If you fancy a laugh take a look at my M31

[beamer3.6m]

So I captured a new set of frames without the CLS filter.

These remain 180s lights and I also ran 60 biases frames and used my lights from the previous session as nothing had changed in the imaging train (I know this is not ideal).

I then ran it through Siril without Darks, as suggested, and this is the result... which to my eyes is improved. I can see some banding in the image but the galaxy is more evident and there certainly seems to be more data in the image to work with... 

I attach the PNG and also the .TIFF should anyone want to play with it.

M31.tif

Edited September 19, 2022 by beamer3.6m

[vlaiv]

13 hours ago, beamer3.6m said:

which to my eyes is improved

It certainly is an improvement.

13 hours ago, beamer3.6m said:

I attach the PNG and also the .TIFF should anyone want to play with it.

Tiff is also processed version.

Maybe it would be better to include linear stacked data rather than processed.

[beamer3.6m]

5 minutes ago, vlaiv said:

It certainly is an improvement.

Tiff is also processed version.

Maybe it would be better to include linear stacked data rather than processed.

Good point. I will get that sorted so just the stacked tiff is available with no processing

[beamer3.6m]

Here is the linear .Tiff file without anything done to it other than stacking (no darks included as suggested).

 

 

M31 raw stack.tif

[Elp]

Your latest data is better, though the first one wasn't too bad:

On such a bright target like Andromeda you should take short (30-60s) exposures, so when you stack there are more frames to average out the noise.

[Phillyo]

Not a bad first attempt for sure!! I had a play with the data and it's not that bad, but yes an astronomy specific camera will definitely help.

Added your image and my first attempt with my ASI533 and Samyang 135 lens. 

[beamer3.6m]

9 minutes ago, Phillyo said:

Not a bad first attempt for sure!! I had a play with the data and it's not that bad, but yes an astronomy specific camera will definitely help.

Added your image and my first attempt with my ASI533 and Samyang 135 lens. 

 

If this is from my data, how did you get it so smooth... What did you do to process it?

Your image is amazing by the way!

[Iem1]

This is not bad data at all! You should be proud of the image you captured  

I also had a go at processing it as I have not been able to get out and enjoy the recent clear nights.

Take a look at Sirils banding reduction and background extraction tools, they will help clear up the image and deal with gradients pretty effectively!

[Phillyo]

7 hours ago, beamer3.6m said:

If this is from my data, how did you get it so smooth... What did you do to process it?

Your image is amazing by the way!

Yes, your data. I used pixinsight. DBE, Canon banding removal script, background neutralisation, EZ Soft Stretch, StarXterminator then a range mask over the galaxy, some curves adjustment before adding the stars back in and reducing them a little bit  

[beamer3.6m]

16 minutes ago, Phillyo said:

Yes, your data. I used pixinsight. DBE, Canon banding removal script, background neutralisation, EZ Soft Stretch, StarXterminator then a range mask over the galaxy, some curves adjustment before adding the stars back in and reducing them a little bit  

So much to learn!!!

[ONIKKINEN]

Ran it through Siril and PS too, this is what i got out of it:

You have captured some pretty nice data for a beginner, you have done well!

[beamer3.6m]

1 hour ago, ONIKKINEN said:

Ran it through Siril and PS too, this is what i got out of it:

You have captured some pretty nice data for a beginner, you have done well!

Wow, im impressed...

I think I'm ok getting the data its the processing which I lack any skill at.

I use Siril to stack but the poststack processing just confuses the hell out of me... WHat you have managed to pull out of the data is amazing

[ONIKKINEN]

16 hours ago, beamer3.6m said:

Wow, im impressed...

I think I'm ok getting the data its the processing which I lack any skill at.

I use Siril to stack but the poststack processing just confuses the hell out of me... WHat you have managed to pull out of the data is amazing

The processing part takes time to understand enough for it to start making sense. You'll develop a standard workflow at some point and then its just another hurdle in the hobby, but from what i can tell the development of processing skills doesn't stop and i tend to dislike images i processed just a few months ago. But going back to them and seeing if it could be improved is also a great way to develop the skills. Im guessing the more experienced folks here have been on the processing grind for decades, and it shows. I am definitely not an expert on processing, but if you want some clues to follow then here is what i did to this image, in Siril and photoshop.

Siril:

1. crop stacking artifacts out (funny corners that have not received the full integration)
2. Banding reduction (not necessary if there is no banding)
3. Background extraction, which is easy to work with since the object of interest is small and in the center in this case
4. Colour calibration. I used manual colour calibration with the core of M31 as the white point source. This way the image turns a bit too blue, but i adjusted it later. Photometric colour calibration works 95% of the times, this was one of the times where i felt it did not.
5. Remove green noise (also not always necessary)
6. Stretch, first with Asinh transformation then with histogram transformation until the galaxy OR stars look nice, often not possible to have both. The part that does not look nice can be adjusted later with starless processing.

Points 1, 3, 4 and 6, in that order, is what gets any image 90% done and the rest is icing on the cake. Try it out in Siril! Although in this case banding reduction was necessary, but i would try to do that before stacking and registration on the calibrated files.

Photoshop:

1. Create starless image using StarXterminator (paid plugin, you can also use the free Starnet++V2, which is as good or better, they are competing and not always clear which is better)
2. Create stars-only image by subtracting the starless image from the original.
3. De-stretch the stars-only image a little bit to "mute" them a bit and bring the galaxy forward. Also applied a little sharpening to them, to make them a little bit tighter.
4. Select the background of the starless image with the color range tool and desaturate it. This is a very effective way to reduce noise visually, without actually doing any denoising.
5. Adjust the colourbalance and saturation of both layers to what i think looks close to realistic, while also being visually pleasing. This part is kind of subjective and you'll get 5 different opinions from 4 different people if you ask what is correct.
6. Merge layers using using the "screen" mode and done.

Thought it might be interesting to compare the just Siril processed image and the final version. The Siril part (left) of the processing often takes just a few minutes and gets the image 90% done, the photoshop part for the final 10%, well its up to you how long to spend on it, but often i find that almost all of the time i spend processing is in that part.