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Astrophotography and Sketching >> Beginning and Intermediate Imaging

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BenB85
member
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Reged: 02/17/13

Loc: Colorado and Alaska USA
Whats wrong with my first photo? 5x90sec Orion new
      #5708030 - 03/02/13 12:35 AM Attachment (45 downloads)

Hello, I just received my scope and mount today, 127mm apo. So I tried astrophotography.

This is my first astrophoto ever. Its is a composite of 5 90 second exposures through my 5" apo. Is cold here in Denver so I set up the scope on my balcony. I cant see north from my balcony so I just pointed the mount in general north. I did use the SSAG.

Does this look like a 7.5 minute exposure to you guys? I guess Im a little disappointed. Granted the light pollution is bad, but I was expecting more light/detail with 7 minutes.

Im considering returning it and getting a Celestron Edge 1100HD on the CGEM DX with a hyperstar.

I used Deep Sky Stacker and Adobe CS5.

Any advice is appreciated!
Thanks

Edited by BenB85 (03/02/13 04:35 AM)


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NeilMac
Carpal Tunnel


Reged: 09/25/10

Loc: MedHat, AB, Canada
Re: Whats wrong with my first photo? new [Re: BenB85]
      #5708041 - 03/02/13 12:45 AM

Besides looking a bit out of focus, you may just need to adjust the colors, reduce yellow saturation etc.
Nice other wise. Play with the picture a bit to see what you can get.


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Patrick
Postmaster
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Reged: 05/16/03

Loc: Franklin, Ohio
Re: Whats wrong with my first photo? new [Re: BenB85]
      #5708042 - 03/02/13 12:46 AM

You probably picked one of the harder objects to image as your first object. It's very easy to blow out the core of m42, yet the object has a very high dynamic range. In light polluted skies, you'll want to use a light pollution filter, and then use a Minimal Exposure Regime as explained in the link. Using your histogram is the key to getting your DSLR exposures correct.

Patrick


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Joe Bergeron
Vendor - Space Art


Reged: 11/10/03

Loc: Upstate NY
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: BenB85]
      #5708080 - 03/02/13 01:20 AM

You're considering returning your scope on the basis of a single imperfect photo made under imperfect conditions and with no experience? Have a little more patience. Experiment, and learn what you're doing wrong. Buying a new scope won't help with that.

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BenB85
member
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Reged: 02/17/13

Loc: Colorado and Alaska USA
Re: Whats wrong with my first photo? new [Re: Patrick]
      #5708083 - 03/02/13 01:28 AM

Quote:

You probably picked one of the harder objects to image as your first object. It's very easy to blow out the core of m42, yet the object has a very high dynamic range. In light polluted skies, you'll want to use a light pollution filter, and then use a Minimal Exposure Regime as explained in the link. Using your histogram is the key to getting your DSLR exposures correct.

Patrick




Is the light pollution the main issue with the photo then? Meaning, a 7.5 minute photo in dark skies would be far superior?

Thanks


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Patrick
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Reged: 05/16/03

Loc: Franklin, Ohio
Re: Whats wrong with my first photo? [Re: BenB85]
      #5708107 - 03/02/13 02:06 AM

Quote:

Is the light pollution the main issue with the photo then?




No, you've over exposed the core of M42. That's detail you'll never get back since it's all white. M42 is a difficult object to get right because it has very bright regions and then a lot of faint wispy regions. To get it right you really need to expose for the core and also expose for the faint areas and then combine them.

If I were you I'd pick an easier object to start with.

Secondly, you need to be taking a lot more subframes. Several hours worth would be more like what you need. You need lots of subframes so that you can start to get rid of the noise a camera produces. Did you take darks, flats, and bias frames as well? You need those other frames to subtract out the noise and camera artifacts to get to the real image.

Get the book A Beginners Guide to DSLR Astrophotography and read it.

Patrick


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BenB85
member
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Reged: 02/17/13

Loc: Colorado and Alaska USA
Re: Whats wrong with my first photo? new [Re: Patrick]
      #5708127 - 03/02/13 02:38 AM

Quote:

Quote:

Is the light pollution the main issue with the photo then?




No, you've over exposed the core of M42. That's detail you'll never get back since it's all white. M42 is a difficult object to get right because it has very bright regions and then a lot of faint wispy regions. To get it right you really need to expose for the core and also expose for the faint areas and then combine them.

If I were you I'd pick an easier object to start with.

Secondly, you need to be taking a lot more subframes. Several hours worth would be more like what you need. You need lots of subframes so that you can start to get rid of the noise a camera produces. Did you take darks, flats, and bias frames as well? You need those other frames to subtract out the noise and camera artifacts to get to the real image.

Get the book A Beginners Guide to DSLR Astrophotography and read it.

Patrick




I will get that book. Thank you Patrick.

This is why I am concerned: http://www.cloudynights.com/documents/rebel.pdf

This gentleman has a 60mm f5.8 scope, unmodified DLSR totaling 8 minutes and he has a fantastic amount of detail coming through. A 5" APO with 7.5 minutes total, modified DLSR, should blow that away. So I dont understand why there is not more light coming through, even if the core is burned out, I should still be getting more nebulosity.

Ben


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BenB85
member
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Reged: 02/17/13

Loc: Colorado and Alaska USA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: BenB85]
      #5708158 - 03/02/13 03:46 AM Attachment (21 downloads)

Quote:

Hello

This is my first astrophoto ever. Its is a composite of 5 90 second exposures through my 5" apo. Is cold here in Denver so I set up the scope on my balcony. I cant see north from my balcony so I just pointed the mount in general north. I did use the SSAG.

Does this look like a 7.5 minute exposure to you guys? I guess Im a little disappointed. Granted the light pollution is bad, but I was expecting more light/detail with 7 minutes.

Im considering returning it and getting a Celestron Edge 1100HD on the CGEM DX with a hyperstar.

I used Deep Sky Stacker and Adobe CS5.

Any advice is appreciated!
Thanks




Here is the same set just photoshopped more.

Edited by BenB85 (03/02/13 03:47 AM)


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RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: BenB85]
      #5708180 - 03/02/13 04:22 AM

With 90 second exposures and a good-quality 127mm refractor, I'd be expecting a LOT more.

There has to be something you're not telling us.

Yes, the focus is a little soft - you'll get the hang of that with practice. I hope you're using BackyardEOS on a computer as a focus, framing, exposure and overall camera control aid.

I can see severe vignetting and posterization. This usually means the image has been stretched too harshly to compensate for underexposure. What kind of ISO did you shoot at? With your setup, I'd set it to 400 and never change it. If that results in a saturated image at 90 seconds, either incorporate a LPR filter or reduce the exposure time. Look at the resulting histogram - it should be clear of the left side but far from touching the right side.

It's hard to tell if the 'soft' stars are really a focus issue or a guiding/seeing issue. I'd lean toward focus primarily because that's the easiest of the two to remedy.

A 5" refractor and an 1000D should be able to pull out a LOT more than this. You WILL get there.

Good shooting,

Grant


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BenB85
member
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Reged: 02/17/13

Loc: Colorado and Alaska USA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: RedLionNJ]
      #5708186 - 03/02/13 04:33 AM

Hi Grant,

Yeah, I agree about the 127 should be producing a lot more. That's what I don't get. I used a televue .8x reducer too, at iso800. I am in Denver so the images came out bright red when loaded onto the laptop, I'm assuming from light pollution. I figured with this setup, I should be getting bright images even if they are out of focus, so the only thing I can think of is the camera is the issue, but it is astromodified.

Ben


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Smack
super member


Reged: 07/24/09

Re: Whats wrong with my first photo? 5x90sec Orion new [Re: BenB85]
      #5708298 - 03/02/13 08:14 AM

Ben,

Can you please post a single light frame on dropbox or something like that?

I wouldn't mind having a look.

Regards,

Steve


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Alex McConahay
Carpal Tunnel


Reged: 08/11/08

Loc: Moreno Valley, CA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: Smack]
      #5708303 - 03/02/13 08:20 AM

Good effort on the first shot. THe stars are round which means tracking and alignment is good. It could be sharper and the exposure is off. As has been pointed out, getting exposure right in M42 is difficult because of the wide exposure latitude required (High contrast).

Do not go to a different scope. Your apo is a much better scope for learning the ropes than a high focal length SCT. Really. THe scope is not the thing holding you back from even better shots.

Alex


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Patrick
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Reged: 05/16/03

Loc: Franklin, Ohio
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: BenB85]
      #5708369 - 03/02/13 09:10 AM

Quote:

I am in Denver so the images came out bright red when loaded onto the laptop




The images are coming out red because you have a modified camera. All camera makers use a filter over the sensor to block the high end infrared. Modifying the camera removes that filter and makes it more sensitive to the red spectrum. But modifying a camera doesn't put it on steroids. I wouldn't expect too much.

That's not to say you aren't dealing with light pollution and gradients. You most certainly are. Going to a dark sky site always helps with everything!

Patrick


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Jeff2011
Pooh-Bah
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Reged: 01/01/13

Loc: Sugar Land, TX
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: Patrick]
      #5708420 - 03/02/13 09:50 AM

Focusing issues can be easily solved with a bahtinov mask. I have been able to squeeze out some good detail on shorter exposures using StarTools. There is an evaluation copy you can try.

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RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: Patrick]
      #5708476 - 03/02/13 10:23 AM Attachment (13 downloads)

Such an exposure would likely come out bright red for me, too, without any subsequent processing. Maybe the original data is just fine but we're lacking the appropriate post-processing. I dug up some samples I took earlier this year, with a much smaller scope (81mm, F6) and a Canon T2i. The exposure length was a little longer (120s) and the capture ISO was 800. First, here's a "raw" out-of-the-camera:

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RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: RedLionNJ]
      #5708480 - 03/02/13 10:24 AM Attachment (13 downloads)

Then you average 10 of these together, to get:

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RedLionNJ
scholastic sledgehammer


Reged: 12/29/09

Loc: Red Lion, NJ, USA
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: RedLionNJ]
      #5708483 - 03/02/13 10:26 AM Attachment (12 downloads)

Finally, with the application of some levels and curves (not even any darks or flats), you can turn the above into:

Grant


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shawnhar
Post Laureate
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Reged: 06/25/10

Loc: Knoxville, TN
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: BenB85]
      #5708507 - 03/02/13 10:37 AM

Can you provide some more detail on what you did in photshop? One iteration of curves doesn't cut it, you need 10 or 15 applications of curves and levels to bring out detail when it's buried down close to the noise.
I think there is a lot more in there you could pull out with processing.
Flats are really needed, that's what is causing the darkening around the outside.
If you upload the stacked tiff in dropbox and give a link, I think you would be surprised what other folks are able to pull out.


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Smack
super member


Reged: 07/24/09

Re: Whats wrong with my first photo? 5x90sec Orion new [Re: shawnhar]
      #5708567 - 03/02/13 11:06 AM

I imagine the issue is processing. There's likely a lot more data there than you think.

Steve


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Raginar
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Reged: 10/19/10

Loc: Rapid CIty, SD
Re: Whats wrong with my first photo? 5x90sec Orion new [Re: Smack]
      #5708600 - 03/02/13 11:20 AM

Startools is your friend Best 50 bucks you'll spend

For PS, just remember, to first, neutralize the background (set your white/black points), then color calibrate by aligning each color on top of each other.

You've got some good advice so far. Check out Wodaski's or Jerry's books on it. Wodaski's book is kindof expensive since it's out of print but you'll learn a lot on the basics.


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