Persistent Blemish

GeoJerry · 09-02-2012, 11:02 PM

I just got a K-5 abut a month ago. The first time I used it it seemed fine. However, last week on a trip to Iceland I noticed that many pictures were showing up with a small circular blemish in the same position, regardless of what lens I was using. I'm attaching an example - see the little dot just to the left of center in the to part of the picture?

I'm guessing that I must have a sensor issue, or could it be something between the sensor and the lens... or alternatively software related (as it doesn't always seem to show up).

On an unrelated issue, I noticed that many autofocus images of glacial ice seemed out of focus. These were shots of small icebergs in a lagoon that were floating from 100-400 feet away from me. Is this a known issue?

Any insights?

creampuff · 09-02-2012, 11:12 PM

dust on your sensor, get a blower. You can clone it out with post processing software.

**baro-nite** · 09-03-2012, 02:45 AM

Looks like dust all right. As to the icebergs and focus, ice isn't generally a very contrasty subject and AF may well have trouble latching on to it.

GeoJerry · 09-03-2012, 09:49 AM

Thanks for the quick feedback. I suspected as much, but I didn't want to go into my camera's innards until I heard back from a few people who know more than I about the subject!

Stefanyshyn · 09-04-2012, 07:16 AM

Not wanting to overlook the obvious, but do you have the automatic sensor cleaning option checked off, and have you tried using the cameras built in sensor cleaning function?

Also, there was recall of K5's back January 2011 for water drops on the sensor. I don't think this is your problem but worth looking into (To PENTAX K-5 Digital SLR Camera Users | PENTAX RICOH IMAGING)

GeoJerry · 09-07-2012, 10:42 PM

Originally posted by Stefanyshyn

Not wanting to overlook the obvious, but do you have the automatic sensor cleaning option checked off, and have you tried using the cameras built in sensor cleaning function?

Also, there was recall of K5's back January 2011 for water drops on the sensor. I don't think this is your problem but worth looking into (To PENTAX K-5 Digital SLR Camera Users | PENTAX RICOH IMAGING)

Yes, I did try to use the sensor cleaning function but it was unable to dislodge this bit of dust. I do have the clean at startup option checked.

I was able to get rid of the dust though with an air bulb blower. I was in a very dry windy are with lots of powder sized dust, that must have been it.

09-02-2012, 11:02 PM	#1
GeoJerry Veteran Member Join Date: Dec 2011 Location: Santa Barbara, CA Photos: Gallery Posts: 5,158	Persistent Blemish I just got a K-5 abut a month ago. The first time I used it it seemed fine. However, last week on a trip to Iceland I noticed that many pictures were showing up with a small circular blemish in the same position, regardless of what lens I was using. I'm attaching an example - see the little dot just to the left of center in the to part of the picture? I'm guessing that I must have a sensor issue, or could it be something between the sensor and the lens... or alternatively software related (as it doesn't always seem to show up). On an unrelated issue, I noticed that many autofocus images of glacial ice seemed out of focus. These were shots of small icebergs in a lagoon that were floating from 100-400 feet away from me. Is this a known issue? Any insights?

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09-02-2012, 11:12 PM	#2
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	dust on your sensor, get a blower. You can clone it out with post processing software.

09-03-2012, 02:45 AM	#3
baro-nite Loyal Site Supporter Join Date: Aug 2011 Location: North Carolina, USA Photos: Gallery \| Albums Posts: 5,295	Looks like dust all right. As to the icebergs and focus, ice isn't generally a very contrasty subject and AF may well have trouble latching on to it.

09-03-2012, 09:49 AM	#4
GeoJerry Veteran Member Join Date: Dec 2011 Location: Santa Barbara, CA Photos: Gallery Posts: 5,158 Original Poster	Thanks for the quick feedback. I suspected as much, but I didn't want to go into my camera's innards until I heard back from a few people who know more than I about the subject!

09-04-2012, 07:16 AM	#5
Stefanyshyn New Member Join Date: Aug 2012 Location: Calgary, Alberta, Canada Posts: 2	Not wanting to overlook the obvious, but do you have the automatic sensor cleaning option checked off, and have you tried using the cameras built in sensor cleaning function? Also, there was recall of K5's back January 2011 for water drops on the sensor. I don't think this is your problem but worth looking into (To PENTAX K-5 Digital SLR Camera Users \| PENTAX RICOH IMAGING)

09-07-2012, 10:42 PM	#6
GeoJerry Veteran Member Join Date: Dec 2011 Location: Santa Barbara, CA Photos: Gallery Posts: 5,158 Original Poster	Originally posted by Stefanyshyn Not wanting to overlook the obvious, but do you have the automatic sensor cleaning option checked off, and have you tried using the cameras built in sensor cleaning function? Also, there was recall of K5's back January 2011 for water drops on the sensor. I don't think this is your problem but worth looking into (To PENTAX K-5 Digital SLR Camera Users \| PENTAX RICOH IMAGING) Yes, I did try to use the sensor cleaning function but it was unable to dislodge this bit of dust. I do have the clean at startup option checked. I was able to get rid of the dust though with an air bulb blower. I was in a very dry windy are with lots of powder sized dust, that must have been it.