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Yet another Andromeda Galaxy


Laurin Dave
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Its been two years since I last imaged it so I thought it was about time to go back to M31. This image was captured over the last two nights from Berkshire UK using an Esprit100/SX46 for LRGB and a GT71/ASI1600 for Ha on a Mesu. 6hrs Lum, 3hrs Red and Green, 4hrs Blue and 13 hrs Ha.  Processed in Pixinsight, APP and Photoshop.  For the pixel peepers the camera is a bit heavy for the stock focuser and there's a bit of tilt showing in the corners.   I've also posted the Ha data which shows the vast number of emission regions within the spiral arms which extend out beyond the corners of the frame.

Thanks for looking

Dave

M31_L_HaRGB_Final_15Sept20_50pc.thumb.jpg.62fc5cf462285934cb1761c375d42aff.jpg

 

M31_Ha_Int_All_HT_DBE_levels_DSNR_registered_Levels_50pc.thumb.jpg.54bed72a0d28dff109c37c0ff6ec9af1.jpg

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Excellent result Dave! I would be tempted to increase the contrast in the details a bit (e.g. HiPass filtering), looks like the core at least have more structures to show. But that is me and soft is nice too and your image is certainly very pleasing to the eye.

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5 minutes ago, gorann said:

Excellent result Dave! I would be tempted to increase the contrast in the details a bit (e.g. HiPass filtering), looks like the core at least have more structures to show. But that is me and soft is nice too and your image is certainly very pleasing to the eye.

Thanks Goran...  early days in its processing journey, no doubt I shall develop many revisions!  I shall have to figure out how to do HiPass filtering,   I did just try Noels Local Contrast Enhancement which also brings out the dust lanes

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Hi pass filtering and Noels LCE are both excellent and I sometimes use a little of both. For high pass filtering, I usually use a setting around 90 and then blend the filtered image with blend mode Soft Light to the background (or background copy). I then do a Merge Down. Then to avoid getting bloated stars I use Select -> Color Range and aim the picker for a star. Then expand the selection 1-4 pixels and Invert the whole selection before copying it. That way I get only the structures copied and not bright stars (so a star free selection). Paste that copy as a layer on a duplicate of the image and use the paint bruch to apply where desired.

Edited by gorann
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1 hour ago, tomato said:

That’s a great Andromeda, lovely colour rendition and I love the Ha highlights.

I’m 3 panels into my 12 panel mosaic, it might be done by Christmas...

Thanks....  I thought you'd decided to do it with your new RASA...  I'd thought about a two panel mosaic to see if I could get the extensions but thought better of it when I saw the gradients in the Luminance and how faint the outer arms are from here.. (Bortle4/5)

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1 hour ago, alan potts said:

Absolutely superb, though I had not seen much of you, too busy with this I see. A really great image and very nicely processed in my humble opinion.

Alan

Thanks Alan..    it's either not been dark or cloudy here for ages :(   

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M31_L_HaRGB_Final_16Sept20_V1.thumb.jpg.03e9a157b0278d4cfe2674bd5c5d6853.jpg

16 hours ago, gorann said:

Hi pass filtering and Noels LCE are both excellent and I sometimes use a little of both. For high pass filtering, I usually use a setting around 90 and then blend the filtered image with blend mode Soft Light to the background (or background copy). I then do a Merge Down. Then to avoid getting bloated stars I use Select -> Color Range and aim the picker for a star. Then expand the selection 1-4 pixels and Invert the whole selection before copying it. That way I get only the structures copied and not bright stars (so a star free selection). Paste that copy as a layer on a duplicate of the image and use the paint bruch to apply where desired.

Here it is as suggested....  full size this time 

 

 

Edited by Laurin Dave
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Superb!

The mosaic project may be a bit bizarre but I want to see the difference between a 100 min OSC RASA 8 F2 image vs 48 hrs(?)  of LRGB CCD data from the F7 dual rig. I do expect the mosaic to be better, but the question is by how much?

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6 minutes ago, tomato said:

Superb!

The mosaic project may be a bit bizarre but I want to see the difference between a 100 min OSC RASA 8 F2 image vs 48 hrs(?)  of LRGB CCD data from the F7 dual rig. I do expect the mosaic to be better, but the question is by how much?

That'll be interesting,  there'll be a difference but whether when looking at the whole image rather than zoomed in it'll be noticeable I don't know.   If I were you to start with I'd just do one area and blend it in... the star cloud NGC206 in Andromeda springs to mind

I started a 4 panel mosaic of the Heart using my Esprit150 with the SX46 and Esprit 100 with the ASI1600..  despite being warned off it...  I got 120 hrs of data (60 per scope) before I got bored and the galaxies turned up , the narrow band stuff was fine(ish) but putting the RGB together was impossible owing to gradients and it was overhead !...  One to finish this year with the Esprit100/SX46

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Yes, I may be asking too much from a Bortle 4 sky, I  could take a look at the first few panels and see if I am on a hiding to nothing with the gradients.

It would be nice to have a run of clear moonless nights to get it done, I don’t ask for much.

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2 hours ago, Laurin Dave said:

Here it is as suggested....  full size this time 

M31_L_HaRGB_Final_15Sept20_LCE_BC_Merge.thumb.jpg.8ad431e435b78cdb8de17a01386d04f0.jpg

 

That is a truely great looking rendation of our neigbour Dave!

I am sure that you all are right in that a well done mosaic with longer FL telescopes would beat a RASA or Epsilon image (and even super expensive Riccardi-Honders), but as noted by tomato, only if pixel peeping. We are all victims of the possibilty of zooming in on images and see how deep they are going. It is like standing in an art gallery with a magnifying glass. Personally I am right now for making images that stand their ground on the distance they should normally be viewed at (which is 30 - 40 cm from a 20 - 30" computer screen). If I want to get really close to a distant galaxy I will use my 2m to 3.5 m FL SCTs, and if I want to capture a big area of nebulosity I use the RASA or even the Samyang 135. Inbetween that it will be my 5 - 6" refractors. I do admire those of us with the patience of doing 10 - 20 (or more) frames mosaics, and those zoomable images are extremey useful for the rest of us to find tagets, but they can only be fully appreciated on a computer where you can zoom in. And for that we have also invaluable tools like Aladin Sky Atlas that is actually giving us a free mosaic of it all.

Edited by gorann
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