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Astrophotography and Sketching >> CCD Imaging & Processing

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jgraham
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Reged: 12/02/04
Posts: 11575
Loc: Dayton, Ohio
Mizar & Alcor
      #504152 - 07/05/05 07:08 PM Attachment (88 downloads)

Iíve been using Mizar as a focusing target with my DSI and I thought Iíd have a little fun with it. I recently bought a Meade SN6 with UHTC coatings from Meadeís online store and this was also a good opportunity to compare the SN6 with the N6.

The image below was a basic 25x0.5sec exposure with the histogram pretty much maxed out with a range of 0-65,000. I did a little skyglow removal in Photoshop. This shows the SN6 (and the N6) easily splits Mizar and its companion star. Alcor is to the upper left. This is similar to what you see through an eyepiece.

Attachment

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-John

The best advice on imaging I've ever been given... don't forget to look!


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jgraham
Postmaster


Reged: 12/02/04
Posts: 11575
Loc: Dayton, Ohio
Re: Mizar & Alcor new [Re: jgraham]
      #504153 - 07/05/05 07:09 PM Attachment (79 downloads)

This is a 25x15sec exposure taken with the SN6 (6Ē f/5 Schmidt-Newtonian) with the levels set using the ASIPís standard deviation function. The levels were further adjusted in Photoshop. This shows the star images remain pretty clean despite a fairly hefty stretch to bring up the fainter stars.

Attachment

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-John

The best advice on imaging I've ever been given... don't forget to look!


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jgraham
Postmaster


Reged: 12/02/04
Posts: 11575
Loc: Dayton, Ohio
Re: Mizar & Alcor new [Re: jgraham]
      #504156 - 07/05/05 07:11 PM Attachment (70 downloads)

This is a 25x15sec exposure taken with the N6 (6Ē f/5 Newtonian) with the levels set using the ASIPís standard deviation function. The levels were further adjusted in Photoshop. This shows the diffraction spikes coming from the 3-vane spider used to hold the secondary; pretty, but they could be a problem if youíre trying to image something near a bright star. Thereís also a slight field difference between the N6 and the SN6 probably resulting from the flatter field of the SN6.

-John

Attachment

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-John

The best advice on imaging I've ever been given... don't forget to look!


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zjc26138
Loved By All


Reged: 02/24/05
Posts: 6961
Loc: Mingo Junction, Ohio
Re: Mizar & Alcor new [Re: jgraham]
      #504158 - 07/05/05 07:13 PM

Great image.

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TMB130 SS (Currently out of service. )
Celestron Edge 8"
iEQ45m
Meade 102ED
Stellarvue 80/9D

9/11- Never Forget.


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budguinn
Post Laureate


Reged: 11/24/04
Posts: 4895
Loc: Gold Beach, Or
Re: Mizar & Alcor new [Re: zjc26138]
      #504351 - 07/05/05 09:52 PM

John, very nice. I've taken the habit of shooting my last alignment star....I'm already set up and focusing anyway, so why not? I usually do a couple of minutes of shooting so that I can get the star field behind.....I really like the difference in colors in the stars.....such as Vega and Kornephoros.....big difference.

Now, with the SN6, will it always show the interior shadow as well as the spike....from the vanes?

bud guinn

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Warmest regards,

bud guinn
http://www.budguinn.com


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c131frdave
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Reged: 01/17/05
Posts: 4376
Re: Mizar & Alcor new [Re: budguinn]
      #505921 - 07/06/05 08:48 PM

Somebody is having fun! Nice stuff!

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Tak NJP

Various sizes and shapes of formed glass


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jgraham
Postmaster


Reged: 12/02/04
Posts: 11575
Loc: Dayton, Ohio
Re: Mizar & Alcor new [Re: c131frdave]
      #505939 - 07/06/05 09:00 PM Attachment (73 downloads)

Speaking of fun....

The same field... the same telescope (LXD75-SN6) only this time with a Meade LPI. This is 60x10sec exposures aligned and stacked in real-time, dark subtracted, and the histogram left at 0-256. The levels were adjusted and the background processed to reduce thermal noise. The LPI does a respectable job with stellar objects and I can usually reach about 2 magnitudes fainter than I can see visually. Itís also so easy to use itís a lot of fun to tinker with when I donít have a lot of time.

-John

Attachment

--------------------
-John

The best advice on imaging I've ever been given... don't forget to look!


Edited by jgraham (07/06/05 09:00 PM)


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Thick_asa_Planck
Dark Sky Hunter


Reged: 09/04/04
Posts: 3342
Loc: UK
Re: Mizar & Alcor new [Re: jgraham]
      #508431 - 07/08/05 03:51 PM

Nice shot John. i really like your double star images, so keep posting them!

Clear Skies

Alex

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It is often commonplace to leave the notation ambiguous - Anonymous


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