My first attempt at M31

[StuartT]

Finally had some clear last night, so I tried out M31.

This was done with my Esprit 150ED APO (focal reducer taking it down to f/5/6) using NINA and a ASI 2600MC. No filters. Processed using default settings in APP.

total integration time 59min. 

Any tips on whether I could stretch any more out of this would be welcome.

M31-RGB-session_1.fits

[michael.h.f.wilkinson]

Very nice result. Like the very natural processing.I am not sure if any further stretching would help

[vlaiv]

I think it is stretched good. Maybe handling of background could be slightly better. There is gradient in the image in background - it can be removed. That produces a bit more contrast on the galaxy - like this:

[StuartT]

4 minutes ago, vlaiv said:

I think it is stretched good. Maybe handling of background could be slightly better. There is gradient in the image in background - it can be removed. That produces a bit more contrast on the galaxy - like this:

Thanks vlaiv. Can I ask what exactly you did to remove the gradient?

[vlaiv]

1 minute ago, StuartT said:

Thanks vlaiv. Can I ask what exactly you did to remove the gradient?

I loaded linear fits file that you provided in ImageJ and I ran my own plugin that works similar to gradient xterminator and similar tools for background extraction. I bin image x2 to gain some of SNR (it's a bit over sampled so no detail was lost).

Then I loaded image to Gimp and did very basic stretch. I did not color manage it at all, so colors are questionable. In the end I did very basic selective noise suppression.

[alacant]

2 hours ago, StuartT said:

stretch any more out of this

Hi

Yeah. There's loads more to be had. The best m31 of the season so far i'd say.

Here's my 5 minute demonstration. Add another 59 minutes and you'd have a winner on your hands:)

 

 

 

 

Edited September 6, 2021 by alacant

[StuartT]

4 minutes ago, alacant said:

Hi

Yeah. There's loads more to be had. The best m31 of the season so far i'd say.

Here's my 5 minute attempt: Add another 59 minutes and you'd have a winner on your hands:)

 

 

 

 

wow! what did you do??

[vlaiv]

Well, if you trade resolution for SNR and really push data - you can get it to stretch further, but I don't think I personally prefer to see data stretched beyond what is really capable of showing:

[StuartT]

Thanks vlaiv. Yes, I can see your point. What I need is more data. Only an hour is not so much, I guess

[tomato]

Yes, the core is bright but you do need lots of integration time to reveal the detail in the numerous dust lanes, more subs benefit the colour also. It is a big target so I think of imaging it as an extended diffuse nebula.

A very nice M31 BTW.

[alacant]

1 hour ago, StuartT said:

what did you do

Hi

I found detail, colour and more galaxy.

Even in 59 minutes, there's a lot there already, hence my recommendation of shooting another session.

Modern astro apps give you the possibility of quickly visualising what's there. In so doing they save you time and help you decide whether it's worth continuing.

Cheers and looking forward to seeing the final version.

[StuartT]

13 hours ago, alacant said:

I found detail, colour and more galaxy.

Sure, but I meant what was your technique(s) to get the extra detail?

[alacant]

59 minutes ago, StuartT said:

get the extra detail

Ah, ok. Sorry.

I used StarTools. No levels. No curves. No graphs... A good tagline would be 'Bringing astro-processing into the 2020s'!

Cheers

Edited September 7, 2021 by alacant

[StuartT]

Ok, so I added another hour of data to this last night. I think it's better. Also removed the gradient with AstroflatPro

 

M31-RGB-session_1-1.fits