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swag72

M63 - The Sunflower galaxy

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This is the first completed galaxy image on the C9.25 at it's native focal length and at f10. I would have liked to capture some long luminance subs to get the tidal waves that surround this galaxy, but there wasn't room in the field of view (never quite satisfied are we? :smiley:)

I welcome all feedback - Do you think it's too saturated? Too bright?

Details:

M: Avalon Linear fast reverse

T: Celestron C9.25

C: Atik 460EXM with Baader filters and 3nm Ha

69x300s L

51x150s R, G and B

13x1800s Ha

Total integration time 18:38

post-5681-0-74966400-1398364743_thumb.jp

You can see a larger version here http://swagastro.weebly.com/uploads/2/3/3/7/23377322/m63.jpg

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This is the first completed galaxy image on the C9.25 at it's native focal length and at f10. I would have liked to capture some long luminance subs to get the tidal waves that surround this galaxy, but there wasn't room in the field of view (never quite satisfied are we? :smiley:)

I welcome all feedback - Do you think it's too saturated? Too bright?

Details:

M: Avalon Linear fast reverse

T: Celestron C9.25

C: Atik 460EXM with Baader filters and 3nm Ha

69x300s L

51x150s R, G and B

13x1800s Ha

Total integration time 18:38

attachicon.gifM63_SGL.jpg

You can see a larger version here http://swagastro.weebly.com/uploads/2/3/3/7/23377322/m63.jpg

 18 hours, i wish for 18 mins at the scope..........lol

very nice, shows putting the time in pays dividens.....exellent.

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Wow, well done. As said above 18+ hrs. Well done on the dedication front alone and the image is fantastic. How many nights was the data captured over?

Ian

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Thanks both! This was probably 4 nights in total - Not too long and ideally I should have got more :grin:

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How did the 3nm Ha work out?

Judging from the red shift of a couple of galaxies I looked at I decided I wouldn't even try such a narrow pass band on galaxies as it reduced the transmission to around 50% or less.

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Congratulations on the first final result - most satisfying! It's a cracking image too. The detail in the core is wonderful and just shows, again, that the more time you spend on a target the better the result. As for colour, it's working for me!

Now... Is it me or is the image a bit soft? It looks like it has a shallow depth of field, to use a term from 'normal' photography. Is that the way this target is? The stars too, while good and round don't look as tight as I would have expected. I am far from experienced enough to know if these comments are valid, but I thought that I would speak my mind. Either it will help you, Sara, or I will learn something!!! This is why I asked you about collimation somewhere in another thread, I just wonder if it is spot on? I look forward to your's and other's opinions on this.

Out of interest - what's your next target going to be?!

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Lovely deep detail, the time at the scope has paid off.

One thing that you could take a look at is the transition between the sharpening of the detail in the core in relation to the smoothing of the faint outer arms, the difference between the too areas looks a bit extream IMHO .

Hope that makes sense.

A great shot, spurs me on to add more time to my data.

Mike

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Very Nice work Sara! :)

Now... Is it me or is the image a bit soft? It looks like it has a shallow depth of field, to use a term from 'normal' photography. Is that the way this target is?

I think it's inherent to these Sony sensors. As the Atik 460ex is high on my list of possible CCD camera to buy, I have browsed through lots of images taken with the 460ex so far and have been a bit dissapointed with the Depth in all of them.

These sony sensors seem to produce a very flat (2D like) image compared to images taken with for example Kodak sensors, like the KAF8300 and KAI 04022, which show more Depth (3D like).

So I don't think it has anything to do With Sara's Processing skills, which I can only hope (dream) to match one day. :rolleyes:

Edited by GuillermoBarrancos

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How did the 3nm Ha work out?

Judging from the red shift of a couple of galaxies I looked at I decided I wouldn't even try such a narrow pass band on galaxies as it reduced the transmission to around 50% or less.

The 3nm Ha added mad mad amounts of Ha in the centre and certainly did add to the galaxy arms.

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Now... Is it me or is the image a bit soft? It looks like it has a shallow depth of field, to use a term from 'normal' photography. Is that the way this target is? The stars too, while good and round don't look as tight as I would have expected. I am far from experienced enough to know if these comments are valid, but I thought that I would speak my mind. Either it will help you, Sara, or I will learn something!!! This is why I asked you about collimation somewhere in another thread, I just wonder if it is spot on? I look forward to your's and other's opinions on this.

Out of interest - what's your next target going to be?!

Cheers Gave - Regarding it being a little soft, I do agree, but based on my experience with the C9.25 so far, it just seems to be something a little inherent with this type of scope. I certainly can't get the razor sharp images that my refractor churns out. However I am more than happy to be corrected if this isn't the case, but it's just what I'm seeing as the difference.

Next target? ............. I have no idea!

One thing that you could take a look at is the transition between the sharpening of the detail in the core in relation to the smoothing of the faint outer arms, the difference between the too areas looks a bit extream IMHO .

Cheers Mike - I see what you mean now! I'd like to say I'll go back and relook at it, but this thing robbed me of almost 2 days of my life, so I rarely go back!! Something that I will definitely bear in mind though next time! I guess the detail would have come from the luminance, but that looked fine when posted.

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I think it's inherent to these Sony sensors. As the Atik 460ex is high on my list of possible CCD camera to buy, I have browsed through lots of images taken with the 460ex so far and have been a bit dissapointed with the Depth in all of them.

These sony sensors seem to produce a very flat (2D like) image compared to images taken with for example Kodak sensors, like the KAF8300 and KAI 04022, which show more Depth (3D like).

An interesting thought, and something that I've never noticed in this Sony chip before. It's more than likely my processing to be honest!

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I think the depth issue might well be from the Sony sensor, which is big on sensitivity, on the other hand. Very hard to say.

I like the image very much. I can see what Mike is talking about and the relationship between sharpening and smoothing is one area that might let it give a bit more. Personally I prefer the colour select tool in Ps for selecting my areas for smoothing. Sara knows my addiction to Layers and the eraser!!

The Ha is very interesting. Maybe the extremely hard transition comes from the use of the 3Nm. The whole point of this filter is to give strong contrasts. Maybe slightly softer contrasts would be better on galaxies but, then again, there are things I haven't seen before going on right in the core here. Pretty exciting.

Looking carefully at the stars we see something resembling coma affecting the blue channel. Go round the bright stars on the image and you see the blue spilling out a little on one side, but the side on which it spills out varies with the position on the chip. It's consistent with a little coma and (not sure) collimation. Reflector gurus, anywhere? It's hardly disastrous and could be processed out quite easily, though not in the most ethical of ways. Personally I wouldn't let that stop me! Heh heh.

Great stuff, Sara, an ambitious project pulled off strongly.

Olly

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Sara I notice the stars have off center cores any ideas on this?

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Thanks Olly and Earl - Much to think about and keep my eye on for the next target!

@Olly - I will be checking collimation next week as I break down the imaging train, if it's OK then I suppose that the issue will point to coma. What can I expect with an £800 scope? I really need to be a little realistic, I'm hardly going to be able to compete with the big boys am I :grin:

@Earl - I have no idea, perhaps the result of the coma / collimation that Olly mentions.

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Sara, I look forward to hearing what you find with the collimation. I'm hoping that it is that simple and that a tweak will improve sharpness further. I was stunned by the improvement I found in my C8 once it was properly collimated (or at least what I could manage as 'properly'!).

Please don't let this discussion detract from the superb image that you have made here. I only mentioned the point as I know that you will be striving for perfection...

My gut feel is that it isn't to do with the chip. You have more than proved that it is well capable of absolutely stunning images that are crystal clear and pin sharp. As for your processing - that is one thing that is certainly not at fault. Your images generally define the way the target should be processed!

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M63 is one of a few Galaxies that show an abnormal amount of crisp and clear centre and rather blurry looking outer regions. The fact that this image shows it in a very pronounced way isn't  that far from reality. The outer halo goes on for quite a bit and part of it is showing in the far right " Blob ". There are other images produced from much larger scopes that show the same effect, even the Subaru ! In an image by R Jay GaBany it looks to be the tidal outer regions that are causing the blur.

My personal opinion on the blue around the stars is that it looks like the whole image has shifted in focal length when focused. I just can't see that effect being caused by collimation. I could very well be wrong :eek:

Registar or PI used on each individual channel and realigned may work.

I like it,

Dave.

Edit. Sara may tell me that she didn't have to re focus between the Red and Blue. That'll make a mess of my theory :)

Edited by davew

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Further edit .... I just downloaded the image and tried Registar on it. Didn't work correctly.

Blows out my idea then.

Dave.

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No probs Gav about what you mention - I am always willing to listen to opinions about my images and how I get there, positive or negative. People have helped me immensely over the last three years and it hasn't been through sugar coated comments. I like to hear it warts and all, then I can look at it again! :grin:

Thanks Gordon for your comments :smiley:

@Dave - I did refocus between blue and red as they were taken on different nights! - I appreciate your thoughts on it - More investigations needed :grin:

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Great stuff, Sara!

The slight softness in the stars that you mentioned : I got this when imaging with a (Meade) SCT in the past and assumed it was just a characteristic of SCT images.  To be fair, though, we shouldn't compare to star images taken with a refractor at much shorter focal length.  At this image scale the star PSF is spread out over many more pixels and any (inherent) fuzziness at the edges will be easier to see.

I too noticed the cyan fringes at the edges of the bright stars.  Looking at the individual colour channels, the bright stars that are affected are sharper and rounder in the red channel than they appear in the blue and green channels.  But not all the stars - weird! If it was coma though, I would expect it to have affected all three colour channels roughly equally. if you collected the R, G and B on different nights and simply got slightly better conditions on the 'red' night, and less favourable for blue and green, I suppose you might get some asymmetric fuzziness in the halos around bright stars.  Might be interesting to look at the RGB-only image before Lum-combine and blink back and forth between the separate colour channels.

Adrian

Edited by opticalpath

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Many thanks for this Adrian - I did collect the green and blue on the same night, so the conditions for both of those would have been the same.

More images needed!!! :smiley:

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Well, you are not alone. Although your results are way ahead of the paltry attempts with mine.

All I can say is take your time & whatever you do make very small tweeks & re test. I really hope ¨tinkering¨ doesn't make it any worse for you Sara, as it's done for me...  :eek:  (As you know from my SCT collimation thread)

The comments on here are the same observations I made on mine. I started tweeking because it looked ¨soft¨ & having splashed out on a set of Bobs Knobs and a Hotech Advanced CT laser I've had several attempts at aligning the whole imaging train but I'm still trying to get back to as good an imaging result as before I started. It may look ok visually but when imaging the stars are not right at all. Even with the Hotech (which is good) there's only so much that can be done without spending valuable time under real stars checking. Which I just haven't had enough of. It's quite a different learning curve to fracs, though I'm determined not to be beaten.

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not sure if its my eyes but it looks to have a weird DOF, kind of OOF to the edge and very crisp in the middle?

loving the image tho, cant wait to see more from the C9.25

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Further edit .... I just downloaded the image and tried Registar on it. Didn't work correctly.

Blows out my idea then.

Dave.

I was about to try that myself when some new guests arrived and I had to do some work! I think that the shapes of the red stars will meke it difficult for any software to calculate a logical centroid so this won't be helping.

But let's not let all this detract from what is a ruddy marvellous image at a seriously difficult focal length and with an essentially budget scope. Look at those core details. Cor!

Olly

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Absolutely Olly! I challenge anyone to better it!!!!

As for doing some work... You call that work?! Chatting with nice people and looking at the stars...?!!!?

Sent from my iPhone using Tapatalk

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