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Old 01-02-2017, 10:09 PM
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traveller (Bo)
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Half cooked chook

IC 2944, better known as the Running Chicken Nebula.
About 90 mins of data at 2 min per sub at 1600 ISO.
Horrible field rotation to the left which I didn't really notice until all the stacking was done
Still, happy to get this far.
Bo
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  #2  
Old 01-02-2017, 10:47 PM
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iborg (Philip)
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Hi Bo

The image looks pretty good to me.

I don't know what field rotation looks like, and I can't see anything in the image that I can identify as that.

So, could you be a bit more specific about where on the left you can see it?

I would much appreciate it, as I have wondered what it looks like for some time.

Thanks,

Philip
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Old 02-02-2017, 09:34 AM
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ZeroID (Brent)
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Hi Phillip,
In case Bo doesn't get back to you take a look at the stars on the left side near the edge and see the slightly stretched oval shape they have.
If you check them out vertically you will perceive a slight curvature to the effect top to bottom.
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Old 02-02-2017, 09:43 AM
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iborg (Philip)
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Hi Brent

Thanks for the response. I think I am seeing the effect.

It looks to me as though -
towards the top of the image, the ovals tend from top right to bottom left

middle of the image, ovals fairly vertical

bottom of the image from top left to bottom right

Does this sound correct?
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Old 02-02-2017, 11:05 AM
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traveller (Bo)
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Thank Brent,
Yes Phillip, what you noticed with the "stretched" stars (eggy stars or elongated stars as other call them) is that they tend to form a rotation pattern. This is particularly noticeable towards the bottom left of the image as Brent has picked up.
Field rotation is usually caused by poor polar alignment and poor guiding (as a result of poor polar alignment).
Lesson for me is to slow down and do a proper drift alignment before guiding...
Bo
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Old 02-02-2017, 11:57 AM
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iborg (Philip)
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Hi Bo

Thanks for confirming that for that.

I will to keep eye out for it when I do eventually get to take some images.

Mind you, I would be very happy if that was all that was the worst part of the image.

Have fun

Philip
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  #7  
Old 02-02-2017, 01:43 PM
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traveller (Bo)
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Thanks Phillip.
AP is great when it works but PITA when it doesn't.
Bo
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Old 02-02-2017, 02:28 PM
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iborg (Philip)
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Even visual is a PITA when the clouds keep rolling in while I'm trying to look at Vesta!!
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  #9  
Old 02-02-2017, 02:47 PM
Mosc_007 (Charles)
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A great job with lots of detail. The Field rotation is minimal.

With less detail the Running Chicken is very visible. But more detail you can't really see it.
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