M42 - reworked using Pixinsight

[swag72]

This M42 data was collected a couple of weeks ago. I have recently downloaded Pixinsight for a look see and decided to rework the M42 data I had used before. I am pleased with the result of this edit, and continue to be impressed with this programme.

[peter shah]

beautifully processed....looks very natural and the core detail blends nicely

ive not used pixinsight....keep meaning to give it a whirl

[swag72]

Thank you very much Peter. The work that you post on here and your website is awesome. Your images are a real inspiration.

[Beyond_Vision]

You are making great progress Sara keep up the good work, an image to be proud of

Regards

Kevin

[harry page]

Hi

I can see you are moving forward

The stars are a bit wonkey in places , and I can see a sat trail as well plus looks like a sat flare this image has everything

Perhapes overstretched very slightley

Practice makes perfect

Harry

[swag72]

Thanks Kevin and Harry. Again followed your video tuts Harry - Was hoping to do it all myself, but things just went very wrong!! Any suggestions you have for dealing with the issues you mention? I am sure I'll have them all in other images!!! I can see the satellite trails now, but couldn't see them in the original or the first PS edit!

[jgs001]

Very nicely done Sara. For the sat trails, use something like Kappa Sigma or Kappa Sigma Median stacking in DSS..

KS - drops the pixel value of the outlier (the sat trail)

KSM - replaces the pixel value of the outlier with the median value, which according to what I read the other day is a more robust method of processing (whatever that means )

As for the stars, your field flattener I think will sort that. This looks like a crop based on the edge stars, but use the lens correction filter in PS, that can help a lot with the edge stars.

[swag72]

Thanks John - Have done so so many stacks that I haven't got a clue anymore what settings I used!! Will remember to use KSM next time I have some data to stack!

You know that you are responsible for this don't you? Without your help I wouldn't have kept the scope and mount out of their boxes!!

[jgs001]

[harry page]

Hi

as mentioned a sigma clip will remove sat trails and such like , be aware that this kind of reject works best with 10 or more images that have been dithered

As for the stars try and sort out the flattner , makes life so much easier.

What went wrong for you

Harry

Thanks Kevin and Harry. Again followed your video tuts Harry - Was hoping to do it all myself, but things just went very wrong!! Any suggestions you have for dealing with the issues you mention? I am sure I'll have them all in other images!!! I can see the satellite trails now, but couldn't see them in the original or the first PS edit!

[swag72]

...

What went wrong for you

Thanks Harry - I will look at getting some new data for M42 - This was only my second capture afterall!! I just had some time and wanted to see how much of your tuts I remembered from my 1st go in PI.

Well, it started going wrong at the histogram transformation stage - when I wasn't working from the linear data!! Anyway, went baclk through the vids and got it sorted!!

[ashworthacca]

Hi

as mentioned a sigma clip will remove sat trails and such like , be aware that this kind of reject works best with 10 or more images that have been dithered

As for the stars try and sort out the flattner , makes life so much easier.

What went wrong for you

Harry

I've always meant to ask but what does "dithered" mean and how do you know if a photo has or hasn't been??

[ashworthacca]

Sara, that's a lovely M42, very smooth processing....great stuff!

[jgs001]

Dithered means that the scope was moved a little between frames. When guiding this means the hot pixels shift around and the sigma clip methods can remove them. Phd and nebulosity work together to do this. I've not tried it yet. I'm also sure that's why my alt az and unguided mages didn't show many hot pixels as the tracking wasn't so accurate.

[ashworthacca]

Dithered means that the scope was moved a little between frames. When guiding this means the hot pixels shift around and the sigma clip methods can remove them. Phd and nebulosity work together to do this. I've not tried it yet. I'm also sure that's why my alt az and unguided mages didn't show many hot pixels as the tracking wasn't so accurate.

Ah, thanks John.

[harry page]

Hi

The man is right

Very very highley recomended

Harry

Dithered means that the scope was moved a little between frames. When guiding this means the hot pixels shift around and the sigma clip methods can remove them. Phd and nebulosity work together to do this. I've not tried it yet. I'm also sure that's why my alt az and unguided mages didn't show many hot pixels as the tracking wasn't so accurate.

[ollypenrice]

Splendid core, smooth and seamless.

As for the fixes, am I allowed to mention Ps on this thread?? (Head down, Harry's coming...)

In Ps Healing Brush will loose the trail.

To round up stars I have written a simple PS action that starts by selecting a star with the magic wand. Then;

Select-Modify-Expand by about 4.

Alt Ctrl D - Feather by about 2.

Filter-Blur-Radial Blur (Spin, best quality, 100 percent)

Deselect. (Don't forget this one).

Once recorded the action plays in a trice on a star selected with the wand. Some need a second hit.

Maybe PI can do something as well?

Olly