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I really hope this dark sky trip isn't for nothing.


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Hi everyone,

After lockdown we decided to go to a proper dark sky place and image, of course, the orion constellation.

So we finally arrived to a Bortle 3 sky, maybe even 2. There was a thin layer of clouds, albeit not enough to stop us from imaging hehe.

Equipement used was a stock canon 550D, a sky watcher star adventurer, kit 18-55mm lens, cheap tripod, NINA and well, thats it.

Unfortunately, both of my batteries died quickly, so I couldn't take ANY calibration frames, although, I do have some dark frames from other days, as well ass some bias. Total stack is about an hour and 15 minutes, having to bin a few due to heavy clouds or tracking error. 

Problem is that, although my hopes weren't too high, I thought it would turn out better. I am processing with star tools (previously stacked in dss) and can't get to show nor the horsehead nebula nor Barnard's loop (I know it's a tricky one with a stock dslr, but thought with an hour and a half of integration time and such dark skies I would be able to see a bit more of it.

I guess it's due to the fact that I'm very new into post-processing, or I suck at imaging too haha.

Anyways, I'm leaving the stacked tiff file here, for anyone to try and convince me that we didn't just drive 2 hours for nothing 😕 

https://drive.google.com/file/d/1Bh4V_1fhvWJwPwy2Ip_87-iFOAh-qtYs/view?usp=sharing

Thanks for reading and clear skies!

Edited by feverdreamer1
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7 hours ago, jager945 said:

Hi,

The dataset appears to be of M31, not the Orion constellation?

 

 

7 hours ago, JemC said:

That tiff file is M31, 

Hi,

I linked the wrong file, sorry, correct file is now linked at top. And another thing I noticed is that the stack that DSS produced is quite bright (I can clearly see the main stars in orion, as well as m42), is that to be expected? I normally always have quite dark stacks,  but this is my first time imaging from a proper dark sky, so who knows

Edited by feverdreamer1
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Hi,

I've worked through the raw files using Pixinsight's Dynamic Background Extraction and then an assortment of techniques in Photoshop. I'm afraid that your camera really is blocking Ha to a remarkable degree and there is very little signal from it in the data. I have one trick which is particularly good at extracting Ha but even that found almost no sign of Barnard's loop. If you want to image emission nebulae you're going to need either a camera mod or a different camera.

1713709942_OrionOllyPprocessing.thumb.jpg.391d56f402190cf9754a83101a620e42.jpg

 

There is another issue: your stars are showing a well-known aberration which makes them look like shuttlecocks. This is resampled upwards for clarity.

 

shuttlecocks.jpg.2506061afeb8c7a8336e892ec1674576.jpg

In my view this is not a tracking issue because the stars fan out wards and upwards, they don't trail into parallel sided streaks. We see this quite often and it arises from miscollimated optics. In daytime images the lens may seem fine because stars are very exacting tests for any optics. The effect might be mitigated by tighter focus but my guess is that it won't go away entirely.

There is a Photoshop 'dodgy bodge' for oval stars but it did more harm than good in this case. It does work on trailed stars which confirms that these are not trailed but optically distorted.

So much for the bad news. The good news is that you do, after all, have your picture of the constellation and, if kept in a smaller format, the stars look OK. Your tracking also seems up to the task. The image was easy to flatten and had little residual gradient, meaning a good background sky is possible from your location. These are important positives to take away from your trip. I think you've come close to what is possible with a camera and lens less than ideally suited to this task. 

Olly

Edited by ollypenrice
typo
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6 hours ago, ollypenrice said:

Hi,

I've worked through the raw files using Pixinsight's Dynamic Background Extraction and then an assortment of techniques in Photoshop. I'm afraid that your camera really is blocking Ha to a remarkable degree and there is very little signal from it in the data. I have one trick which is particularly good at extracting Ha but even that found almost no sign of Barnard's loop. If you want to image emission nebulae you're going to need either a camera mod or a different camera.

1713709942_OrionOllyPprocessing.thumb.jpg.391d56f402190cf9754a83101a620e42.jpg

 

There is another issue: your stars are showing a well-known aberration which makes them look like shuttlecocks. This is resampled upwards for clarity.

 

shuttlecocks.jpg.2506061afeb8c7a8336e892ec1674576.jpg

In my view this is not a tracking issue because the stars fan out wards and upwards, they don't trail into parallel sided streaks. We see this quite often and it arises from miscollimated optics. In daytime images the lens may seem fine because stars are very exacting tests for any optics. The effect might be mitigated by tighter focus but my guess is that it won't go away entirely.

There is a Photoshop 'dodgy bodge' for oval stars but it did more harm than good in this case. It does work on trailed stars which confirms that these are not trailed but optically distorted.

So much for the bad news. The good news is that you do, after all, have your picture of the constellation and, if kept in a smaller format, the stars look OK. Your tracking also seems up to the task. The image was easy to flatten and had little residual gradient, meaning a good background sky is possible from your location. These are important positives to take away from your trip. I think you've come close to what is possible with a camera and lens less than ideally suited to this task. 

Olly

Hi Olly

First of all thank you for taking the time to process and to tinker with the file. Much appreciated. 

I also thought that my camera and lens wouldn't be perfect and well, I just decided to go with it. 

Its quite saddening that my dslr is blocking so much Ha. But I wanted to ask you why in this landscape shot there is more "red". I dont know if it's me but I can kind of see Barnard's loop. The image has been put through editing, I can also attach the raw camera-from file.

So I guess i dont have anything to do, because I'm guessing that i couldnt have done anything better? (Besides polar aligning and maybe checking focus). 

And if I were to upgrade my equipment, should I go after a new camera or a new lens? (The latter one is far cheaper and I wouldn't mind spending a bit more and getting a good lens, like the nifty fifty). 

Thank you very much, and clear skies!

S

IMG_20201220_205219_313.jpg

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It's a pleasure.

There is an arc of increased stellar density on the left of your image, annotated here:

985375552_notbarnard2.jpg.7eaff8494efa8c2d673909127de7ae9c.jpg

Although it's interesting (and I have never seen it before) this isn't Barnard's loop. To help you decide whether or not you're seeing the Loop in your image I've superimposed a camera lens image in HaRGB over yours to show exactly where it is...  (This was a six panel HaRGB CCD image with 80 hours of exposure so don't beat yourself up.)

599175812_Notbarnard3.jpg.05fc0940dce32b29d44a0685ec3782d3.jpg

Olly

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Surely the increased stellar density from the top centre to left centre of the image is non other than the Milky Way, whereas the lower part of the 'arc' appears to be light pollution.

Edited by Seelive
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13 hours ago, ollypenrice said:

It's a pleasure.

There is an arc of increased stellar density on the left of your image, annotated here:

985375552_notbarnard2.jpg.7eaff8494efa8c2d673909127de7ae9c.jpg

Although it's interesting (and I have never seen it before) this isn't Barnard's loop. To help you decide whether or not you're seeing the Loop in your image I've superimposed a camera lens image in HaRGB over yours to show exactly where it is...  (This was a six panel HaRGB CCD image with 80 hours of exposure so don't beat yourself up.)

599175812_Notbarnard3.jpg.05fc0940dce32b29d44a0685ec3782d3.jpg

Olly

Hi,

Yes, I didn't mean that stellar "cloud", I meant what appears to be Barnard's Loop in your image, but I think it's just me overthinking it and 'seeing' what isn't really there haha.

That image though, the one you've superimosed... breathtaking. Really. I was kinda hoping for something like that (not exactly like that obviously). I mean that I was hoping to at least get 'some' red. Now I just feel like an idiot for driving 2 hours and sitting in the cold for just a few landscape shots :/. 

So what do you think is the problem? Is it the camera or the lens? I have seen some lenses on a second hand website, and I'm mainly looking for an EF or a manual lens, so it fits my svbony uhc filter. Do you reckon I could image the same orion constellation from a bortle 8, a nifty fifty, and a svbony filter? Integration time isn't a problem at all.

Thank you very much Olly,

S

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12 hours ago, Seelive said:

Surely the increased stellar density from the top centre to left centre of the image is non other than the Milky Way, whereas the lower part of the 'arc' appears to be light pollution.

Yes! there was actually a village behind the mountain, but I believe the 'arc' is actually just clouds, as they can be seen to on the right of the image.

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10 minutes ago, feverdreamer1 said:

Hi,

Yes, I didn't mean that stellar "cloud", I meant what appears to be Barnard's Loop in your image, but I think it's just me overthinking it and 'seeing' what isn't really there haha.

That image though, the one you've superimosed... breathtaking. Really. I was kinda hoping for something like that (not exactly like that obviously). I mean that I was hoping to at least get 'some' red. Now I just feel like an idiot for driving 2 hours and sitting in the cold for just a few landscape shots :/. 

So what do you think is the problem? Is it the camera or the lens? I have seen some lenses on a second hand website, and I'm mainly looking for an EF or a manual lens, so it fits my svbony uhc filter. Do you reckon I could image the same orion constellation from a bortle 8, a nifty fifty, and a svbony filter? Integration time isn't a problem at all.

Thank you very much Olly,

S

You'd have picked up the Ha if the camera were capable of doing it. I'm pretty sure of that. Looking up the 550 I see that it is between 10 and 8 years old. At that time the filters used on DSLRs to exclude light either side of the visible spectrum excluded the Ha emission line far more severely than they do now. That's why a whole industry of camera-modding grew up. One of our guests tried the North America Nebula with an unmodded camera and we could extract almost nothing from the stack. By the following year he'd modded the camera and the NAN stood old boldly. So I think your camera's in-built filter is the culprit.

The shuttlecock stars are almost certainly from the lens but further experimenting just from your home site would confirm or deny this. How do you focus? I'm not a DSLR imager but I've read that one way is to aim into some starry sky, zoom right in, and look at the very faintest stars on screen. Only when focus is bang on will they be visible. The slightest displacement either side will make them disappear.

The Nifty Fifty has a proven record. This is by Stéphane Guisard and Rob Gendler. (So quite serious!!!😁)

http://sguisard.astrosurf.com/Pagim/Orion_constellation-HRVB-50mm.html

Olly

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28 minutes ago, ollypenrice said:

You'd have picked up the Ha if the camera were capable of doing it. I'm pretty sure of that. Looking up the 550 I see that it is between 10 and 8 years old. At that time the filters used on DSLRs to exclude light either side of the visible spectrum excluded the Ha emission line far more severely than they do now. That's why a whole industry of camera-modding grew up. One of our guests tried the North America Nebula with an unmodded camera and we could extract almost nothing from the stack. By the following year he'd modded the camera and the NAN stood old boldly. So I think your camera's in-built filter is the culprit.

The shuttlecock stars are almost certainly from the lens but further experimenting just from your home site would confirm or deny this. How do you focus? I'm not a DSLR imager but I've read that one way is to aim into some starry sky, zoom right in, and look at the very faintest stars on screen. Only when focus is bang on will they be visible. The slightest displacement either side will make them disappear.

The Nifty Fifty has a proven record. This is by Stéphane Guisard and Rob Gendler. (So quite serious!!!😁)

http://sguisard.astrosurf.com/Pagim/Orion_constellation-HRVB-50mm.html

Olly

So I guess I should look into getting my camera modified. Or well, till then I can image galaxies and other stuff, as they don't 'peak' in Ha. 

Regarding the focus, I normally just point to the brightest star and make it look the smallest I can at 10x zoom on the LCD. Still, I am printing a Bahtinov mask that will help me achieve that perfect focus hahaha.

Damn, all those images make me feel even worse for wasting such a trip 😆. At least I learnt a bunch of things. 

Will look into the Nifty Fifty, but, do you think it would be an error to get 50mm lenses from other 'white' brands? They are far cheaper, but I'm afraid of getting what I pay for.

Clear skies,

S

 

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13 minutes ago, feverdreamer1 said:

So I guess I should look into getting my camera modified. Or well, till then I can image galaxies and other stuff, as they don't 'peak' in Ha. 

Regarding the focus, I normally just point to the brightest star and make it look the smallest I can at 10x zoom on the LCD. Still, I am printing a Bahtinov mask that will help me achieve that perfect focus hahaha.

Damn, all those images make me feel even worse for wasting such a trip 😆. At least I learnt a bunch of things. 

Will look into the Nifty Fifty, but, do you think it would be an error to get 50mm lenses from other 'white' brands? They are far cheaper, but I'm afraid of getting what I pay for.

Clear skies,

S

 

'Damn, all those images make me feel even worse for wasting such a trip 😆. At least I learnt a bunch of things. '  That's a contradiction in terms! You learned a lot. There will always be an element of,  'Two steps forward, one step back,' in this game.

I know little about camera lenses, I'm afraid, but the Samyangs have a big following. My lens Orion was with the Samyang 85. (6 panel mosaic on a small CCD chip with some bits enhanced by telescopic data.)

1803256554_ORIONSamyang85JPEG.thumb.jpg.8d28379d13505753be7e51c3afd8ad62.jpg

A B mask ought to help. Telescope Service also do a crafty gadget to help with fine focus. I used to use this at the time.

i-4TCd6Px-M.jpg

Olly

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I had a go at your image, and maybe, just maybe, there is a hint of Barnard's loop.

There is a very faint red arc left of the flame nebula. But the data is too weak, and as Olly already wrote, to bring out emission nebulas, you need a modded camera.

Nevertheless, this is a very nice image. You can try improving the star shapes by stopping down the lens. This will create star spikes, but should give a somewhat better image quality.

Right of Rigel, there is a very faint Witch Head nebula, just visible in your image (at least in the processed image on my screen). To bring out this faint signal, you need more integration time, and meticulous calibration, especially flats. If you take flats at a later time, this will risk leaving dust bunnies, but that doesn't seem to be a problem here. Flats will help with the vignetting. And if you guide, dither. Move the camera slightly between exposures, some 12 - 15 pixels at least, in a random direction or spiraling pattern.

Stretching also brought out narrow horizontal lines (vertical in the rotated image), that could not be removed by Canon Banding Reduction. This could be bad pixel rows, so you might want to examine the single subs. If they are in all your images, you might consider investing in a new camera.

1364210683_TheOrionConstellation.thumb.jpg.d4ff806dbc2905a59cd1512cea604d1c.jpg

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On 22/12/2020 at 10:28, ollypenrice said:

'Damn, all those images make me feel even worse for wasting such a trip 😆. At least I learnt a bunch of things. '  That's a contradiction in terms! You learned a lot. There will always be an element of,  'Two steps forward, one step back,' in this game.

Haha, yes, I hope. But it seems like I've been taking one step forward, and three steps backwards 😕 .

On 22/12/2020 at 10:28, ollypenrice said:

I know little about camera lenses, I'm afraid, but the Samyangs have a big following. My lens Orion was with the Samyang 85. (6 panel mosaic on a small CCD chip with some bits enhanced by telescopic data.)

1803256554_ORIONSamyang85JPEG.thumb.jpg.8d28379d13505753be7e51c3afd8ad62.jpg

A B mask ought to help. Telescope Service also do a crafty gadget to help with fine focus. I used to use this at the time.

i-4TCd6Px-M.jpg

Olly

I have been looking at some rokinon/samyang lenses, but I'm thinking of getting a proper scope, something like the existing 72 ED. Just wondering if It'll fit the clip in filter 🤔

And I will definitely check focus every 5-10 frames, just to be sure.

Thanks Olly,

S

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13 hours ago, wimvb said:

I had a go at your image, and maybe, just maybe, there is a hint of Barnard's loop.

There is a very faint red arc left of the flame nebula. But the data is too weak, and as Olly already wrote, to bring out emission nebulas, you need a modded camera.

Nevertheless, this is a very nice image. You can try improving the star shapes by stopping down the lens. This will create star spikes, but should give a somewhat better image quality.

Right of Rigel, there is a very faint Witch Head nebula, just visible in your image (at least in the processed image on my screen). To bring out this faint signal, you need more integration time, and meticulous calibration, especially flats. If you take flats at a later time, this will risk leaving dust bunnies, but that doesn't seem to be a problem here. Flats will help with the vignetting. And if you guide, dither. Move the camera slightly between exposures, some 12 - 15 pixels at least, in a random direction or spiraling pattern.

Stretching also brought out narrow horizontal lines (vertical in the rotated image), that could not be removed by Canon Banding Reduction. This could be bad pixel rows, so you might want to examine the single subs. If they are in all your images, you might consider investing in a new camera.

1364210683_TheOrionConstellation.thumb.jpg.d4ff806dbc2905a59cd1512cea604d1c.jpg

Right? I knew I was seeing at least something red 🤣😅.

Yeah, I guess I'll eventually need to change my camera, like Olly said, its 9 years old. But for right now I'm thinking of getting a better lens, I.e a proper telescope.

Yeah, I can see something of the Witch Head nebula, as well as the Horsehead and flame nebula. 

How have you processed the image? I really like it. Did you follow any guide or was it just tinkering around?

Also, that software you mention, Canon Banding Reduction, is it a PS plug in? If so, where can I find it?

Thank you very much and clear skies,

S

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19 minutes ago, feverdreamer1 said:

How have you processed the image? I really like it. Did you follow any guide or was it just tinkering around?

Also, that software you mention, Canon Banding Reduction, is it a PS plug in? If so, where can I find it?

I use PixInsight. Don’t know if PS has a plug in that removes banding.

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