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K7 Astro (night) photo
Posted By: fillerupmac, 07-22-2009, 03:52 PM

Here's a shot with my K7. Mounted on a Celestron CG5 mount, actually piggybacked ob a small refractor, but not using the refractor as the lens...

I'm not happy with the amount of noise in the photo, but I didn't have a remote, so wound up "gently" holding the shutter for 78 seconds. This weekend I'll try again - longer exposures, less ISO (remote shutter control)

ISO 1600, Tamron 17-50 lens, F3, 78 seconds

A shot of the Milky Way, looking south towards the horizon. This is a very dark site (rare these days) - almost no light pollution. The stars of Sagitarius can be seen on the left.



Comments always welcome!

Al S.
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07-22-2009, 03:56 PM   #2
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WOW! Thats stunning!
07-22-2009, 03:59 PM   #3
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ive found that ISO 1600 shots with low light are very noisy....as you already mentioned try the same with ISO100 and i think you will see a great difference
07-22-2009, 07:18 PM   #4
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Great capture of our galaxy. Too bad for the noise and such. ISO 1600, a 14 megapixel APS-C sensor, and minute-plus exposure is a combination for high-magnitude-star-destroying noise.

If you're fascinated by astrophotography, I suggest you buy a film camera and some Fuji Acros black and white film, as its reciprocity failure isn't even documented by Fujifilm for long-exposures... it's that good, apparently.

07-23-2009, 03:16 AM   #5
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Actually that is an amazingly chrisp shot considering that you held the shutter down by hand. Well done!

Mike
07-23-2009, 03:22 AM   #6
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I find iso 400 night shots way too noisy.
07-23-2009, 07:57 AM   #7
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Original Poster
Thanks for the comments, all

Mike - even I was _amazed_ at the steadiness, I didn't flinch! Even the 100% of this, the stars are still round, and pin points...

More practice this weekend - stay tuned!

Al S.
07-24-2009, 04:20 PM   #8
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Very nice. Perhaps longer exposures at lower ISO and stacked will provide a better image. I am looking forward to your further results. I was considering the K-7 for astro work but I hear it takes automatic dark frames in Bulb mode with no way to turn it off. For long exposures I am still using film. No noise, but albeit, much longer exposures.

Thanks for posting.

07-25-2009, 01:18 PM   #9
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extremely impressive, under the circumstances
07-25-2009, 02:35 PM   #10
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One thing to keep in mind is that the same shot at ISO 100 would not work unless shot from a tripod equipped with a tracking device, as the stars would move far too much. It's not so evident in a wide angle shot, but I once tried to shoot at 200mm and even 10 seconds was far too long.
07-25-2009, 06:10 PM   #11
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Amazing

Can't believe that you can still produce such results, hand pressing the shutter button

Well done
07-25-2009, 08:14 PM   #12
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QuoteOriginally posted by procyon Quote
One thing to keep in mind is that the same shot at ISO 100 would not work unless shot from a tripod equipped with a tracking device, as the stars would move far too much. It's not so evident in a wide angle shot, but I once tried to shoot at 200mm and even 10 seconds was far too long.
I believe this shot was taken "piggyback" on a small telescope. The telescope with it's polar aligned drive tracks the stars accurately enough for many minutes. I have exposed piggybacked cameras 75 minutes with as long as 300mm lenses, tack sharp, corner to corner! Polar alignment is critical for such exposures however.

I wonder if a "slow" ISO setting on the K-7 will produce an almost noiseless image and then stack these images to produce a deep exposure.

Of course this will not freeze the landscape that is within the frame. Experimenting works good here.
07-27-2009, 03:58 AM   #13
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QuoteOriginally posted by nightfly Quote
I believe this shot was taken "piggyback" on a small telescope. The telescope with it's polar aligned drive tracks the stars accurately enough for many minutes. I have exposed piggybacked cameras 75 minutes with as long as 300mm lenses, tack sharp, corner to corner! Polar alignment is critical for such exposures however.

I wonder if a "slow" ISO setting on the K-7 will produce an almost noiseless image and then stack these images to produce a deep exposure.

Of course this will not freeze the landscape that is within the frame. Experimenting works good here.
My bad, totally missed the first sentence of the OP
07-27-2009, 04:10 AM   #14
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I quickly ran that photo from photoshop, did some noise reduction and adjusted the curves.
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