K-5 sensor problem

Babylon7 · 09-16-2012, 09:56 PM

Hi,

I am about to buy a used K-5 with a Tamron 70-300. The seller sent me a couple of sample shots and I noticed the photos have this particular color dot.

I have attached these 2 photos, the dots are circled (I think they're at the same position but the original photos were cropped so I'm not 100% sure).

Is it the problem with the sensor (stuck pixel) or is just the lens?

Thanks.

Attached Images

View Picture EXIF

vonBaloney · 09-16-2012, 09:57 PM

Probably a stuck pixel, and those will happen to a sensor over time no matter what. You use the "pixel mapping" feature to get rid of them.

Babylon7 · 09-16-2012, 10:03 PM

Thanks vonBaloney,

Is that a feature in the firmware? I'm not too familiar with newer models (my last one was K10D)...

vonBaloney · 09-16-2012, 10:21 PM

Originally posted by Babylon7

Thanks vonBaloney,

Is that a feature in the firmware? I'm not too familiar with newer models (my last one was K10D)...

Yeah, not sure if they happen on not on the K10D with its CCD sensor, but it is fairly common for a even a brand-new K-7 or K-5 to come with a stuck pixel or two (or anything with a CMOS sensor), and then every once in a while you'll get a new one. You just run "pixel mapping" off the menu and it gets rid of it. (What it does it mark those pixels to not be used in the future and it will average the pixels around it.) On an LCD monitor when the same thing happens, sometimes you can unstick them but don't know if you can on a camera. The easiest way to spot them (they aren't always a bright color) is to shoot a video and create a lot of motion -- just wave the camera around shooting a wall. (Shooting some video might be the strategy to try to unstick them before pixel mapping them, but I have no idea if that would work.) Playback the video on a TV and you can easily see anything not moving with the rest -- dirt on the sensor will show up as well as fixed spots.

Last edited by vonBaloney; 09-16-2012 at 10:30 PM.

rawr · 09-16-2012, 10:22 PM

Originally posted by Babylon7

Is that a feature in the firmware?

It's under the Setup menu in the K-5:
Setup Menu 4 > Pixel Mapping.

It should do the job.

Maybe you should ask the seller to do it before you buy the camera, then send you a test shot, just to confirm that it has indeed cleaned them up before buying the camera.

Babylon7 · 09-17-2012, 05:45 AM

Originally posted by vonBaloney

Yeah, not sure if they happen on not on the K10D with its CCD sensor, but it is fairly common for a even a brand-new K-7 or K-5 to come with a stuck pixel or two (or anything with a CMOS sensor), and then every once in a while you'll get a new one. You just run "pixel mapping" off the menu and it gets rid of it. (What it does it mark those pixels to not be used in the future and it will average the pixels around it.) On an LCD monitor when the same thing happens, sometimes you can unstick them but don't know if you can on a camera. The easiest way to spot them (they aren't always a bright color) is to shoot a video and create a lot of motion -- just wave the camera around shooting a wall. (Shooting some video might be the strategy to try to unstick them before pixel mapping them, but I have no idea if that would work.) Playback the video on a TV and you can easily see anything not moving with the rest -- dirt on the sensor will show up as well as fixed spots.

Thanks, I will the video shooting a try.

Babylon7 · 09-17-2012, 05:49 AM

Originally posted by rawr

It's under the Setup menu in the K-5:
Setup Menu 4 > Pixel Mapping.

It should do the job.

Maybe you should ask the seller to do it before you buy the camera, then send you a test shot, just to confirm that it has indeed cleaned them up before buying the camera.

The seller doesn't like to answer any of my questions with a straight answer, so I probably need to do it myself. The only reason I am buying it is because the offer is too good to be refused (I think there should be at least several months of warranty remaining).

vonBaloney · 09-17-2012, 07:32 AM

Originally posted by Babylon7

The seller doesn't like to answer any of my questions with a straight answer

Red flag.

Quote:

The only reason I am buying it is because the offer is too good to be refused.

And another. Be careful out there...

Babylon7 · 09-17-2012, 07:54 AM

Originally posted by vonBaloney

Red flag.

And another. Be careful out there...

Will let you know how it goes - but CAN$650 for the 10-month old body (8000 clicks) and Tamron 70-300 LD. Warranty not transferrable so this is a risk...

Babylon7 · 09-17-2012, 06:06 PM

Originally posted by vonBaloney

Red flag.

And another. Be careful out there...

Happy to report the camera is solid, pixel mapping cleared up the stuck pixels.

vonBaloney · 09-17-2012, 06:20 PM

Originally posted by Babylon7

Happy to report the camera is solid, pixel mapping cleared up the stuck pixels.

Cool. Check everything else...

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09-16-2012, 09:57 PM	#2
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Probably a stuck pixel, and those will happen to a sensor over time no matter what. You use the "pixel mapping" feature to get rid of them.

09-16-2012, 10:03 PM	#3
Babylon7 New Member Join Date: Sep 2012 Posts: 13 Original Poster	Thanks vonBaloney, Is that a feature in the firmware? I'm not too familiar with newer models (my last one was K10D)...

09-16-2012, 10:21 PM	#4
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by Babylon7 Thanks vonBaloney, Is that a feature in the firmware? I'm not too familiar with newer models (my last one was K10D)... Yeah, not sure if they happen on not on the K10D with its CCD sensor, but it is fairly common for a even a brand-new K-7 or K-5 to come with a stuck pixel or two (or anything with a CMOS sensor), and then every once in a while you'll get a new one. You just run "pixel mapping" off the menu and it gets rid of it. (What it does it mark those pixels to not be used in the future and it will average the pixels around it.) On an LCD monitor when the same thing happens, sometimes you can unstick them but don't know if you can on a camera. The easiest way to spot them (they aren't always a bright color) is to shoot a video and create a lot of motion -- just wave the camera around shooting a wall. (Shooting some video might be the strategy to try to unstick them before pixel mapping them, but I have no idea if that would work.) Playback the video on a TV and you can easily see anything not moving with the rest -- dirt on the sensor will show up as well as fixed spots. Last edited by vonBaloney; 09-16-2012 at 10:30 PM.

09-16-2012, 10:22 PM	#5
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Originally posted by Babylon7 Is that a feature in the firmware? It's under the Setup menu in the K-5: Setup Menu 4 > Pixel Mapping. It should do the job. Maybe you should ask the seller to do it before you buy the camera, then send you a test shot, just to confirm that it has indeed cleaned them up before buying the camera.

09-17-2012, 05:45 AM	#6
Babylon7 New Member Join Date: Sep 2012 Posts: 13 Original Poster	Originally posted by vonBaloney Yeah, not sure if they happen on not on the K10D with its CCD sensor, but it is fairly common for a even a brand-new K-7 or K-5 to come with a stuck pixel or two (or anything with a CMOS sensor), and then every once in a while you'll get a new one. You just run "pixel mapping" off the menu and it gets rid of it. (What it does it mark those pixels to not be used in the future and it will average the pixels around it.) On an LCD monitor when the same thing happens, sometimes you can unstick them but don't know if you can on a camera. The easiest way to spot them (they aren't always a bright color) is to shoot a video and create a lot of motion -- just wave the camera around shooting a wall. (Shooting some video might be the strategy to try to unstick them before pixel mapping them, but I have no idea if that would work.) Playback the video on a TV and you can easily see anything not moving with the rest -- dirt on the sensor will show up as well as fixed spots. Thanks, I will the video shooting a try.

09-17-2012, 05:49 AM	#7
Babylon7 New Member Join Date: Sep 2012 Posts: 13 Original Poster	Originally posted by rawr It's under the Setup menu in the K-5: Setup Menu 4 > Pixel Mapping. It should do the job. Maybe you should ask the seller to do it before you buy the camera, then send you a test shot, just to confirm that it has indeed cleaned them up before buying the camera. The seller doesn't like to answer any of my questions with a straight answer, so I probably need to do it myself. The only reason I am buying it is because the offer is too good to be refused (I think there should be at least several months of warranty remaining).

09-17-2012, 07:32 AM	#8
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by Babylon7 The seller doesn't like to answer any of my questions with a straight answer Red flag. Quote: The only reason I am buying it is because the offer is too good to be refused. And another. Be careful out there...

09-17-2012, 07:54 AM	#9
Babylon7 New Member Join Date: Sep 2012 Posts: 13 Original Poster	Originally posted by vonBaloney Red flag. And another. Be careful out there... Will let you know how it goes - but CAN$650 for the 10-month old body (8000 clicks) and Tamron 70-300 LD. Warranty not transferrable so this is a risk...

09-17-2012, 06:06 PM	#10
Babylon7 New Member Join Date: Sep 2012 Posts: 13 Original Poster	Originally posted by vonBaloney Red flag. And another. Be careful out there... Happy to report the camera is solid, pixel mapping cleared up the stuck pixels.

09-17-2012, 06:20 PM	#11
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by Babylon7 Happy to report the camera is solid, pixel mapping cleared up the stuck pixels. Cool. Check everything else...