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Thread: astrophotography

  1. #1
    Senior Member viablex1's Avatar
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    astrophotography

    anybody here doing it?

    it looks cool as heck

    matto

  2. #2
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    Re: astrophotography

    Matto,
    I have done some.
    There are many flavors from wide field to high res lunar and planetary imaging.
    It can involve some pretty interesting gear. Image processing can also be very complex.

    Are you interested in anything specific?
    PT

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    Senior Member danielmoore's Avatar
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    Re: astrophotography

    This reminds me to build a barn door tracker. It seems a relatively easy way to avoid trails when you don't want them.

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    Re: astrophotography

    I think I started a thread about the barn door some time ago.
    http://forum.getdpi.com/forum/gear-g...s-cheaply.html

    Been thinking about night sky photography for a while. For US$600 this is possibly some of the best I've found... eliminates star trails...
    Vixen Optics Polarie Star Tracker with Tripod 35505P1 B&H Photo

    Now I'm wondering how good the samyang 14mm lens is at night sky. I think the 14-24 is probably very good from what I've noticed of photos here. Nikon 20mm has a lot of coma wide open, very little at 5.6.

    Hope to photograph these 2 comets arriving in March and December 2013, the later might be daytime visible, & very bright & very big at night...
    http://forum.getdpi.com/forum/sunset...ts-2013-a.html

  5. #5
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    Re: astrophotography

    I do wide-field astrophotography. What do you want to know?

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    Senior Member danielmoore's Avatar
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    Re: astrophotography

    I've done 20-30 sec. exposures at wide apertures and even at these shorter night time durations it seems to me a barn door mount would help to better define those close but not quite pointed poiinted of light.

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    Re: astrophotography

    If you want pinpoint stars, you need a tracking mount.


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    Re: astrophotography

    This shows sky motion for a 60 sec. exposure. The yellow cast to the sky is natural sky glow. But with rotation, you can still make out the Orion nebula, even with a 20mm lens on an E-P1.


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    Re: astrophotography

    And just shooing under moonlight is fun.


  10. #10
    Senior Member johnnygoesdigital's Avatar
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    Re: astrophotography

    If just using a camera and tripod, try pointing the camera at the north star (Polaris) in the northern hemisphere to keep star movement minimal.

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    Re: astrophotography

    Ive been shooting this kind of stuff for a few years, and by no means would I call myself an expert.

    As others have said- there are many levels of difficulty, and the gear can get pretty intense, same goes for the processing. Simple rule of thumb: The higher the magnification- the harder ( and more expensive ) it gets.

    I've attached a few images below:

    The first image is the simplest set up, a 30sec image shot from a tripod:

    Nikon D4, Nikkor 8mm/2.8AIS @ f4 ISO 1600. The stars are sharp since the sky moves 1/8 of a degree during the exposure, but with this lens each pixel's FOV is .23 degrees, so the star trail length is less than a pixel for this lens/exposure combination.

    In the frame you can see my wide-field CCD rig set up at a dark-sky site.

    There are two telescopes on the payload side of the mount, a 500mm f5 refractor is the primary imaging scope, and behind it is a smaller 355mm f5.6 guide scope. The boxy looking thing at the back of the main scope is the CCD camera.

    There's also a smaller camera attached to the guide scope that allows the laptop to adjust the mount's tracking and keep the primary locked to it's target.

    The second image, a 30min Hydrogen Alpha exposure of the Swan nebula, was shot with this set up. The CCD chip is cooled to minimize thermal noise, and the total exposure is made up of 6 5min sub exposures that are individually calibrated then combined to form the final the frame.

    The color image of the Orion nebula: 80min of total exposure, was shot on film ( Ektachrome 200 ) using the same imaging scope, but a smaller mount. 3 hand guided subs were combined: 36, 24 and 4 minute exposures.

    After a few seasons sitting in the cold next to the rig, hand guiding for hours- I eventually upgraded the mount to an auto-guider system.

    HTH,
    -m
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    Re: astrophotography

    Here's a better image of the rig:

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    Re: astrophotography

    Very nice rig. There is just something special about Takahashi.

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