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MikeWilson

M31: Andromeda galaxy (LRGB)

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My first image post in how many years..?

post-6025-0-46234300-1410132743_thumb.pn

Finally my nomadic-astronomy existence is settling down and I've found a few minutes to obtain this image. I'm not happy with it at all, but what I am happy with is how good the data is considering there's essentially zero light pollution here, no gradients at all even on extreme stretching. Considering what I was used to from Farnborough, the sky could not be more different. It took me two hours to polar align as I kept aligning on the wrong star. All my astro software appeared to have been out of date and needed updating too. It's amazing how much things move on when you're out of the loop.

Anyhow, here's a quick and dirty process of Andromeda just to see what it looks like. I'm fairly new to mono/narrowband processing and I've just aligned everything in Nebulosity 3 and processed in Photoshop. I'm unhappy with the colour of the stars - I didn't blur the RGB layer before sticking luminance on top - and I also forgot to take bias frames in the 2x2 bin too.

L = 35x30s + 7x180s
R = 6x180s
G = 6x180s
B = 5x180s
The stacking was done in DSS, and I'm a perturbed that I didn't get the dust lanes to the core of the galaxy like they show on even individual 30 second subs. 
I've just bought PixInsight (literally ten minutes ago), perhaps there's a tool in there to mask and layer on two luminance layers for HDR processing of bright objects like this?
Any critique is warmly appreciated. Be harsh please!
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Oh yeah, I even left the 2" IDAS LPF on the end of the imaging train - in front of all of the filters. I guess I can probably remove it now and wished I'd remembered to do that before I took this image!

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welcome back to the imaging world.

there looks like some nice detail in the data, but what are the halos around all the stars? i am no expert at proceesing, but it also looks very noisy.

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Thanks Pete,

Those halos; it's my alignment. I just can't get a decent alignment of the RGB channels. It's been a problem for me of the last two years - so I'm going to see if PixInsight can do a better job aligning the RGB channels so that there's not a bit of each colour sticking out at various places. A gaussian blur would probably help here too.

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Good to see you back Mike, I found your blog ages ago when I first got into imaging and found it a great help and enjoyed the 2020 astro podcasts.

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Thanks Pete,

Those halos; it's my alignment. I just can't get a decent alignment of the RGB channels. It's been a problem for me of the last two years - so I'm going to see if PixInsight can do a better job aligning the RGB channels so that there's not a bit of each colour sticking out at various places. A gaussian blur would probably help here too.

i have a similar problem at times with RGB planetary images, its as if the images are slightly different size at the different channels. 

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Thanks Mr Sulaco, sir. Glad to be of help :)

Pete: Did you find a solution? Was it simply a focus issue? Mine is like each channel is slightly >distorted< - it hasn't been a problem with narrowband but with RGB I'm a bit skewed. I'm wondering if it's focus-related somehow but it probably won't matter for a binned RGB layer if it's blurred a bit. The higher resolution luminance gets the correct amount of each colour so it's worth it in the end.

I'm just getting to grips with PixInsight, so I'll post another version up later when I've managed to figure out a slight problem I've got with the LRGB recombination.

Cheers,

Mike

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not really sure i have to be honest, as it only shows up on the disc edges under high zoom when viewing the image.

Edited by bunnygod1

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14997326319_b47e7f4f1e_c.jpg

Updated process using PixInsight. I'm still learning, it's a monster of a tool.

Edited by MikeWilson
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Looking good Mike but it does appear a bit soft, second process is much better!

Any news on 2020Astro popping back up? Such an awesome podcast!

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Looking good Mike but it does appear a bit soft, second process is much better!

Any news on 2020Astro popping back up? Such an awesome podcast!

Thanks, the second process is so much better. I used PixInsight which feels to me like a collection of Photoshop Actions on steroids. Even with my non-existent PixInsight skills I was able to produce an image that is better than I could with Photoshop. Although I had to use NoiseNinja afterwards as I don't understand the noise reduction techniques in PixInsight yet.

The 2020 Astro podcast is back :) Episode 17 was out last weekend which is on image processing.

Mike

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Yes, PI does look intense! I keep meaning to give it a go, although i will probably end up buying it at some point. It has some really nice tools.

Thats awesome about the podcast! I just checked and since i'm still subscribed its sat there all ready downloaded waiting for me to hit play :)

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Do give PI a go; I recommend before you trial it (since the trial is very restrictive - i.e. if you install and don't get around to trialling it you don't get another go beyond the first 45 days) that you have at least one tutorial that you like the look of ready to go with your image data.

I pretty much followed the LRGB processing tutorial steps/workflow to make this image.

I'm glad that you're enjoying the show. There's more episodes to come!

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I am lucky enough to have a second trial license! I downloaded the trial ages ago and never used it so Juan at PI allowed me a second whenever i feel the need to download it, think i'll wait till i have a bunch of data to play with.

Btw, the show was great :) good to hear you guys again

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I've decided that I really like PI. The tutorials are great and it's able to align some fairly distorted frames quite well using the 2-D splines alignment algorithm.

PI is well worth it, although there's a lot of crossover between the various tools; Maxim, PI, AstroArt, etc. I suppose it all depends on what you're doing and how you work. I'm still using Nebulosity 3 for image acquisition as I really like the easy interface, especially for focusing. What I don't like about Nebulosity 3 is that it's got no interface (and the scripting is a bit hit  & miss) for image capture sequencing. I'd quite like to see something like Sequence Generator Pro in there, but for the time being I'm rolling up a sequence in Notepad each time I want to image something.

And I forgot to take darks in 2x2 bin, so there are no darks for the RGB portion of this image.

Now to figure out how to add the Ha data into the LRGB's red channel to bring out the nebulosity in the galaxy!

Thanks for your feedback on the show :) More to come!

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Mike - Nice to see you back again :smiley:!  Your version 2 is a very good advert for PI - I like that one a lot!  I'd been considering buying PI for a LONG time myself, but by the time I decided to press the trigger, i discovered it was only available as 64-bit... and I currently only have a 32-bit laptop :sad:.  When I finally get the chance to upgrade, it'll certainly be on the shopping list (with all the other stuff on the wish list!)

I'm looking forward to seeing a few more from you now that you're obviously back in the saddle... :smiley:.

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