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First Image from my Nikon D5300 and Pix Insight

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#1 Gregk

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Posted 18 March 2017 - 01:26 AM

Hi

 

First Image from my Nikon D5300 and Pix Insight

 

Really like PI. After using PS and CS for many years the learning curve

wasn't as bad as I thought.

 

Histogram Transformation stretch

Dynamic background extraction

Curves Transfomation for RGB stretch and Satuartion

Morphological Transformation - star shrink

ACDNR noise Reduction

20 x 5 minutes Nikon D5300 stock

 

DSS_Rosette_generic_color_DBE NR fin.jpg

 

 

 

 


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#2 starbob1

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Posted 18 March 2017 - 07:48 AM

I use a 5300 also. Your image is not bad but It seems the background is different at the bottom than the top. The stars at bottom are bright but at top dim. Good job.



#3 CodeBlind

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Posted 18 March 2017 - 09:32 AM

Nice start, especially on a dim target like the Rosette Nebula! What lens/telescope were you shooting through when you took this?

A little constructive feedback - it looks to me like you might have a centering issue in the optical train. It's almost like the image is less focused in the bottom than it is on top, like a camera lens element is offset from the others. Either that, or maybe there was a bright gradient that started strong near the top top and weak at the bottom in the original? Gradient removal can sometimes cause similar star brightness issues if the original gradient was bad enough.

Even so, no knocks here - you really are off to a good start!

Edited by CodeBlind, 18 March 2017 - 09:35 AM.


#4 ismosi

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Posted 18 March 2017 - 10:20 AM

I agree with CodeBlind. The top seems darker than the bottom. Did you use flats?

 

Congrats on climbing the PI learning curve so quickly. As you've found out it's not so bad, plus, these days there is so much support material either free or paid.

 

Did you use BYN for acquisition?


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#5 Gregk

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Posted 18 March 2017 - 12:38 PM

I use a 5300 also. Your image is not bad but It seems the background is different at the bottom than the top. The stars at bottom are bright but at top dim. Good job.

Thanks......Maybe a camera to lens tilt?



#6 Gregk

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Posted 18 March 2017 - 12:43 PM

Nice start, especially on a dim target like the Rosette Nebula! What lens/telescope were you shooting through when you took this?

A little constructive feedback - it looks to me like you might have a centering issue in the optical train. It's almost like the image is less focused in the bottom than it is on top, like a camera lens element is offset from the others. Either that, or maybe there was a bright gradient that started strong near the top top and weak at the bottom in the original? Gradient removal can sometimes cause similar star brightness issues if the original gradient was bad enough.

Even so, no knocks here - you really are off to a good start!

Thanks....I used an AT 65mm refractor w/built in flattner. Possibly the camera to first scope lens was tilted...Not sure how to

guarentee sensor to scope lens flatness..



#7 CodeBlind

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Posted 18 March 2017 - 06:42 PM

If things seemed pretty tight and rigid when you started shooting, that can definitely be a tough thing to nail down.  Maybe try taking one shot of a star field, then rotate the camera 180 degrees while keeping the scope pointed at the same stars and shoot again.  If the bigger stars follow the re-orientation of the camera (e.g. move from the top to the bottom of the sensor), then it's probably just the weight of the camera causing flexure in the tube.  A lighter camera or a beefier focuser might fix something like this.  If the bigger stars don't move in the image with a change in camera orientation, then it's probably a centering issue in one or more of the telescope lens elements and might require a trip back to AstroTech to fix.



#8 bobzeq25

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Posted 20 March 2017 - 02:23 AM

Did you really do a HistogramTransformation stretch before DBE?  That's not good, you want DBE to operate on a linear (unstretched) image, it does computations that don't work well if the data has been stretched.  That's likely why you have the large gradient.

 

Use the ScreenTransferFunction to visualize the data (it doesn't actually stretch it), DBE, (possibly BackgroundNeutraliztion and ColorCalibration which also work better on linear data), and then stretch.

 

This book is superb.

 

https://www.amazon.c...y/dp/3319256807


Edited by bobzeq25, 20 March 2017 - 02:24 AM.



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