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Help a Niall. Free Image file!


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Hi all

All this enforced free time seems to be creating a certain amount of stress and hand wringing. Having wasted  spent much of last night shooting the Auriga region and then subsequently trying to turn rags into riches yesterday evening and this morning I thought I would just give up and call in the big guns (i.e. people on here). I wont share what I have managed at this stage it is just too embarrassing. I am following this tutorial https://www.learnastronomyhq.com/articles/easy-dslr-astrophotography.html, and it seems to be going ok (except for the results!)

My attempt at editing this seems to have the following positive aspects:

  •  Round stars

And the following negative aspects:

  • Worrying lack of detail
  • Horrible vignetting
  •  Terrible amp glow
  • Crazy gradients
  • An almost depressing "few white dots on a black background" result / technicolour nightmare that looks nothing like an astronomy photo.

Now in my defence I did pick a relatively bland area of sky as I'm just trying to get the hang of basic focussing and tracking and subsequent editing. The focussing and tracking are ok it seems, and DSS seems happy enough, but the results at Gimp stage are consistently that appalling that I'm wondering if it is a) the camera or b) me (more likely the latter).

If anyone would feel like having a go at turning the attached TIF into an actual usable image that doesnt frighten pets and children I would consider it a massive personal favour. I'm just trying to narrow down why I am so wide of the mark when it comes to producing something worth looking at.

Lumix G2 (MFT) 14-42 kit lens at 42mm f5.6. ISO 400*. 32x90sec light 12x90 sec dark. Stacked in DSS

I know ISO 400 seems a bit low but at ISO 800 I get a white screen that is so white I ant actually pick out any individual stars.

Many many thanks all. Any advice really appreciated. I am happy to take any sort of criticism (astronomy related of course!).

platesolve result.png

dss output.TIF

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@Mr niall  Can we go back to basics.  Can you post a single sub straight from the camera - no processing of any kind. Then we can see if the banding is present on a single sub ie is the problem the ca

I had a quick go using Affinity Photo and came up with this result. It is showing vignetting and a strange line about 1/4 of the way down the image. I think that you need to increase the exposure but

I had a go using Photoshop (with Astronomy Tools actions) and Lightroom. There is definitely colour in there, but as PeterCPC said, there are a couple of horizontal  lines , one of which is green  . S

Posted Images

I had a quick go using Affinity Photo and came up with this result. It is showing vignetting and a strange line about 1/4 of the way down the image. I think that you need to increase the exposure but stars look round as you say.

Peter

dss output.jpg

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I had a go using Photoshop (with Astronomy Tools actions) and Lightroom. There is definitely colour in there, but as PeterCPC said, there are a couple of horizontal  lines , one of which is green  . Some vignetting too.

564067707_20200407-dssoutput.thumb.jpg.13bbbc7d1e816dd853bc61c69d35dd30.jpg

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If the image is stretched a lot, there is some vignetting.  Flats will help with this. 

Not sure about the banding with a Panasonic, (my DMC FZ30 isn't much use above ISO 200 but still managed some widefield shots) so maybe try dropping the ISO? 

You've got round, small stars; that's more than many of us manage with our first attempt, addressing any issues you dislike is now just a matter of time, research and trial and error.

Welcome to the dark side!

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Hi Niall,

I had a quick look see and I have to admit, I'm not seeing the problems you're talking about but do see two problems you didn't mention. You have a Cyan and a blue green line across your image that needs sorting as a priority.

There's no detail because I don't think you've taken a photo of anything. You have some vignetting but I've seen worse. Flats will help mitigate it but won't reduce the noise in the corners. I can't see much amp glow. I don't see any gradients worth worrying about.

What does perplex me is how you could go from an almost black image to a white image with just one stop ISO increase. Doesn't sound right to me :)

The lens you have looks to be pretty good.

If it was my image I'd be quite happy that I was on track other than the banding.

Dave.

 

dss output levels vig.jpg

Edited by davew
colour
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11 minutes ago, almcl said:

You've got round, small stars; that's more than many of us manage with our first attempt, addressing any issues you dislike is now just a matter of time, research and trial and error.

Welcome to the dark side!

Thanks that’s really useful! However I must admit this isn’t a first attempt, I’ve been doing this on and off for about 3 years. Seem to be fine with the “error” bit, it’s just the subsequent improvement that’s the issue!

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1 minute ago, david_taurus83 said:

The bands look like the outer edges of different frames. Did you move the camera a few times?

No camera didn’t move at all - it was on my last image too...

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3 hours ago, Mr niall said:

any sort of criticism

Hi

None really. Some nice star shapes and colours.

You could improve by taking flat frames and use a stacking method which includes the intersection of all frames.

HTH

1791247804_dssoutput.jpg.6216251c785cc677943400254e67a2f8.jpg

 

Edited by alacant
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1 hour ago, alacant said:

Hi

None really. Some nice star shapes and colours.

You could improve by taking flat frames and use a stacking method which includes the intersection of all frames.

HTH

1791247804_dssoutput.jpg.6216251c785cc677943400254e67a2f8.jpg

 

That is amazing! How on earth did you do that?

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Thanks for taking the time to look at this everyone. It is massively reassuring to know that I'm not going massively wrong. I feel like my underlying acquisition and editing maybe weren't too terrible its just that my expectations of what was realisable with the given data were much too optimistic. 

But with that in mind - where do you recommend I go from here? Apart from obviously picking a better target, the end result is still pretty... underwhelming. I would guess my editing workflow will need some development but I am struggling to find tutorials that I can readily transpose to Gimp. I have had a go at Startools but I just don't understand it. Within seconds I'm looking at a technicolor explosion of vomit.... 🙃

Here is my result below - I now see that I have stretched this much much too far to try and attempt to get data from it but looks like continuously stretching will only get me so far. And hopefully you can see what I thought was amp glow. And those dreaded lines of misery are even more evident.

 

forstar.jpeg

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2 hours ago, Mr niall said:

had a go at Startools but I just don't understand it

Sorry. Missed this bit. 

Which bit of it? The banding maybe? I'll try to help if I can.

Cheers

 

Edited by alacant
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34 minutes ago, alacant said:

Sorry. Missed this bit. 

Which bit of it? The banding maybe? I'll try to help if I can.

Cheers

 

Well I remember following a tutorial that said something like auto-dev then wiping various things like gradients and such. But  every time I ran anything it just created a crazy stretched mess with colours everywhere. Maybe I didn’t understand it. Do you know if there are any good tutorials out there - particularly for low quality noisy stuff like mine?

thanks again!

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19 minutes ago, Skipper Billy said:

Back ground extraction shows the true extent of the strange banding and the vignetting.

The banding is the first thing I would try to address - dodgy USB lead maybe ??

Thankyou - yes it is a bit of "70s wallpaper disaster" type effect. I don't have any USB's in the train though. Although I could try a different memory card maybe... 

Thanks for having a look really appreciate it.

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1 hour ago, alacant said:

Sorry. Missed this bit. 

Which bit of it? The banding maybe? I'll try to help if I can.

Cheers

 

Ok I was inspired so I had another go on star-tools and followed the tutorial on the star tools website; https://www.startools.org/modules/introduction/quick-start

I'm clearly experiencing a failure of intelligence here though because at the end of step 4 I did the second autodev as, I think, I was supposed to and ended up with the below pic. Now - I'm no Pete Lawrence, but I'm not sure that is quite correct... Especially  considering that step 5 is dedicated to "the teasing out of finer details".

hmmm...

 

star tools epic fail.PNG

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3 hours ago, Mr niall said:

ended up with the below pic

Hi

Yes, that's correct. That's what I got. That's just a big hammer stretch which frightens away most new users.  But you're not finished yet... The magic comes next...

In this case I think you forgot the 'banding' module before the wipe with 'vignetting' selected. Then call wipe again at around 90% with a mask to select only the band on the top part of the image. The milder bands will by now been removed as a result of the first call to banding. Finally call AutoDev a second time and adjust the 'ignore fine detail' slider with a roi over the fat star on the right of frame. Use the gamma slider to make it look realistic.

From there I used decon and colour before switching off database tracking and denoise. Then made it look nice in DarkTable. It sounds a lot but takes less than 5 minutes. Or significantly longer using other software... (...takes cover!)

HTH

 

Edited by alacant
gramática
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I think I have read before on here re banding and a Lumix camera. Might be worth a search.

Edit: I cannot find the post so I must have miss remembered.

Edited by happy-kat
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3 hours ago, alacant said:

Hi

Yes, that's correct. That's what I got. That's just a big hammer stretch which frightens away most new users.  But you're not finished yet... The magic comes next...

In this case I think you forgot the 'banding' module before the wipe with 'vignetting' selected. Then call wipe again at around 90% with a mask to select only the band on the top part of the image. The milder bands will by now been removed as a result of the first call to banding. Finally call AutoDev a second time and adjust the 'ignore fine detail' slider with a roi over the fat star on the right of frame. Use the gamma slider to make it look realistic.

From there I used decon and colour before switching off database tracking and denoise. Then made it look nice in DarkTable. It sounds a lot but takes less than 5 minutes. Or significantly longer using other software... (...takes cover!)

HTH

 

Nope still ended up with a crazy colour explosion! Or a hideously clipped black image with three white dots. Will have another go tomorrow! Many thanks

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10 minutes ago, Mr niall said:

crazy colour explosion!

That's strange.  Apart from the wipe preview, you should be working with luminance only until you force colour after initial development. Maybe you initially selected Linear rather than Linear OSC? Your roi for the second AutoDev should be restricted to a very small rectangle on the fat star only. It's something simple!

But as you say, tomorrow is another...

 

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Hi,

I would highly recommend doing as suggested in step 1 of the quick start tutorial, which is perusing the "starting with a good dataset" section.

Apologies in advance, as  I'm about to give some tough love....

Your dataset is not really usable in its current state. Anything you would learn trying to process it will likely not be very useful or replicable for the next dataset.

There are three important parts of astrophotography that need to work in unison. These three things are acquisition, pre-processing, and post-processing. Each step is dependent on the other in that sequence. Bad acquisition will lead to issues during pre-processing and post-processing.

You can try to learn these three things all at once, very slowly, or use a divide and conquer strategy.

If you want to learn post-processing now, try using a publicly available dataset. You will then know what an ok (not perfect) dataset looks like and how easy it really is to establish a quick, replicable workflow.

If you want to learn pre-processing, also try using a publicly available dataset (made up out of its constituent sub frames). You will then know what settings to use (per step 1 in the quick start tutorial, see here for DSS-specific settings) and what flats and bias frames do. Again, you will quickly settle on a quick, replicable workflow.

Finally, getting your acquisition down pat is a prerequisite for succeeding in the two subsequent stages if you wish to use your own data; at a minimum take flats (they are not optional!), dither unless you absolutely can't, and get to know your gear and its idiosyncrasies (have you got the optimal ISO setting?).

The best advice I can give you right now, is to spend some time researching how to produce a clean dataset (not deep - just clean!). Or, if you just love post-processing, grab some datasets from someone else and hone your skill in that area. It's just a matter of changing tack and focusing on the right things. You may well find you will progress much quicker.

I'm sorry for, perhaps, being somewhat blunt, but I just want to make sure you get great enjoyment out of our wonderful hobby and not endless frustration.

Wishing you clear skies and good health!

EDIT: I processed it, just to show there is at least a star field in there, but, per the above advice, giving you the workflow would just teach you how to work around dataset-specific, easily avoidable issues...

dss output.jpg

Edited by jager945
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23 hours ago, Mr niall said:

spent much of last night shooting the Auriga region

 

23 hours ago, Mr niall said:

know ISO 400 seems a bit low but at ISO 800 I get a white screen that is so white I ant actually pick out any individual stars.

I think you pretty much summed it up:

You tried to shoot with a non-modified dslr in a light polluted area, near a full moon. That's a sure recipe for imaging an overexposed star field. I think that if you try the same two weeks from now (no moon), with a light pollution filter, you will get better results. Just make sure you point your 42 mm lens at the Milky Way. And take many exposures. It's the total integration time that counts.

Edit: point at the Milky Way, because for a wide field, this is the most interesting part of the sky, imo. 

Edited by wimvb
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2 hours ago, jager945 said:

I would highly recommend doing as suggested in step 1 of the quick start tutorial, which is perusing the "starting with a good dataset" section.

Yep did that, not sure what your point is there. With the exception of flats, which I didn't believe I needed at 40mm, everything else was done (including a restack with intersection selected on DSS) I would be amazed if they transformed the situation.

If you'd like to explain to me a good dithering procedure for a 15 year old DSLR with a wide angle lens mounted on a clockwork timer then I'm all ears.

2 hours ago, jager945 said:

Your dataset is not really usable in its current state.

That was literally the point of my post; if it isn't any good then I was hoping for advice on perhaps what was causing the issues I was experiencing. The post is even called "Help a Niall" for goodness sake.

2 hours ago, jager945 said:

Apologies in advance, as  I'm about to give some tough love....

2 hours ago, jager945 said:

There are three important parts of astrophotography that need to work in unison. These three things are acquisition, pre-processing, and post-processing. Each step is dependent on the other in that sequence. Bad acquisition will lead to issues during pre-processing and post-processing.

Thanks for being both patronising and condescending. Believe it or not I've been trying to do this for nearly three years with little success. But it is reassuring to know that one quick look at my work is enough for you to make an assessment along the lines of "they've never done this before / or they've no idea what they're doing". Cheers for that. If the solution is to chuck a couple of thousand pounds at mounts at camera's then I'm not really any better off than I was to start with.

Working with good data is easy. I cant get good data. I don't know how to get good data. I don't know why my data isn't good. That's why I'm asking for help. If you'd read my post then you'd see that.

2 hours ago, jager945 said:

The best advice I can give you right now, is to spend some time researching how to produce a clean dataset (not deep - just clean!)

Again - that was literally the point of my post. If I knew what the problem was, I wouldn't be asking for help. That was the point of my post.

2 hours ago, jager945 said:

I'm sorry for, perhaps, being somewhat blunt, but I just want to make sure you get great enjoyment out of our wonderful hobby and not endless frustration

Yeah… not sure you how you think you achieved that. Patronising comments aside you haven't actually said anything other than "your data is rubbish". I'm already at "endless frustration", and I'm following the guidance, repeatedly.

2 hours ago, jager945 said:

I processed it, just to show there is at least a star field in there, but, per the above advice, giving you the workflow would just teach you how to work around dataset-specific, easily avoidable issues...

WHAT ISSUES!!!????

BTW - I did enjoy the irony of "here's a nice version of your picture - but I'm not going to show you how to do it because you're not good enough yet to deserve it". 

Well thanks, that's me feeling like an idiot again. I'll pack the camera away and try again in another few months. If the sum total of the advice is that I'm either useless or an idiot then that advice probably would have been more useful 3 years and several hundred hours of frustrated effort ago. It's not easy asking for help when are clearly so far behind what nearly everyone else seems to be able to achieve, and believe me I doubt many are "trying harder". 

Your post is probably the most demoralising thing I've ever read. Good work.

Edited by Mr niall
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2 minutes ago, wimvb said:

 

I think you pretty much summed it up:

You tried to shoot with a non-modified dslr in a light polluted area, near a full moon. That's a sure recipe for imaging an overexposed star field. I think that if you try the same two weeks from now (no moon), with a light pollution filter, you will get better results. Just make sure you point your 42 mm lens at the Milky Way. And take many exposures. It's the total integration time that counts. 

Thanks Wim, yeah I did have concerns about the moon! I don't think I can get a light pollution filter for my old lumix though? Because it uses MFT lenses I think the screw thread at the front is a weird diameter. Having said that I think maybe putting the money towards investing in a new camera might be the smarter choice! 

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