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04-18-2010, 04:28 PM   #91
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QuoteOriginally posted by Shadohh Quote


I understand the focus should be infinity when taking such photos? I guess did not do that, I am also not sure how to do that as I am still new to the camera.

...set the Af switch to 'M', and twist the lens' focus ring to ∞...

04-18-2010, 10:05 PM   #92
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Yeah. Thats how I set it on my Cannon.

I cant seem to find an infinity symbol on my pentax.
04-19-2010, 01:24 AM   #93
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If it is an auto focus lens, aim at something far away and auto focus on it, then turn off AF. Manually focusing an auto focus lens at infinity can be tricky.
04-19-2010, 05:42 AM   #94
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QuoteOriginally posted by pti-andy Quote
There have been many examples posted showing the high ISO performance of the K-x, but not much with long exposures. Noise is much different when the sensor is left on for a while and cameras that perform well with high ISO generally don't fair as well over time.

I just got a new K-x in hopes it would be an improvement and I must say it is nothing short of amazing!
I agree. Great Andromeda shot, btw! Moreover, the K-x is one of the first cameras which allow to photograph the night sky and some foreground at the same time, without star trails!

E.g., this is the Milky Way in 30s (with DA*16-50 at 16mm f/2.8 (same below)).
Taken on a tropical beach with a mini tripod. Using a K-x, ISO 1600 and heavyly pushing levels in post processing.

The glow at the lower half is from the hotel near the beach. In the lower right corner, you see a leave from a foreground tree

In the upper left part, you can see the Andromeda galaxy (M31).


Click on the image to view it in a larger size
(For full size, click onto "O" after having clicked the image)



Another one here: Ocean from a tropical beach in jupiter shine.
Not sun shine, nor moon shine. Jupiter shine!

Needless to say that the entire scene was entirely dark to the naked eye. Shot 4 hours after sunset. The mild red glow at the horizon (even back-illuminating some clouds!) is from moon set which was 5 minutes earlier


Taken with K-x, a 10cm plastic tripod and 30s exposure time. ISO 3200 and levels pushed heavily in post-processing. No noise reduction, though


Click to enlarge


Last edited by falconeye; 04-19-2010 at 05:50 AM.
04-19-2010, 03:57 PM   #95
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Falk,
Nice pictures!
Next time you should try to take multiple shots and then stack them.
The only issue is that the beach would blur if you do this.
Other option would be: take 10 camera, set them up as close as possible, and shoot at the same time and then stack the resulting pictures :-)
04-19-2010, 04:39 PM   #96
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QuoteOriginally posted by MetClub Quote
Other option would be: take 10 camera, set them up as close as possible, and shoot at the same time and then stack the resulting pictures :-)
Isn't this what a large format 50x75mm digital camera does for me? Where is it when I need it?
04-19-2010, 10:09 PM   #97
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Thanks for the reply gimbal! I will try that tonight.

<waits eagerly for 3am>

Last edited by Shadohh; 04-19-2010 at 10:26 PM.
04-21-2010, 06:51 AM   #98
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Jupiter-shine! I believe I have never see that done before. Well, I just got to the Florida Keys with my Kx, and Jupiter is now just rising at dawn, so I will have to give that a shot! Thanks for the inspiration!

04-21-2010, 09:36 AM   #99
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QuoteOriginally posted by outpostbob Quote
Jupiter-shine! I believe I have never see that done before. Well, I just got to the Florida Keys with my Kx, and Jupiter is now just rising at dawn, so I will have to give that a shot! Thanks for the inspiration!
Yeah, I discovered the Jupiter-shine on the photo in post-processing only. Invisible to the naked eye. It shows how much brighter Jupiter is than surrounding stars. Venus is even brighter but Venus may be below horizon with a dark enough sky. Jupiter-shine is more easily done when accepting star-trails.
04-21-2010, 09:56 AM   #100
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a bit noisy but very nice
04-21-2010, 11:26 AM   #101
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QuoteOriginally posted by Shadohh Quote
I cant seem to find an infinity symbol on my pentax.
er... you do have a manual focusing ring (not the zoom) on the lens?

Even if it is not marked,
one end is infinity
the other is something pretty close -
(really hard to mistake one for the other )

Don't forget to set the camera to Manual focus.....
04-21-2010, 02:21 PM   #102
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QuoteOriginally posted by UnknownVT Quote
er... you do have a manual focusing ring (not the zoom) on the lens?

Even if it is not marked,
one end is infinity
the other is something pretty close -
(really hard to mistake one for the other )

Don't forget to set the camera to Manual focus.....
Unfortunately, a lot of newer lenses do in fact have some "past-infinity" wiggle room, so that old rule isn't necessarily reliable.

One trick is to point the camera at something that it simply can't focus on (preferably because it's too dark). The AF will rack the lens through the whole focusing range and then back to (hopefully) infinity. Though you should check that under controlled conditions to make sure it's reliable as well. Once it's at infinity, just switch to MF so it doesn't try to refocus again and leave it alone.
04-21-2010, 03:19 PM   #103
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Jupiter-shine: HDR Opportunity (Venus too!)

Seeme like this might be a dynamite thing to try with the Pentax Kx's High Dynamic Range feature!
04-21-2010, 03:38 PM   #104
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QuoteOriginally posted by er1kksen Quote
Unfortunately, a lot of newer lenses do in fact have some "past-infinity" wiggle room, so that old rule isn't necessarily reliable.
Haven't heard of that one neither of my 2 Pentax lenses focus past infinity -
if they do I cannot see it -
because the depth of field probably would take care of that.

If a lens can be racked past infinity and the Pentax dSLR cannot focus -
why would it focus on infinity - and not just stop at the "infinity end"? -
how would the camera actually know where infinity is anyway - if it can't see well enough to focus -
or is there something amiss with my understanding?
04-21-2010, 04:45 PM   #105
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QuoteOriginally posted by outpostbob Quote
Seeme like this might be a dynamite thing to try with the Pentax Kx's High Dynamic Range feature!
Wouldn't help. After 30s, the stars become star trails and you're better off with a single shot gathering the light within the 30s window.
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