Recommendations for learning? I'm getting worse not better!

[CheapAsAstronomer]

Hey all.

Any recommendations for learning image processing? 

After a year, my equipment is better and my acquisition methods are better but my editing skills are getting worse and worse...My images looked better six months ago.

I'm capturing with Sharpcap and editing in Startools before a final tickle in GIMP but I'm always bitterly disappointed 😔

[smashing]

15 minutes ago, CheapAsAstronomer said:

Hey all.

Any recommendations for learning image processing? 

After a year, my equipment is better and my acquisition methods are better but my editing skills are getting worse and worse...My images looked better six months ago.

I'm capturing with Sharpcap and editing in Startools before a final tickle in GIMP but I'm always bitterly disappointed 😔

Watch tutorials on YouTube and follow them...try and try and try again 

[Clarkey]

I have found Startools tricky, especially with less than perfect data. I do still use it for some things but rarely start to finish. There is a very good, but long YouTube video by the developer which is well worth watching. I tend to use APP and Affinity now which I find a good combination. I think there are trial versions of both you could try on some of your existing data to see how you get on. Again there are plenty of tutorials from the developers for both. PS is probably best but I won't pay their sky high monthly charge.

The other thing to consider is that your expectations are probably going up too. I know mine have from when I started. I also tend to reprocessing the same data multiple times until I get a version I like. Quite often the processing takes longer than the capture.

Just keep at it and it will get better. At least that's what I tell myself!!

[CheapAsAstronomer]

13 minutes ago, Clarkey said:

I have found Startools tricky, especially with less than perfect data. I do still use it for some things but rarely start to finish. There is a very good, but long YouTube video by the developer which is well worth watching. I tend to use APP and Affinity now which I find a good combination. I think there are trial versions of both you could try on some of your existing data to see how you get on. Again there are plenty of tutorials from the developers for both. PS is probably best but I won't pay their sky high monthly charge.

The other thing to consider is that your expectations are probably going up too. I know mine have from when I started. I also tend to reprocessing the same data multiple times until I get a version I like. Quite often the processing takes longer than the capture.

Just keep at it and it will get better. At least that's what I tell myself!!

Yeah I guess my expectations are going up!

I might just check out some new software then....

[The Lazy Astronomer]

To help with your processing, Ivo (Startools developer) is usually happy to process your data as a teaching exercise if you contact him (certainly, I've seen many posts on the Startools forum where he has done so).

[CheapAsAstronomer]

5 hours ago, The Lazy Astronomer said:

To help with your processing, Ivo (Startools developer) is usually happy to process your data as a teaching exercise if you contact him (certainly, I've seen many posts on the Startools forum where he has done so).

Ooh there's an idea!

[wimvb]

+1 for letting someone else process your data. And you can also process other's data. Eg, the IKI observatory data that is published here on sgl. This gives you the opportunity to compare your results to others.

[Dazzyt66]

24 minutes ago, wimvb said:

+1 for letting someone else process your data. And you can also process other's data. Eg, the IKI observatory data that is published here on sgl. This gives you the opportunity to compare your results to others.

This is good advice. The best thing I did to learn was use other people’s raw data. There’s quite a few available nowadays. You know that there is something of quality there so you can get to grip with whatever packages you like until you have your own methods worked out. I started with DSS, Registax and Gimp (as I want to do it as cheaply as possible 😊). I tried Startools but couldn’t get to grips with it - although it seems very good. I’m now moving to just Siril and Gimp as I’m on a Mac now and taking the same approach - get some raw data and then watch YouTube tutorials on the packages until I find a workflow that I can cope with 😂

[tomato]

It does indeed help to have a processing expert use your data, and the other approach of using a quality data set is also useful, although I tend to find this a bit discouraging when I can’t achieve the same result as the experts.

My own experience is that I find it much harder to master image processing than data acquisition, I’m sure there are others that find that the reverse is true.

I also think a one processing package fits all solution doesn’t guarantee you the best results, I really like StarTools but sometimes (to my eye) I get a better result with APP and AP.
 

Please take a look at the StarGazine videos on here that cover image  processing, as well as the myriad of video and web based tutorials that are available on the internet. 

[carastro]

If you decide to use Photoshop I have a number of tutorials on You tube which may help.

https://sites.google.com/view/astrophotography-carole-pope/video-tutorials?authuser=0

[scotty38]

@tomato and @Clarkey (and sorry to go slightly OT but think it's relevant) but you both use APP and AP so which bits of processing do you tend to use each package for?

I have got bogged down trialling APP, StarTools, PixInsight etc so I'm trying to stick with Affinity for now but curious as to the bits you do in APP...

[wimvb]

3 hours ago, tomato said:

although I tend to find this a bit discouraging when I can’t achieve the same result as the experts

That’s simply because you’re not an expert yet. Letting someone with more experience work with your data can help to ensure that at least the data acquisition is ok. I used this approach myself, and used the experts result as inspiration, something to thrive for.  AP should be a passtime and a fun activity, not a contest. The only ”contest” I have is the one where I try to beat my own previous achievements. I usually end up being the winner in that contest. 😉

[Padraic M]

I've given Startools many good runs with my data and was never happy with it, although I know that others can get great results from it. All of mine look like I managed to capture a pack of Dalmations being evicted from the ISS. The video tutorials will tell you which buttons to press but not what's happening when you do; or what to change if the results don't automatically look great.

btw while I get better results with top-quality data like the IKI I'm still not achieving what others can do - this suggests to me that my data acquisition can improve, AND my processing skills can also improve. I've already thrown money at it so I can't blame the equipment any more. 🙂

My best results and the best learning came from stacking in DSS, and processing in Gimp (or you could use PS). It's more intuitive although it takes longer, and is a good way to learn what's going on. I've moved on to AstroPixelProcessor for stacking, gradient/LP removal, and colour composition, and Gimp for final tweaking. I find that I can manage APP better now because of the time I put into doing it 'by hand' in Gimp.

 

[tomato]

9 hours ago, scotty38 said:

@tomato and @Clarkey (and sorry to go slightly OT but think it's relevant) but you both use APP and AP so which bits of processing do you tend to use each package for?

I have got bogged down trialling APP, StarTools, PixInsight etc so I'm trying to stick with Affinity for now but curious as to the bits you do in APP...

APP is my default package for calibration and stacking. I will then take the separate channels into StarTools and follow that workflow. If that gives me a ‘Dalmatian Moment’ then I will try combining the channels in APP. If it is my data, the light pollution removal tool is almost always required. I then use the image processing tools on the RHS and save a stretched TIFF file for final tweaking in AP or Gimp. 
 

I think my problem is I don’t apply enough scientific rigour to the process. My approach is currently way too subjective, ‘let’s try a bit of everything’ it needs me to be more disciplined.
 

I start out with the right intentions but inevitably fall into the ‘keep nudging the sliders’ trap every time.

[Clarkey]

10 hours ago, scotty38 said:

@tomato and @Clarkey (and sorry to go slightly OT but think it's relevant) but you both use APP and AP so which bits of processing do you tend to use each package for?

I use APP for stacking and combining the channels, gradient removal and star colour calibration. You can play around with the amount of RGB you put in the data and as it is stretched as you do it, you get a good idea of how it will turn out in the final product. After this I take an unstretched version to Affinity to get the detail and the 'creative bits'. To be honest, in some cases you can do all the work on APP but Affinity has more options to repair and get a the best from the image. I think the gradient removal in APP is excellent. The only negative of APP stacking is that it is slow - or at least it is on my PC. DSS is much quicker. However, the result from APP is better.

The other negative is that it is a bit pricey. But given the amount I spend on AP gear £60 a year for APP is not a biggy.

[jager945]

Indeed, if StarTools is not playing ball with your datasets, then feel free to share one with me (Dropbox, Google Drive, WeTransfer, OneDrive, etc.).

If StarTools needs lots of babysitting, then almost always, the problem is an acquisition issue (bad flats, not dithering, incorrect stacker settings, not linear/virgin anymore etc.). You can find a fairly comprehensive list here.

When evaluating post-processing software, the worst mistake you can make, is judging software on its ability to hide issues. Hiding issues is not what post-processing is about . If that's mostly what you are doing and focused on, then you will not progress.

The best software maximises and protects real celestial signal you have captured. Some common pitfalls;

• Trying to use a gradient removal tool to clean up flat frames issues
• Trying to use levels and curves to hide flat frame issues
• Trying to use noise reduction to remove correlated noise grain and pattern noise (instead of dithering).
• Trying to process channels separately non-linearly
• Applying color balance corrections, deconvolution, gradient removal and other operations after stretching.

...and that's sadly just the tip of the iceberg.

Getting to the point where you can 100% trust - in terms of signal - what you have captured should be your immediate goal. You should not be wondering whether something is faint nebulosity or some smudge or gradient remnant. You should not be wondering if something is a Bok globule or shock front,  or just a smudge or pattern noise.

From there, image processing becomes easy, replicable, "zen" and - for most - fun and rewarding. You can then start learning about what goes into a good image, what is sound signal processing and what isn't.  AP processing is so much more than just pressing the right buttons - that's just the software. Understanding what the software does - and why -  is where things really start. You will then find that a piece of software's eagerness to hide issues is inversely proportional to its sophistication when it comes to preserving signal and faint detail.

Don't think you need particularly deep data either. Not everyone can spend hours under pristine skies. At the end of your night, you just need well calibrated data where the only remaining issue is shot noise and nothing else.

@wimvb made an excellent suggestion; have a look at someone else's dataset and see if there is anything there that stands out to you. Perhaps try processing it and - if that is helpful - see how different software reacts differently. 

Clear skies!

[scotty38]

Thanks for that @tomato, @Clarkey much appreciated and I think I will have another look at APP too

Edited March 31, 2021 by scotty38

[bottletopburly]

I would definitely recommend trying Startools, processing with good data like the Iki observatory data helps ,I can  honestly say you can’t get any easier processing than  with Startools it is really that simple a three yearn old could use it to and as Ivo said if you can’t then there is probably an issue with the data as mentioned, on Startools website there is  a link to Guys notes saying what each module does https://www.startools.org/links--tutorials, there is also a very good unofficial manual  too  very comprehensive http://download.startools.org/StarTools Manual V1_3_5 Unofficial.pdf  and Ivo is always on hand to help if for some reason there’s an issue he will be more than willing to look into the issue . 
Here is a videoing the of a data of M31 I did for someone on Startools forum(their data) that was having issues to give an idea of workflow .

 

[CheapAsAstronomer]

On 31/03/2021 at 23:29, jager945 said:

Indeed, if StarTools is not playing ball with your datasets, then feel free to share one with me (Dropbox, Google Drive, WeTransfer, OneDrive, etc.).

If StarTools needs lots of babysitting, then almost always, the problem is an acquisition issue (bad flats, not dithering, incorrect stacker settings, not linear/virgin anymore etc.). You can find a fairly comprehensive list here.

When evaluating post-processing software, the worst mistake you can make, is judging software on its ability to hide issues. Hiding issues is not what post-processing is about . If that's mostly what you are doing and focused on, then you will not progress.

The best software maximises and protects real celestial signal you have captured. Some common pitfalls;

• Trying to use a gradient removal tool to clean up flat frames issues
• Trying to use levels and curves to hide flat frame issues
• Trying to use noise reduction to remove correlated noise grain and pattern noise (instead of dithering).
• Trying to process channels separately non-linearly
• Applying color balance corrections, deconvolution, gradient removal and other operations after stretching.

...and that's sadly just the tip of the iceberg.

Getting to the point where you can 100% trust - in terms of signal - what you have captured should be your immediate goal. You should not be wondering whether something is faint nebulosity or some smudge or gradient remnant. You should not be wondering if something is a Bok globule or shock front,  or just a smudge or pattern noise.

From there, image processing becomes easy, replicable, "zen" and - for most - fun and rewarding. You can then start learning about what goes into a good image, what is sound signal processing and what isn't.  AP processing is so much more than just pressing the right buttons - that's just the software. Understanding what the software does - and why -  is where things really start. You will then find that a piece of software's eagerness to hide issues is inversely proportional to its sophistication when it comes to preserving signal and faint detail.

Don't think you need particularly deep data either. Not everyone can spend hours under pristine skies. At the end of your night, you just need well calibrated data where the only remaining issue is shot noise and nothing else.

@wimvb made an excellent suggestion; have a look at someone else's dataset and see if there is anything there that stands out to you. Perhaps try processing it and - if that is helpful - see how different software reacts differently. 

Clear skies!

Awesome post and much to learn from it.