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PostPosted: Thu Jan 07, 2016 2:50 pm 
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Joined: Sat May 02, 2009 2:37 pm
Posts: 158
Are there any preferred settings for constellation photography?

I'd like to get some images of constellations (Orion, etc) and am thinking that f2.8 at ISO 800 (or faster?) for an exposure of 5 - 10 seconds should do it?

Geoff :)


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PostPosted: Thu Jan 07, 2016 3:36 pm 
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Joined: Mon Jan 18, 2010 9:25 am
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It depends how good the camera is at high ISO.
10 seconds yes on a fixed tripod. Maybe f/4 better stars.
Some cameras such as Sony A7S are good at 25,000 ISO.

Distortion free or in camera corrected lenses are best.

Regards, David.


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PostPosted: Thu Jan 07, 2016 6:22 pm 
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Joined: Fri Dec 03, 2004 9:58 pm
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Location: Wellingborough
As David said :)

With the relatively short shutter times you would use with a stationary camera to keep star drift within tolerable limits it's straightforward to bracket your exposures in terms of time, aperture, ISO and maybe focal length then select the best combination(s) for future use. Don't forget to use the cameras shutter delay to allow vibration to subside before data collection starts.

One word of advice, switch off the camera's automatic noise reduction routine if it's present. It's better to deal with images using software on your computer afterwards. I read that some cameras inbuilt noise reduction has a tendency to regard stars as noise and deal with them accordingly :roll:

Regards

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PostPosted: Fri Jan 08, 2016 9:41 pm 
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Hi,

I use a 50mm lens at f1.4 with an exposure of 8 sec with the ISO set at 6400. I take about 30 images and then stack them. I get down to about mag 10 stars.

For a bigger image for parts of a constellation (ie. an open cluster, M45, M35, M37, M38), I use a 150 mm lens at f2.8, with an exposure of 2.5 sec, ISO again 6400.

Hope that helps

David


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PostPosted: Sat Jan 09, 2016 3:02 pm 
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Joined: Mon Jan 18, 2010 9:25 am
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Sony A7S Mk I, 85mm f/1.4 Samyang at f/1.4.
1/20 second at ISO 51,000 8th mag stars. Single exposure.
51,000 ISO very good photos and best setting.
Stars good to corners with this short exposure at f/1.4.

Viewfinder shows stars 40 times fainter than unaided eyes with 85mm at f/1.4.
In fact no stars visible unaided eyes, many in viewfinder.

Trouble is it is so sensitive I get an image of myself in the window.

I have a Lens skirt, which I hope will solve this. Sticks to window.

102,000 ISO also good. 204,000 and 409,000 ISO bad.

For normal images, auto chooses either 100 ISO or 12,800 ISO and little difference.

Video users should get Mk II version.

50mm and 85mm modern lenses fairly distortion free on APS format. Especially centre portion.

Regards, David


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