White spots in the sky

Andovis · 06-04-2011, 04:30 AM

Hello,

I have a Pentax K-5 + 18-55 that sometimes shows white spots on images, but only when the subject is the sky. It only happens sometimes, and the occurence of white spots differs. It only happens when I've taken a photo of the sky, never in other situations. The camera has been in for service for this problem, but they didn't find any problems or faults. They have also cleaned the sensor.
My question is: What are these white spots? I'm not sure it is a fault, but I don't find any explanation of what it is.

Kind Regards
Andreas

Attached Images

**Ash** · 06-04-2011, 04:46 AM

Welcome to the forum.
This issue is unusual. Since it occurs intermittently, it is not a physical problem like dust or smears. But since it also occurs in different spots makes me wonder whether there is something electrical or within the sensor that is producing these wierd spots. You're sure the sky doesn't have these spots as little clouds when you're shooting it, right?

Probably best to take a photo of something even more homogeneous, like a dark grey or black page, underexposing it to look for the white spots, and trying different apertures to test how it appears with the lens stopped down.

Adam · 06-04-2011, 06:01 AM

Maybe this is dust/damage to the lens? Doesn't look like sensor dust to me.

Andovis · 06-04-2011, 06:25 AM

I have checked other images and can't see the same thing there. Maybe it's something in the air that the camera can see. Because of that, it's not a big problem.

**Ash** · 06-04-2011, 07:26 AM

Try rocket blowing the insides of the camera and rear lens element clean anyway and see if it makes any difference.

JeffJS · 06-04-2011, 07:36 AM

I think dust anywhere in the light path is going to show up black or at least dark. It would have to be Huge to be on the lens and to have any real affect on photos.

What do the spots look like blown up? Just plain white spots?
Have you tried a different card?
Are you using a filter on the lens? (could this be Lens Flare?)
How do you know that this doesn't occur in any other types of photos?
Are the spots always in the same place?
Do they show up in the RAW PEF (or DNG) files?

rormeister · 06-04-2011, 07:52 AM

Perhaps you can try taking a long exposure, in a dark place, with the lens cap on, SR off, on tripod to eliminate any possibility of shake/motion and see if any bright spots result. That will most likely eliminate any electronic failure. Secondly, what image processing software are you using? Can you reproduce this effect using a different image processor on the same affected image?

**Ahab** · 06-04-2011, 07:58 AM

Look like UFO's to me

Andovis · 06-04-2011, 12:33 PM

The spots are white and sometimes a bit gray. They vary in size, place and occurrence. Most of the time when I take a picture of the sky no spots are visible. It only happens sometimes, so I don't think that something is wrong with the camera. I have tested with different cards and without UV-filter, but it's difficult to test so many times to reproduce the spots. I have also checked my other photos and couldn't see any spots on them.

**germar** · 06-05-2011, 06:26 AM

Have we ruled out the chance there really is something in the sky when the shot is taken?
I've seen similar images and the spots were birds in flight. Since they are always random, only when you're shooting the sky and you can't duplicate the same spot locations from shot to shot, it sure sounds like something physical being captured by the lens and sensor. Maybe flying insects?

Andovis · 06-05-2011, 08:50 AM

Yes, could it be as germar describes? Maybe my eyes can't see it, but my camera can when i take a photo at 55 with 18-55.

yusuf · 06-05-2011, 10:04 AM

Looks like dust on lens or filter and hence you are seeing at different places at different time due to rotation - my guess.

peasant · 06-05-2011, 05:38 PM

I have the spots too,to replicate shoot the sky at f14(ish)through to f22.I can do this with different lens,gray or blue sky.It doesn't seem to be an issue at any other time.

Andovis · 06-06-2011, 01:26 AM

Do you also have white spots? My photos are taken at F5.6.

peasant · 06-06-2011, 01:55 AM

Originally posted by Andovis

Do you also have white spots? My photos are taken at F5.6.

No,mine are more a pale grey but it was overcast here all day.Nothing for me at f5.6.

06-04-2011, 04:30 AM	#1
Andovis New Member Join Date: Jun 2011 Posts: 5	White spots in the sky Hello, I have a Pentax K-5 + 18-55 that sometimes shows white spots on images, but only when the subject is the sky. It only happens sometimes, and the occurence of white spots differs. It only happens when I've taken a photo of the sky, never in other situations. The camera has been in for service for this problem, but they didn't find any problems or faults. They have also cleaned the sensor. My question is: What are these white spots? I'm not sure it is a fault, but I don't find any explanation of what it is. Kind Regards Andreas Attached Images

06-04-2011, 06:01 AM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Maybe this is dust/damage to the lens? Doesn't look like sensor dust to me. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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06-04-2011, 04:46 AM	#2
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Welcome to the forum. This issue is unusual. Since it occurs intermittently, it is not a physical problem like dust or smears. But since it also occurs in different spots makes me wonder whether there is something electrical or within the sensor that is producing these wierd spots. You're sure the sky doesn't have these spots as little clouds when you're shooting it, right? Probably best to take a photo of something even more homogeneous, like a dark grey or black page, underexposing it to look for the white spots, and trying different apertures to test how it appears with the lens stopped down.

06-04-2011, 06:25 AM	#4
Andovis New Member Join Date: Jun 2011 Posts: 5 Original Poster	I have checked other images and can't see the same thing there. Maybe it's something in the air that the camera can see. Because of that, it's not a big problem.

06-04-2011, 07:26 AM	#5
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Try rocket blowing the insides of the camera and rear lens element clean anyway and see if it makes any difference.

06-04-2011, 07:36 AM	#6
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	I think dust anywhere in the light path is going to show up black or at least dark. It would have to be Huge to be on the lens and to have any real affect on photos. What do the spots look like blown up? Just plain white spots? Have you tried a different card? Are you using a filter on the lens? (could this be Lens Flare?) How do you know that this doesn't occur in any other types of photos? Are the spots always in the same place? Do they show up in the RAW PEF (or DNG) files?

06-04-2011, 07:52 AM	#7
rormeister Veteran Member Join Date: Dec 2007 Location: USA Photos: Gallery Posts: 626	Perhaps you can try taking a long exposure, in a dark place, with the lens cap on, SR off, on tripod to eliminate any possibility of shake/motion and see if any bright spots result. That will most likely eliminate any electronic failure. Secondly, what image processing software are you using? Can you reproduce this effect using a different image processor on the same affected image?

06-04-2011, 07:58 AM	#8
Ahab Site Supporter Join Date: Jul 2007 Location: Arnold, Md. Photos: Gallery \| Albums Posts: 762	Look like UFO's to me

06-04-2011, 12:33 PM	#9
Andovis New Member Join Date: Jun 2011 Posts: 5 Original Poster	The spots are white and sometimes a bit gray. They vary in size, place and occurrence. Most of the time when I take a picture of the sky no spots are visible. It only happens sometimes, so I don't think that something is wrong with the camera. I have tested with different cards and without UV-filter, but it's difficult to test so many times to reproduce the spots. I have also checked my other photos and couldn't see any spots on them.

06-05-2011, 06:26 AM	#10
germar Site Supporter Join Date: Apr 2007 Location: North Palm Beach, Florida Photos: Gallery Posts: 728	Have we ruled out the chance there really is something in the sky when the shot is taken? I've seen similar images and the spots were birds in flight. Since they are always random, only when you're shooting the sky and you can't duplicate the same spot locations from shot to shot, it sure sounds like something physical being captured by the lens and sensor. Maybe flying insects?

06-05-2011, 08:50 AM	#11
Andovis New Member Join Date: Jun 2011 Posts: 5 Original Poster	Yes, could it be as germar describes? Maybe my eyes can't see it, but my camera can when i take a photo at 55 with 18-55.

06-05-2011, 10:04 AM	#12
yusuf Pentaxian Join Date: Nov 2008 Location: Palo Alto, CA Photos: Gallery Posts: 2,497	Looks like dust on lens or filter and hence you are seeing at different places at different time due to rotation - my guess.

06-05-2011, 05:38 PM	#13
peasant Forum Member Join Date: Aug 2009 Location: adelaide Photos: Albums Posts: 89	I have the spots too,to replicate shoot the sky at f14(ish)through to f22.I can do this with different lens,gray or blue sky.It doesn't seem to be an issue at any other time.

06-06-2011, 01:26 AM	#14
Andovis New Member Join Date: Jun 2011 Posts: 5 Original Poster	Do you also have white spots? My photos are taken at F5.6.

06-06-2011, 01:55 AM	#15
peasant Forum Member Join Date: Aug 2009 Location: adelaide Photos: Albums Posts: 89	Originally posted by Andovis Do you also have white spots? My photos are taken at F5.6. No,mine are more a pale grey but it was overcast here all day.Nothing for me at f5.6.