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Old Aug 12, 2007, 6:46 PM   #1
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So it's the perseids meteor shower tonight, so I thought I would try my luck as I am also into astronomy. Set up the camera, few test shots, get comfortable and...

30 second exposures take nearly 20 seconds to process and save! I was going to do a star-trails photo, but well... look at the attached image below...

Is this normal? am I better off just getting a shutter release, and setting it to ISO1600 (shudders) and 5 seconds continuous shoot?
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Old Aug 12, 2007, 7:08 PM   #2
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that is odd.. haven't a clue what would cause it. the perseids are suppose to peak after midnight.

roy
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Old Aug 12, 2007, 9:04 PM   #3
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That's a weird pattern - I've never seen something like that (I've never done star tracks). Did you have SR on? I can't imagine that it would make a difference to have a shutter release (especially if you use the 2 second lock-up) but think the SR might have some effect.

As far as how long to process - if you have the noise reduction option turned on it will take much longer to process the picture. From what I understood, the camera "takes" another picture, around the same time as the picture, with the shutter closed, then a program in the camera compares the noise and hot pixels from this to the picture you took and adjusts the picture accordingly. I went back to the owners manual to verify this but could only find a few not-very-clear references to the noise reduction option (same in both the K10 and K100 manuals).

Magic Lantern K10 Guide is slightly more informative: "When this feature is active, additional in-camera processing, using different algorithms, will be applied only for long exposures. This will minimize the 'grainy' effect with special blurring to make the pattern much less noticeable. However, there is one drawback" this process creates a slightly softer image." (p.87, Magic Lantern Guides Pentax K10D, Peter K. Burian).

Try turning the Noise Reduction option off (custom menu) and your pictures won't take so long to process (who knows, it might also take care of your problem, but you'll have more noise). Worth a try anyway.
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Old Aug 13, 2007, 3:30 AM   #4
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That's a composite of 4 images, the gaps are where the camera was taking so long to process the file before I could shoot again. Surprising how far the sky moves in 20 seconds!

I didn't think of the noise reduction, I will give it another try tonight (no meteors but I can still try the star trails)

Thanks
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Old Aug 13, 2007, 6:58 AM   #5
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If that is four separate images, then everything looks fine to me. I believe previous posters were trying to figure out why the stars all appeared as four dots, now we understand. I have not done anything like this but my recommendation would be to get a cheap cable shutter button, put the camera in bulb mode, turn off the NR feature, and lock the shutter open with the cable release.

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Old Aug 13, 2007, 7:26 AM   #6
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Yeah I didn't explain the photo properly, sorry!

I will try it again tonight if the weather is nice (just been raining) I actually tried a Bulb mode photo just holding the button down, and there wasn't any noticable shake, probably because it's quite a hefty tripod. But yeah, I don't fancy trying a 30 minute exposure holding the button down, so will go ob eBay tonight and get a cable release!
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