In praise of StarTools Star repair tool.

[tomato]

A little while ago I attempted to capture M16 in the brief window (60 mins or so) I have from my location. The first subs told me I had a horrendous optical aberration  on the RASA/camera setup but in true BJ fashion I carried on regardless. I thought I would see just how good the star repair module is in StarTools and was very impressed with the job that it did. 

Now let me say I don't condone poor camera alignment for one second, and I will endeavour to fix this before I image again, but for folks just setting out on the imaging journey who have to get the other 99+ things working, don't chuck your subs in the bin, the software can give you something that you can show your friends and family, even if you wouldn't submit it for an APOD.

Original Stack (crop)

Final Processed Image 

[happy-kat]

That's a super correction on those star shapes, quite amazing

[tomato]

1 hour ago, happy-kat said:

That's a super correction on those star shapes, quite amazing

Agreed, I thought the swarm of Pac-Man shaped stars would be too much for it but the tool did a decent job. Of course, the aberration is there in the nebula detail, which isn’t as straightforward to correct, so I do need to fix it at source.

[LuckieEddie]

Wow. Can you elaborate on the "Star repair" module workflow please?

[tomato]

19 hours ago, LuckieEddie said:

Wow. Can you elaborate on the "Star repair" module workflow please?

Sure, I follow the default module workflow in StarTools, so I don’t use the repair function until right at the end. After first creating a star mask (mask-auto-stars, I usually need to shrink the mask with one iteration), I open the repair module and select the redistribution algorithm, use core from average distribution.

 

[gorann]

Impressive Steve! So I downloaded the Star Tool trial and tried to fix stars in a RASA8 image (ASI2600MC with IDAS NBZ). I have zero experience with this program so I immedeately got stuck when I tried to make a star mask. The image was either all green or I saw no green. So nothing looking like a star mask. Before I make a major effort of figuring out how it works, I wonder if I could ask you to try the Star repair on my image. It has quite eggy stars in the corners, and if they can be easily fixed with this method you would have convinced and motivated me of making an effort to understand how to do it myself. So far I have been fixing eggy stars in PS but that is quite a time consuming process.

The image (Sh2-160) has been moderately stretched, so it is not in the linear stage.

Cheers, Göran

20220423-24 Sh2-160 RASA1 PS1(curves+GXMM+flipped).tif

[tomato]

On 10/07/2022 at 09:23, gorann said:

Impressive Steve! So I downloaded the Star Tool trial and tried to fix stars in a RASA8 image (ASI2600MC with IDAS NBZ). I have zero experience with this program so I immedeately got stuck when I tried to make a star mask. The image was either all green or I saw no green. So nothing looking like a star mask. Before I make a major effort of figuring out how it works, I wonder if I could ask you to try the Star repair on my image. It has quite eggy stars in the corners, and if they can be easily fixed with this method you would have convinced and motivated me of making an effort to understand how to do it myself. So far I have been fixing eggy stars in PS but that is quite a time consuming process.

The image (Sh2-160) has been moderately stretched, so it is not in the linear stage.

Cheers, Göran

20220423-24 Sh2-160 RASA1 PS1(curves+GXMM+flipped).tif 146.39 MB · 4 downloads

Hi Goran, 

Apologies for the delay, I got a bit wrapped up in the JWST images reveal...

Here is a before and after cropped corner of your image after applying the StarTools Repair 'Warp' option, using default settings. Your star aberration was much less severe than mine so I think this more subtle tool was the best option. To create the mask I used Mask - Auto -Stars and used the default mask created. I'm sure the result could be improved a little with a bit more work.

Before

After

 

[gorann]

Thanks Steve! That is impressive and convinced me to have another attempt on Star Tools.

[gorann]

I got it to work! So now I have bought Star Tools, even if I maybe just will use it for fixing stars.

[tomato]

Good to hear! It also has a great noise reduction tool which I use a lot with my short integration times although NoiseXterminator currently has the edge at the moment IMHO.

Edited July 13, 2022 by tomato
Typo fix