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Should I see nebulosity in my images?


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A few days ago I posted about my struggle finding deep space targets. So even after continuing to try and find them, I have still run into trouble. So I have been trying to image easier objects. One of those is the North American Nebula. I figured it would be pretty easy to spot some sort of the nebulosity but was mistaken. I was able to spot Deneb in my photo but couldn't see any sort of nebula. 

I really don't know if the issue is my exposure time, bright skies, or me just not finding the target I am begging to find. The exposure I took was around 20 seconds(I am in boatel class 7) and the image had an orangish-tinted background meaning that if my exposure were longer, I would start getting white-tinted skies. So would it just be an issue with my exposure time and having to bring out the image during stacking or would it be likely that I am completely missing the target.

Thanks for the help in advance!

My gear consists of:

WO Zenithstar 61

Canon T2i

Star Adventurer Pro Pack 2i

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You will not see any nebulosity with an exposure of 20 seconds even if your camera is modified. When I took images of the NAN I saw the nebulosity and was usinmg a modified Canon and the subs were 400 seconds. I think that you probably don't need quite such long subs as that but I suggest that you would need 200 seconds at least with a modified camera. The other way is to take many images (hundreds) at shortish exposures and stack them (lucky imaging).

People do image from Bortle 7 areas but often try Ha filters which involves even longer exposures.

 

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2 hours ago, PeterCPC said:

You will not see any nebulosity with an exposure of 20 seconds even if your camera is modified. When I took images of the NAN I saw the nebulosity and was usinmg a modified Canon and the subs were 400 seconds. I think that you probably don't need quite such long subs as that but I suggest that you would need 200 seconds at least with a modified camera. The other way is to take many images (hundreds) at shortish exposures and stack them (lucky imaging).

People do image from Bortle 7 areas but often try Ha filters which involves even longer exposures.

 

I don't sort of agree with this. I have bortle 8 skies. My canon is modified. When framing the target I can see the nebula when doing a test 20 second exposure.  So it could be other issues with the OP not seeing any nebulosity.

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3 hours ago, Scribblecrans said:

A few days ago I posted about my struggle finding deep space targets. So even after continuing to try and find them, I have still run into trouble. So I have been trying to image easier objects. One of those is the North American Nebula. I figured it would be pretty easy to spot some sort of the nebulosity but was mistaken. I was able to spot Deneb in my photo but couldn't see any sort of nebula. 

I really don't know if the issue is my exposure time, bright skies, or me just not finding the target I am begging to find. The exposure I took was around 20 seconds(I am in boatel class 7) and the image had an orangish-tinted background meaning that if my exposure were longer, I would start getting white-tinted skies. So would it just be an issue with my exposure time and having to bring out the image during stacking or would it be likely that I am completely missing the target.

Thanks for the help in advance!

My gear consists of:

WO Zenithstar 61

Canon T2i

Star Adventurer Pro Pack 2i

When doing your test images what iso are you using?

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25 minutes ago, Chefgage said:

I don't sort of agree with this. I have bortle 8 skies. My canon is modified. When framing the target I can see the nebula when doing a test 20 second exposure.  So it could be other issues with the OP not seeing any nebulosity.

"My canon is modified" - quite.

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Some things to clarify:

1) You will need to stretch the image to see fainter nebulosity. Are you familiar with stretching linear data? Some software will give you an automatic 'preview stretch' but usually you have to initiate a stretch yourself. If you capture into a PC you can use your capture software to do this. In their original linear form most astro-images look like stars on a very black background with little else showing.

2) You'll need to remove the LP gradient or orange washout. With modern software this is remarkably easy. Pixinsight's Dynamic Background Extraction lets you tell the software what should be neutral background sky (dark grey) in your capture and then, when applied, the algorithm re-balances the colour and lets the underlying details emerge. Alternatives to Pixinsight include Gradient Xterminator (Photoshop plug-in), Astro Pixel Processor, Astro-Art, Startools and more. You'll need a post processing software anyway so be sure to choose one with a good gradient remover.

Olly

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Posted (edited)

Hey there,

With a T2I and a ZS61, and me assuming that a T2i is a crop sensor, if you see deneb in your exposure, its a good chance you have missed the NA nebula anyway (Tordapending on rotation), this is just from my experience of a crop sensor eos 800d and ZS61. To frame up your ZS61 to NA Nebula, I'm not sure on the exact vocabulary to use so Ill try and explain it as best as I can. But in Cygnus's current position in the early night sky, Deneb is above Xi Cygni (Which it should be if I am assuming right, with you being in the Northern Hemisphere), You should frame XI Cygni right at the bottom of your shot, this way you will have all of the NA nebula in your shot, but you will not see Deneb.

Here is also an example of a single shot on my unmodified 800D, 90 seconds exposure in a bortle 5 sky, compared to 1 hours data (If I remember right), stretched A LOT. As you see, if you didnt know NA nebula was there in the single shot, you probably wouldnt see it at all.

The final image is cropped, the single exposure is uncropped, as you can see both Deneb and XI Cygni is visible, but this is because Im using a Samyang 135mm at the time, not my ZS61. I just put these there to show you even in a 90 second exposure NA Neb is basically invisible compared to the finished product. So when framing objects like this, you've got to look for the positions of the brighter stars and compare to other finished photos of the NA neb, kind of like old fashioned manual platesolving 😅.

Hope this helps,

Grant

NAsecondattempt3rdedit.png

90sNAneb.png

Edited by Grant93
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5 hours ago, Chefgage said:

When doing your test images what iso are you using?

I was using ISO 800 because 1600 is a little harsh on my images. The recommendation is 1600 though. Should I bump it up?

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Posted (edited)
3 hours ago, Grant93 said:

 

The final image is cropped, the single exposure is uncropped, as you can see both Deneb and XI Cygni is visible, but this is because Im using a Samyang 135mm at the time, not my ZS61. I just put these there to show you even in a 90 second exposure NA Neb is basically invisible compared to the finished product. So when framing objects like this, you've got to look for the positions of the brighter stars and compare to other finished photos of the NA neb, kind of like old fashioned manual platesolving 😅.

 

 

90sNAneb.png

I can't believe this. I had it in my frame and I thought it was just stars so I passed by the shot... I remember literally looking at the camera screen and seeing that heart shaped start outline at the bottom.  Well I guess back to imaging...

Thanks a lot though!

Edit:90sNAneb.thumb.png.0d749d6cdf8e2401eed86580bac3c2c2.png.722cc9933155a9d54e73cf7185ae062c.png

Edited by Scribblecrans
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11 minutes ago, Scribblecrans said:

I can't believe this. I had it in my frame and I thought it was just stars so I passed by the shot... I remember literally looking at the camera screen and seeing that heart shaped start outline at the bottom.  Well I guess back to imaging...

Thanks a lot though!

Edit:90sNAneb.thumb.png.0d749d6cdf8e2401eed86580bac3c2c2.png.722cc9933155a9d54e73cf7185ae062c.png

Haha no problem :D A lot of trials and errors for us new comers in astrophotography :D

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I should be happy that i passed this kind of level with imaging, and i am even happier and lucky that i started with a mono cooled camera, but the bad and sad news that since i started in 2017 i didn't focus much on DSO and couldn't make much successful images, only recently i put my knowledge and experience towards it, but i still feel sad i wasted all those years, so i hope by now and later that i make much more results great enough so those years aren't wasted.

I did my last target of Pelican nebula, in SHO, happy so far, so i think i should be proud that i have equipment that helping me to do it, not sure if i will give that NA nebula a try one day, but hopefully i can get scopes or optics to capture both nebulae at once.

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