see the dark square box that seems to frame the center of this picture. No idea how that came about. But let's leave that for another thread :).

Thankyou so much for your helpful feedback. From this short thread I've learned more than I could study my way to in days. Also thankyou for taking the time to have a crack at it. Even if it was only for 5 mins.

 

George

 

 

That image looks out of focus to me as well. Maybe get some more opinions on that though? I'd expect an EAF to nail it.

Satellite trails should be automatically removed if you use a particular stacking algorithm -- I think it's Sigma Kappa, but I'm not 100% on that. That would mean you could keep individual images with satellite trails in your stack.

[The Lazy Astronomer]

9 hours ago, George Gearless said:

 

I have gotten simillar results as yours with Startools, although I spent much longer time than you to achieve it. I am however content with your result because it confirms that I'm not doing something fundamentaly wrong in my processing in Startools. 

Although I cannot entirely discount that the image is slightly out of focus, I think it more likely that I've messed something up in settings of DSS. I use an EAF and feel confident that Ekos' focusing module has done its job . Thinking back, I did change some settings when I stacked my second target (IC405) and they don't seem to have the same saturn-like rings on them. I think it was the settings involving cleaning cold/hot pixels? Easily found out. I'll just do a restack and see whats what.

Here's IC405 from that same night, same focus, but 15x5min subs. Fiarly round stars I'd say. But I have a suspicion that I changed the hot/cold picxel repair in DSS for this stack:

 

 

As for the dustbunny and sattelite trail, those have obvious solutions that I was just to lazy to do anything about for the purpose of the 'dark background' issue I was struggling with. Remove the bunny physicallly, and identify and leave out the satelite pic in the next stack. And yes, I too can see the dark square box that seems to frame the center of this picture. No idea how that came about. But let's leave that for another thread :).

Thankyou so much for your helpful feedback. From this short thread I've learned more than I could study my way to in days. Also thankyou for taking the time to have a crack at it. Even if it was only for 5 mins.

 

George

 

 

As others have already done this, it's probably not so relevant now, but this was the product of 5 or 10 minutes in startools. Nothing fancy done, just a basic crop, wipe, autodev, contrast, hdr (reveal core), colour and superstructure (isolate). I then went and added a bit of skyglow back in film dev:

 

I would have to agree with the others and say it looks like focus was slightly off and I would also say the focus looks slightly off in your IC405 image as well (although you have captured that lovely blue reflection nebula around AE Aurigae, which is very nice 🙂).

Below is the luminance channel from my recent attempt at M31, which I've rotated, cropped and resized to roughly match yours (all I've done to it is wipe and autodev) which I hope shows the difference, particularly on the smaller stars. 

 

As an end note, you may also have some chromatic aberration - this can be remedied with a UV/IR cut filter which cuts off the extremes of the blue and red light wavelengths (e.g. Astronomik L3)

[George Gearless]

11 hours ago, The Lazy Astronomer said:

As others have already done this, it's probably not so relevant now, but this was the product of 5 or 10 minutes in startools. Nothing fancy done, just a basic crop, wipe, autodev, contrast, hdr (reveal core), colour and superstructure (isolate). I then went and added a bit of skyglow back in film dev:

 

I would have to agree with the others and say it looks like focus was slightly off and I would also say the focus looks slightly off in your IC405 image as well (although you have captured that lovely blue reflection nebula around AE Aurigae, which is very nice 🙂).

Below is the luminance channel from my recent attempt at M31, which I've rotated, cropped and resized to roughly match yours (all I've done to it is wipe and autodev) which I hope shows the difference, particularly on the smaller stars. 

 

As an end note, you may also have some chromatic aberration - this can be remedied with a UV/IR cut filter which cuts off the extremes of the blue and red light wavelengths (e.g. Astronomik L3)

You have very much achieved what prompted me to ask in the first place. Namely to get a darker background.

I suspect the key to this is the 'wipe' function in Startools. A function that completely obliterates my pictures with strange lighting shapes. And by 'obliterates' I mean that you can hardly make out what the picture is supposed to be. I'll see if I can post a picture of it, so you can see what I mean. I am wondering why I am having this issue, when you are clearly not. A question probably more suited for an actual Startools forum.

As Lee suggested above, I've tried fiddling around with my stacking settings. Specifically Kappa Sigma clipping. And it did indeed remove the satellite trail precisely as he predicted. But on top of that, I've found the stars to be, not only a bit tighter, but remarkably so. I'm at work at the moment, but will post a new picture when I get back home tonight. 

Thankyou very much for taking the time to work a bit with the picture. And also for your advice that is helping me pinpoint, at least some of, the problems.

 

[The Lazy Astronomer]

2 hours ago, George Gearless said:

You have very much achieved what prompted me to ask in the first place. Namely to get a darker background.

I suspect the key to this is the 'wipe' function in Startools. A function that completely obliterates my pictures with strange lighting shapes. And by 'obliterates' I mean that you can hardly make out what the picture is supposed to be. I'll see if I can post a picture of it, so you can see what I mean. I am wondering why I am having this issue, when you are clearly not. A question probably more suited for an actual Startools forum.

As Lee suggested above, I've tried fiddling around with my stacking settings. Specifically Kappa Sigma clipping. And it did indeed remove the satellite trail precisely as he predicted. But on top of that, I've found the stars to be, not only a bit tighter, but remarkably so. I'm at work at the moment, but will post a new picture when I get back home tonight. 

Thankyou very much for taking the time to work a bit with the picture. And also for your advice that is helping me pinpoint, at least some of, the problems.

 

Just fyi, l cropped 3 pixels from each edge and masked off the dust bunny; wipe then seemed pretty happy to do its thing.

[George Gearless]

9 hours ago, The Lazy Astronomer said:

Just fyi, l cropped 3 pixels from each edge and masked off the dust bunny; wipe then seemed pretty happy to do its thing.

Ok, so I've checked up on the recommended stacking settings for ST and tried to do a re-run. Pretty big difference, I have to say. How to attain the pitch black bacground of space, still eludes me. I did try and crop, vigerously, to try and get the wipe function to work, and you were absolutely correct. Once I cropped out a significant amount of the picture, the wipe function did not mess things up as bad as previously. But still, I haven't quite gotten the hang of the function and need to work more on it. I'm convinced that this is key to getting the proper light. Incidently, I gave the glas plate in front of the camera a quick dust-off with a photography equipment brush, and it's all gone now. Was starting to bug the heck out of me.

I'm perfectly aware that I still have a long way to go. But because of the help I've recieved here, the journey doesn't seem so long and daunting as it might otherwise have. So thankyou to everyone for the help and very helpful advice. 

While I don't consider this picture the 'final, end all, be all' result because there's still so much to learn, I'm sure you'd agree that a prettier picture of the Andromeda galaxy has never been taken  .

 

 

[The Lazy Astronomer]

18 minutes ago, George Gearless said:

Ok, so I've checked up on the recommended stacking settings for ST and tried to do a re-run. Pretty big difference, I have to say. How to attain the pitch black bacground of space, still eludes me. I did try and crop, vigerously, to try and get the wipe function to work, and you were absolutely correct. Once I cropped out a significant amount of the picture, the wipe function did not mess things up as bad as previously. But still, I haven't quite gotten the hang of the function and need to work more on it. I'm convinced that this is key to getting the proper light. Incidently, I gave the glas plate in front of the camera a quick dust-off with a photography equipment brush, and it's all gone now. Was starting to bug the heck out of me.

I'm perfectly aware that I still have a long way to go. But because of the help I've recieved here, the journey doesn't seem so long and daunting as it might otherwise have. So thankyou to everyone for the help and very helpful advice. 

While I don't consider this picture the 'final, end all, be all' result because there's still so much to learn, I'm sure you'd agree that a prettier picture of the Andromeda galaxy has never been taken  .

 

 

Looking good 👍 

I would say though, don't worry too much about getting a dark black background - in fact, it's often commented on that startools processed images have too dark a background. Many people prefer a neutral dark grey background. I'm of the opinion that, as long as it isn't black clipped, the darkness of the background is to taste.

If you haven't already, check out the unofficial startools manual (available to download as a pdf from the startools website) - loads of useful info and tips and tricks in there.

[Lee_P]

30 minutes ago, George Gearless said:

Ok, so I've checked up on the recommended stacking settings for ST and tried to do a re-run. Pretty big difference, I have to say. How to attain the pitch black bacground of space, still eludes me. I did try and crop, vigerously, to try and get the wipe function to work, and you were absolutely correct. Once I cropped out a significant amount of the picture, the wipe function did not mess things up as bad as previously. But still, I haven't quite gotten the hang of the function and need to work more on it. I'm convinced that this is key to getting the proper light. Incidently, I gave the glas plate in front of the camera a quick dust-off with a photography equipment brush, and it's all gone now. Was starting to bug the heck out of me.

I'm perfectly aware that I still have a long way to go. But because of the help I've recieved here, the journey doesn't seem so long and daunting as it might otherwise have. So thankyou to everyone for the help and very helpful advice. 

While I don't consider this picture the 'final, end all, be all' result because there's still so much to learn, I'm sure you'd agree that a prettier picture of the Andromeda galaxy has never been taken  .

 

 

This is great! Fantastic progress. One more tip for the road: don't aim for pitch blackness. Space isn't actually completely black. It should be a little bit lighter. If you make your background black then you'll be missing detail.

[happy-kat]

StarTools protects against clipping data but does use the full dynamic range available and I find often pushes the peak left, but it wont have clipped the data. Though for personal taste in Filmdev I lift skyglow (leave the stretch as is)