M31

[steviemac500]

It's been a while since I imaged Andromeda so thought I'd have another go. This is 9hrs of Lum and 9hrs combined RGB. Processed in PI. I'm not sure whether to go back and add some shorter exposures to get the core and some HA or maybe extend the framing with a couple of panels? Last time I tried to mosaic this I couldn't get the panels matched without horrible colour gradients on the seams. Hope you like it, comments and criticisms welcomed as always.

Steve

[Giampiero Baggi]

Nice job!

What equipment did you use?

Also, how many calibration frames did you take? I'm interested.

 

[steviemac500]

HI,

ED80 with reducer, Moravian G2-8300, BAADER filters. ZWOASI120MC as guider. My flats consisted of 25 frames each, about 100 darks (not sure, they were taken a while ago) and a super bias. 

[Allinthehead]

Hi Steve. Very nice M31. Since you asked for critique to my eye at least i think you could tone it down a little, it looks a bit overstretched and there's a gradient on the left of the image that could be cropped out. There's some great detail in the galaxy and you managed to get some nice ha regions too. Lots to work with.

[tomato]

A first class result, great colour and detail, the outer fringes are outside the frame but there is enough there in my opinion for it to stand as an image on it’s own.

I have a G2-8300 coupled to a 102 mm Altair APO and a mosaic is definitely needed with this set up on M 31.

[steviemac500]

19 minutes ago, Allinthehead said:

Hi Steve. Very nice M31. Since you asked for critique to my eye at least i think you could tone it down a little, it looks a bit overstretched and there's a gradient on the left of the image that could be cropped out. There's some great detail in the galaxy and you managed to get some nice ha regions too. Lots to work with.

Thanks for the comments I know what you mean about the gradient. I think it’s to do with the file type as it doesn’t exist in Pixinsight as an xsif file but it’s really obvious in this version ?

I wasn’t too sure about the stretching either but if I’d got the whole galaxy i think this level of stretching would have been acceptable as the outer fringes would have been more apparent, especially against the background. Might have to add the extra panels to see ?

[steviemac500]

Having had a look again, there is too much magenta. I’ve also started another two panels for a mosaic to extend the sides of the galaxy. Hopefully no horrible colour gradients this time! ?

[ampleamp]

Since you use Pixinisght, it might be worthwhile trying the use of HDR Multiscale Transformation to open the core a touch. It is very easy to overdo it so care is needed to prevent some (IMO) terrible results. I find 8 layers generally works best for me but I experiment through the range every time. 

Also the dark structure enhance script might work well for you; I usually blur two layers but again, experiment on your own data. 

 

Just remembered about your magenta comment. It is always worthwhile trying this.

Invert the image, run SCNR in green (often around 0.9) and then reinvert the image back to normal. Invertion turns the magenta into green which is then removed by scnr. The trick is what happens when you reinvert and how does everything look? If it works, happy days. If it doesn’t, there are various magenta strings for Pixelmath to try. 

[steviemac500]

13 minutes ago, ampleamp said:

Since you use Pixinisght, it might be worthwhile trying the use of HDR Multiscale Transformation to open the core a touch. It is very easy to overdo it so care is needed to prevent some (IMO) terrible results. I find 8 layers generally works best for me but I experiment through the range every time. 

Also the dark structure enhance script might work well for you; I usually blur two layers but again, experiment on your own data. 

 

Just remembered about your magenta comment. It is always worthwhile trying this.

Invert the image, run SCNR in green (often around 0.9) and then reinvert the image back to normal. Invertion turns the magenta into green which is then removed by scnr. The trick is what happens when you reinvert and how does everything look? If it works, happy days. If it doesn’t, there are various magenta strings for Pixelmath to try. 

Hi, thanks for the tips. I do use HDR but the core needs shorter exposures as well, all the levels made it look a bit odd. I corrected the magenta with a slight curves reduction in red which also helped enhance the blue stars on the fringe. I’m go to reprocess the whole thing when the other panels are completed anyway so I’ve got a few more things to try. ??