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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Smittty692k4]
      #4813925 - 09/18/11 01:09 AM

Doug, if you could export a TIFF from DSS, then resize/save as JPG without any manipulations in GIMP, we could have a look. Of course it would be better to look at the TIFF, if you have a place where you can store it.

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svtdoug
sage


Reged: 02/07/11

Loc: Gig Harbor, WA, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814039 - 09/18/11 04:26 AM

Alex,

You can download the TIFF from DSS here - Download I am anxious to see what you can do with the image. It is the original stacked image from DSS with no tweaking in DSS.

I've been running a re-stack all evening...(its a long one) but its still running.

Thanks Alex!

Doug


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BLINEAU
super member


Reged: 05/23/11

Loc: Paris, France
Re: AP Images Taken with Original NexStar new [Re: svtdoug]
      #4814090 - 09/18/11 05:57 AM

Hi guys !

I understand this is the place I post now. My last animation (09/16/11) :



Regards
Eric


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: BLINEAU]
      #4814186 - 09/18/11 08:23 AM

Eric, outstanding image and animation. In several frames the details in the bands are clearly visible. Also, the structure around the GRS in the middle of animation shows some details in the wall, so it's not just a spot. There are details both in north and south regions. How many raw frames did you use per animation frame? Thanks.

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BLINEAU
super member


Reged: 05/23/11

Loc: Paris, France
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814257 - 09/18/11 09:34 AM

Thanks Alex,

20 videos in SER format, 5 minutes spaced. In each video, 1200 frames @ 30-35 fps, 800 stacked for each image. I had a registration's problem with Registax6 for the 7th frame of the animation, so 300 frames stacked only for it (unfortunately, the defect is clearly visible in this 7th animation's picture).

Eric


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: svtdoug]
      #4814430 - 09/18/11 11:47 AM

Quote:

Alex,

You can download the TIFF from DSS here - Download I am anxious to see what you can do with the image. It is the original stacked image from DSS with no tweaking in DSS.

I've been running a re-stack all evening...(its a long one) but its still running.

Thanks Alex!

Doug




Doug, I am looking at the FireworksA.tiff from your Google docs site. It appear the image is not oriented the same as the one posted above. When I went to compare my versions and what you posted they looked like images from different stacking. Is that correct?


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814471 - 09/18/11 12:22 PM Attachment (105 downloads)

This is quite a tough target indeed. I tried to control star bloating while trying to squeeze the data from very very dark portion of the image. There is more signal there, no doubt, but getting that signal leads to some non-pleasant looking fireworks. One thing for sure, I did not find a problem with the color balance. The image did not look red. The histogram in Photshop after loading and stretching looked very even. I did only minor color corrections to get the core of the galaxy to neutral grey because it was lacking some blue. The rest of the dark was pretty close to neutral gray already. Thanks for sharing.

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Skip
Starlifter Driver
*****

Reged: 01/23/08

Loc: Fort Worth, Texas, USA
Re: AP Images Taken with Original NexStar new [Re: svtdoug]
      #4814523 - 09/18/11 12:56 PM

Hi Doug,

I dl'd it and worked on it for about an hour in PS. I got the colors aligned pretty well but I couldn't get the detail in the galaxy that you had in the second attempt, without stretching so much that it looked a mess. I tried some noise reduction and that seemed to help a bit but not enough. I used the Despeckle command in PS to do it. I still haven't got Carboni's Actions (PS plug-ins) yet. Some of his stuff is downright magical and may help. I'm going to let it sit for a spell and try again later. But I'm a PS neophyte, so no promises.


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Skip
Starlifter Driver
*****

Reged: 01/23/08

Loc: Fort Worth, Texas, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814547 - 09/18/11 01:04 PM

Alex,

I agree that the colors were pretty well balanced after my intial stretch. But the red histogram was quite a bit broader that the other two. I managed to get them all about the same width. That's what I meant about getting the colors aligned. My end result wasn't too far from yours, except that all my despeckling to get rid of the noise made it a bit fuzzier. Just didn't like it enough to post it. So I deleted it so I could start over. Actually I like your attempt. Might be about all we can do with it.


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Skip]
      #4814600 - 09/18/11 01:34 PM

Skip, I can definitely echo your comments. Getting this image to the state that I posted is quite doable in the first 20-30 minutes. Getting it improved takes hours and result looks only barely better if at all. Since I started processing low signal to noise ratio images like those coming from DSO NexStar, it tells me that we are hitting the limit of what can be achieved given data we have.

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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814695 - 09/18/11 02:30 PM

I apologize for not responding sooner to a couple of PMs related to how I connect my DSLR to the NexStar. I thought a few other people may benefit from this picture:



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Uggbits
sage


Reged: 04/28/10

Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814753 - 09/18/11 03:07 PM Attachment (80 downloads)

I gave a run at the data side of it seeing that the two of you had looked at colour. I think the biggest problem here is there isn't enough integration time, and the calibration didn't control noise properly.

Half of my battle with trying to find signal in this image was dispensing of the noise around it - no easy feat.

Doug, try to grab lots of darks to improve the calibration next time, and supplement that with bias, and (if you know how to do them) flats. This will clean your image so you aren't fighting these other aberrations as you are hunting down the signal. Also, this is an image where 5-8 hours of data is needed to really get into the meat of it. I did 2 hours on it and I was pushing it on processing even then: the noise starts to creep up on you.


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Uggbits]
      #4814769 - 09/18/11 03:15 PM

As Uggbits illustrates very well here, pushing this data just by a few ticks leads to a definite additional signal, but at the expense of any semblance of beauty.

As far grabbing lots of additional darks, the AP gods (Jerry Lodriguss and Samir Kharusi) recommend around 50.

Jerry Lodriguss site
Samir Kharusi Site

Both Jerry and Samir post on CN. Look them up! I read each one of their posts, their results are amazing.

Jerry published a couple of books, but he is always ready to share his knowledge with anyone asking for his advice. He published many chapters from his books online. I butted heads with him a couple of times but eventually had to admit I was wrong on all accounts.

Samir does not have a book (yet), but his observations and comments are always edgy and to the point. No *BLEEP* footing, just raw data, results, and their blunt assessment.

Between Jerry and Samir, the DSLR/CCD forum is a tough crowd to impress. But if you are not into what I describe my kids' American school system "good-try-Johny", then the tough crowd gets everyone's level higher rather than keeping it at a mediocre level. Do not be mistaken, this group on CN is best to none, so that bar is high. There is a group in Italy making some amazing work, but we are yet to make a connection with them.

We have seen some amazing results from the NexStar crowd in the last few weeks, keep them coming guys.


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814831 - 09/18/11 03:42 PM

Don't be shy guys. I am getting PMs on filters and other questions related to imaging with NexStar. Post your questions here without any hesitation, I am begging you.

Specific questions we need to answer is applicability of Ha-filter with NexStar. I will buy one eventually and will try it, but my CFO would murder me if I did it right now. If anyone (hint, hint haytor ) has an access to one, can you post what 30 second samples look like through the C8 OTA? Thanks.


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svtdoug
sage


Reged: 02/07/11

Loc: Gig Harbor, WA, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814850 - 09/18/11 03:51 PM

Alex, Uggbits and Skip,

Thanks guys for all your help and effort to try to get something out of the data. I re-stacked everything last evening with RGB background calibration - but it really didn't help. The galaxy was still red after levels and curves in Gimp and the background was messed up - outer areas turned purple.

I then choose a different reference frame (never have chosen a reference frame before in DSS! Probably should.) and re-stacted overnight. Then in Gimp the Galaxy appeared greenish. Based on that result, AND that both Alex and Uggbits processed and saw no reddish hue, and when I do the processing in DSS I get no reddish color, I can conclude that GIMP is causing the problems with the color.

I appreciate that there just is not enough data there for better results. I will try to capture more if we get some clear skies in the next week or so.

About Dark frames - I used 20 darks. When I stack, I am using the combined dark frame rather than re-stacking the 20 seperate darks. I assume this gives me the same results. Maybe I should try restacking the 20 to see if that give better results??

What version of PS are you all using? Is PS Elements a viable solution, or do you really need the big $ version?

Many thanks for all your help. This imaging stuff is an interesting road, sometimes with major potholes! Currently searching for the expressway!

Cheers,
Doug


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svtdoug
sage


Reged: 02/07/11

Loc: Gig Harbor, WA, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814862 - 09/18/11 03:55 PM

Alex,
Thanks for posting that photo of your filter/T-adapter. I assume the T-adapter slips into the SCT to 2" female adapter. I have the screw in SCT/T-Adapter. When I went to try my new 2" filter it would not thread into the T-adapter. Now I know why. I figured the SCT/T-adapter was the way to go, but now I see the advantage of your setup. Meanwhile I returned the 2" filter to be exchanged for the SCT screw-in type filter. That will work but won't on another future scope like a refractor. The filter is a Astronomik CLS filter - probably should get the type that fits right into the camera. Disadvantage then is I won't be able to use it visually. Maybe call them tomorrow and see if I can change that order.

Thanks!
Doug


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Smittty692k4
Pooh-Bah
*****

Reged: 07/05/11

Loc: East Bernard, TX
Re: AP Images Taken with Original NexStar new [Re: svtdoug]
      #4814867 - 09/18/11 04:00 PM

Thanks for posting that pic Alex. Looks so simple now.

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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: svtdoug]
      #4814902 - 09/18/11 04:20 PM Attachment (72 downloads)

Doug, I have both Photoshop CS3 Full version and the PS Elements. I was able to get the CS3 while still affiliated with academia at a deep deep discount. There is no way I would be able to buy it now. That is why I bought PS Elements earlier this year.

The real reason I keep using CS3 is ability to adjust Curves. PS Elements does not allow random point on the curve selection. In CS3 I can Ctrl-Click anywhere on image and it places a control point on the curve. If you look on page 14 and 15 in this guide to imaging with NexStar it shows how easy it is to extract minor feature details. Elements is still useful with ability to work with curves, but nowhere close to full version PS.


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svtdoug
sage


Reged: 02/07/11

Loc: Gig Harbor, WA, USA
Re: AP Images Taken with Original NexStar new [Re: Alex Post]
      #4814941 - 09/18/11 04:35 PM

Thanks Alex,

A quick check on ebay and you can pick up CS3 pretty cheap - around $20. Don't know if there is a down side to that?? I also see CS3 Extended, not sure if that would be useful. So much to learn...

I have used your guide a lot for getting started, but have not read the PS part carefully because I don't have the software. I'll dig into it more now - as that is likely the route I will take.

Many thanks.
Doug


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: AP Images Taken with Original NexStar new [Re: Smittty692k4]
      #4814954 - 09/18/11 04:40 PM

Quote:

Thanks for posting that pic Alex. Looks so simple now.


Haha, believe it or not but that was an accidental discovery when I was trying to connect the parts I had. I spent many hours dwelling on how I could do filters with my setup.

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