Long exposure night sky question

Peeb

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Took an 8 minute exposure tonite and the sky has striations- kinda like 'strata' in the sky. I've played with the exposure and white balance to accentuate it:
MJK_6949_small.jpg


Is this normal, or an issue with my sensor??
 
I can reduce it significantly by darkening the sky.
MJK_6949_new3-small.jpg
 
Are you talking about the star trails???? If so the long exposure reflected the earth's rotation in relation to the star location. My K3II has the Astrotracer function that will shift the sensor slightly to keep the star in place. I haven't tried it yet, to tell you how well it works. The examples I've seen look great, however, you still can't have both the stars and landscape sharp. Shifting the sensor keeps the stars in focus, but blurs the landscape. I've done something similar, with a composite image where both are sharp.
 
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Try adding a touch of grain to avoid the posterization (instead of darkening it)?
 
I agree, the lines in the sky look like posterization. The star trails look normal.
 
Star Trails look normal for 8 minutes.

Posterization due to the ground lighting gradient up is the problem for the JPEG compression (from my limited knowledge on posterization).

Have everyone in a 50 mile radius turn off all the lights.

Shooting later than 9pm at night too would help. Pick the middle time between dusk and dawn.

The black slider in LightRoom works well too.
 
Are you talking about the star trails???? If so the long exposure reflected the earth's rotation in relation to the star location. My K3II has the Astrotracer function that will shift the sensor slightly to keep the star in place. I haven't tried it yet, to tell you how well it works. The examples I've seen look great, however, you still can't have both the stars and landscape sharp. Shifting the sensor keeps the stars in focus, but blurs the landscape. I've done something similar, with a composite image where both are sharp.
No, star trails are a different issue entirely. I'm talking about 'strata' of dark background. Yes, the stars will make a 'streak' if you leave the shutter open for 8 minutes, but this was neither a problem nor a surprise.
 
Looks to me like you lessened the star trails. To avoid star trails, you will have to do shorter exposures due to the earth's rotation. There is a formula to help with this. How To Avoid Star Trails - The 500 Rule
Yeah, this isn't the issue here, Ron. Let post an image to REALLY accentuate the issue:
MJK_6949 posterize.jpg


I'm talking about the parfait layers of sky- not the stars.
 
Star Trails look normal for 8 minutes.

Posterization due to the ground lighting gradient up is the problem for the JPEG compression (from my limited knowledge on posterization).

Have everyone in a 50 mile radius turn off all the lights.

Shooting later than 9pm at night too would help. Pick the middle time between dusk and dawn.

The black slider in LightRoom works well too.
Winner! OK- so this is apparently a normal artifact of light pollution.
 
Are you talking about the star trails???? If so the long exposure reflected the earth's rotation in relation to the star location. My K3II has the Astrotracer function that will shift the sensor slightly to keep the star in place. I haven't tried it yet, to tell you how well it works. The examples I've seen look great, however, you still can't have both the stars and landscape sharp. Shifting the sensor keeps the stars in focus, but blurs the landscape. I've done something similar, with a composite image where both are sharp.
No, star trails are a different issue entirely. I'm talking about 'strata' of dark background. Yes, the stars will make a 'streak' if you leave the shutter open for 8 minutes, but this was neither a problem nor a surprise.

Ok, now that you posted the last image I can see what you're talking about. Strange I wasn't seeing it on the first image.
 
Are you talking about the star trails???? If so the long exposure reflected the earth's rotation in relation to the star location. My K3II has the Astrotracer function that will shift the sensor slightly to keep the star in place. I haven't tried it yet, to tell you how well it works. The examples I've seen look great, however, you still can't have both the stars and landscape sharp. Shifting the sensor keeps the stars in focus, but blurs the landscape. I've done something similar, with a composite image where both are sharp.

Astrotracer will move the sensor to counteract the apparent movement of the stars, but that would have blurred the foreground. I'm not a fan of star trails but I'd prefer them to loosing the landscape here.
Unfortunately the used O-GPS I got had a faulty compass so couldn't be used for Astrotracer with my K5ii. I was lucky enough to find someone who was only after the geotagging function & get most of my money back. Where there's no foreground Astrotracer can give some fantastic results, I hope to have another go at it sometime.
 

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