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mspk7305
newbie


Reged: 01/22/14

Am I out of focus? Collimated badly? new
      #6328703 - 01/22/14 03:41 PM

Ive just started using my 8 inch SCT. Wondering if what I am seeing here is correct... These are various shots of Sirius and Betelgeuse at various levels of iso and exposure. Was taking these from prime while testing out things. I am wondering if the way I am picking up these stars is correct for an SCT. Ive been told (at reddit.com/r/astrophotography ) that the stars in an SCT wont have the X flares on them, but what I am wondering is if I need to adjust the telescope any more.

I know these photos are out of whack for iso and exposure, was testing to see how much noise it would make at various settings.

http://imgur.com/a/xCA8s


Best examples of what im seeing http://i.imgur.com/EYcawzZ.jpg and http://i.imgur.com/bgwr3nm.jpg

There was a fair amount of vibration from the dogs running around in some of those shots, I assume that accounts for the wobbles in some of the stars?

Telescope is an EdgeHD800 on an Advanced VX. I've already got vibration pads on the way.


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StrangeDejavu
Carpal Tunnel
*****

Reged: 03/20/13

Loc: Florida
Re: Am I out of focus? Collimated badly? [Re: mspk7305]
      #6328713 - 01/22/14 03:47 PM

It looks like it may be slightly off. Have you done a star test on it yet? Sirius makes a great candidate due to its brightness. You can check this by focusing a bright star, and slowly backing in (or out) of focus until you see a concentric ring pattern. This image shows perfect collimation, you should aim for something like this.

It's best to do this test through your longest focal length eyepiece -- I use a 4.7mm to check mine.


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mspk7305
newbie


Reged: 01/22/14

Re: Am I out of focus? Collimated badly? new [Re: StrangeDejavu]
      #6328875 - 01/22/14 04:56 PM

thanks, ill check my eyepiece against the image

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