M82 LHaRGB

[geoflewis]

Here's my 2nd image of 2020, mostly captured later on the same recent run of clear nights that I was imaging IC342, though I did capture the Ha earlier in Dec when the Moon was up.

The image comprises L=21x600s; Ha=9x900s; RGB(each)=24x300s, all captured through my C14 XLT plus Optec x0.67 telecompressor, with my QSI583wsg-5 camera using Astronomic filters . I would have liked more Ha, but since the forecast for the next few days is not good, I thought I'd take a look at what I already had, so here it is...

Thanks for looking.

 

 

 

Edited January 23, 2020 by geoflewis
added gear

[tooth_dr]

What sort of FL are we talking here!  That's pretty freaking awesome Geof.

[carastro]

Excellent result Geof.

Carole

[don4l]

Superb!

[geoflewis]

3 minutes ago, carastro said:

Excellent result Geof.

Carole

 

1 minute ago, don4l said:

Superb!

Thanks both, I'm glad I processed what I had. Maybe I can start on another target next clear skies, though I may also go back to shoot some Ha for IC342.

[Davey-T]

That's a beauty Geoff, well done 

Dave

[geoflewis]

24 minutes ago, tooth_dr said:

What sort of FL are we talking here!  That's pretty freaking awesome Geof.

Many thanks @tooth_dr. My bad, I should have listed the gear when I posted it, so I'll go back and add that. I was using a C14 with a x0.67 telecompressor, giving an effective focal length of approx 2.6m.

[geoflewis]

8 minutes ago, Davey-T said:

That's a beauty Geoff, well done 

Dave

Thanks Dave

[Sunshine]

I cant say i have ever seen an amateur shot of M82 so detailed, Beautiful shot of this starburst galaxy.

[geoflewis]

9 minutes ago, Sunshine said:

I cant say i have ever seen an amateur shot of M82 so detailed, Beautiful shot of this starburst galaxy.

Wow, many thanks for those very generous comments @Sunshine.

[cuivenion]

Hi Geoff, it's a great shot but it looks like something went wrong processing wise. Did you use morphological transform or other star reduction without using a mask? The galaxy has a weird blurring crystalline effect that I've seen before when I've done this.

[geoflewis]

6 minutes ago, cuivenion said:

Hi Geoff, it's a great shot but it looks like something went wrong processing wise. Did you use morphological transform or other star reduction without using a mask? The galaxy has a weird blurring crystalline effect that I've seen before when I've done this.

Thanks @cuivenion,

I have no idea what morphological transform is, but I did do some star size reduction using Noel's actions in PS. Can you explain more about what it is that you are seeing, maybe crop a specific region, so that I can take a better look.

Many thanks

[cuivenion]

Hi, morphological transform is the Pixinsight version of star reduction. It's basically effecting most of the detail in the galaxy, I don't use photoshop so don't know how you'd go about protecting the galaxy and background. Try a version without the star reduction and look at the image at full resolution and you should notice the difference. I would add I can't wait to look at the image at full res with that effect removed, it's a cracker.

[Craney]

Top quality shot.   This has inspired me to go get it with the 8"SCT.

Edited January 23, 2020 by Craney

[geoflewis]

27 minutes ago, cuivenion said:

Hi, morphological transform is the Pixinsight version of star reduction. It's basically effecting most of the detail in the galaxy, I don't use photoshop so don't know how you'd go about protecting the galaxy and background. Try a version without the star reduction and look at the image at full resolution and you should notice the difference. I would add I can't wait to look at the image at full res with that effect removed, it's a cracker.

Thanks for the explanation. Here's the Tiff image before I took it into photoshop.

M82_LHaRGB_IP.tif

All the processing up to that point was using ImagesPlus astro processing software, but even there I did run star reduction on the lum channel before blending with the HaRGB, so is this still showing the artefacts as I can't see much difference in the galaxy, other than it is softer as I hadn't applied any sharpening at that point. It doesn't help that I don't know what I'm looking for 🥴. I'll have to go back to the start and see if I can identify what and where the issue arises. Any additional pointers would certainly help please.

[geoflewis]

31 minutes ago, Craney said:

Top quality shot.   This has inspired me to go get it with the 8"SCT.

Thanks Craney, go for it 😉. I look forward to seeing it.

[cuivenion]

Hi, the artifacts are in the tiff, as you said you applied star reduction in the luminance. Here's an example using my M82. Unfortunately you cant see the Ha tendrils as well from the centre as I don't have your data but you can see how the star reduction blurs the details when applied without a mask or other protection.

The three images are with no star reduction, one iteration, and two iterations. Again I'm not getting exactly the same effect because I'm using a slightly different process and your data is a lot better, but hopefully you can see what I mean.

[geoflewis]

14 minutes ago, cuivenion said:

The three images are with no star reduction, one iteration, and two iterations. Again I'm not getting exactly the same effect because I'm using a slightly different process and your data is a lot better, but hopefully you can see what I mean.

Thanks, I can now see what you are referring to, so that gives me something to watch out for. That said I'm not sure how to perform star reduction in ImagesPlus with a mask, so maybe I'll leave it out completely and see what I get. It's always great to get constructive criticism, so thanks for pointing it out.

[cuivenion]

No probs, There will be a way to protect the data, Pixinsight uses masks, other software may be different. Hopefully someone familier with ImagePlus and Photoshop can give some advice.

[geoflewis]

30 minutes ago, cuivenion said:

No probs, There will be a way to protect the data, Pixinsight uses masks, other software may be different. Hopefully someone familier with ImagePlus and Photoshop can give some advice.

So you are right, it is in the lum processing. Here is the HaRGB on its own (says LRGB, but is actually HaRGB), plus the Lum before and after star reduction.

M82_MixLRGB-Hue_IP.tif

M82_L_CombineFilesSigMed_NoStarRed.tif

M82_L_IP.tif

Now I need to learn how to process this better. Great catch and thanks for putting me onto it...

....and here is  the lum with the galaxy masked star reduction...

M82_L_Masked Star Reduction.tif

Edited January 24, 2020 by geoflewis
added masked star reduction lum

[geoflewis]

So now I have something to do tomorrow......

[geoflewis]

14 hours ago, cuivenion said:

No probs, There will be a way to protect the data, Pixinsight uses masks, other software may be different. Hopefully someone familier with ImagePlus and Photoshop can give some advice.

Hi @cuivenion, so I'm much more familiar with ImagesPlus (IP) than PS, so I decided to teach myself / relearn how to create & use masks there, then did all the processing for this version in IP, so here it is. It took a couple of attempts to get something that I was satisfied with, hence the v3...

M82_LHaRGB(v3)_IP.tif

I think this version protects the galaxy details better, but please let me know what you think.

Many thanks

[cuivenion]

4 hours ago, geoflewis said:

Hi @cuivenion, so I'm much more familiar with ImagesPlus (IP) than PS, so I decided to teach myself / relearn how to create & use masks there, then did all the processing for this version in IP, so here it is. It took a couple of attempts to get something that I was satisfied with, hence the v3...

M82_LHaRGB(v3)_IP.tif 11.21 MB · 4 downloads

I think this version protects the galaxy details better, but please let me know what you think.

Many thanks

It's looking good, the problem seems to have gone. You do seem to have a strange artifact either side of the galaxy's center:

But I'm not sure what is causing that. That being said it's quite hard to see the new artifacts unless you zoom in and the it's a great image. Nice one mate.

[geoflewis]

16 minutes ago, cuivenion said:

It's looking good, the problem seems to have gone. You do seem to have a strange artifact either side of the galaxy's center:

But I'm not sure what is causing that. That being said it's quite hard to see the new artifacts unless you zoom in and the it's a great image. Nice one mate.

Thanks, yes I also saw those artefacts, which I think came from me trying to boost the colour in the star burst region. Layering the luminance washed out a lot of the colour in the galaxy so I suspect my attempt to rectify that was rather clumsy. I keep going back to it, but so far haven’t found a solution that I prefer.

Edited January 24, 2020 by geoflewis

[simmo39]

V nice, lots of detail!