K-5, what are these spots?

mikknu · 09-14-2011, 11:51 AM

Hi

Recently, I was out taking pictures with long exposure, by night in the city. After, I've noticed some bright spots on the pictures (red and blue one below). Can anyone tell me what is causing them?
I've had a faulty K-5 replaced before (not because of this though), so I just want to be sure there isn't something wrong with this one. Could it be dirt on the lens?

This is just a crop of the real picture, just wanted to state the obvious

Adam · 09-14-2011, 11:53 AM

Those are hot pixels, Unless this is a 100% crop, then they look awfully big! Try using pixel mapping to suppress them.

mikknu · 09-14-2011, 12:14 PM

Originally posted by Adam

Those are hot pixels, Unless this is a 100% crop, then they look awfully big! Try using pixel mapping to suppress them.

You caught me there, it is a 100% crop.
This is the original picture:

What is pixel mapping, sounds familiar?

Rupert · 09-14-2011, 12:19 PM

I have a question....saw a couple of hot ones a while back, then they were gone. Can they disappear on their own? I have never run any pixel mapping. Never really been a problem, but I am curious?
Regards!

Gimbal · 09-14-2011, 01:23 PM

Many (most?) programs handling raw files remove hot pixels auto-magically when opening the files. That is probably why most people never see them.

JeffJS · 09-14-2011, 02:08 PM

Originally posted by mikknu

You caught me there, it is a 100% crop.
This is the original picture:

What is pixel mapping, sounds familiar?

Pixel mapping is a routine built into the camera (in the Setup Menu 4 at the top). It will find and mask them out or turn them off, not sure which. I had a couple on my K7 that I could actually see on the rear LCD. Mapped them out, never saw them again.

KungPOW · 09-14-2011, 05:26 PM

All cameras have hot pixels.

Most RAW converters will map them out.

Long exposures are more prone to them then short exposures.

They can appear to come and go and I can't expain that one.

cali92rs · 09-14-2011, 05:26 PM

Hot pixels or not, thats a real cool pic IMHO. Love the colors

mikknu · 09-14-2011, 10:33 PM

Thanks a bunch guys, great feedback. Now I know it's common, it wont bother me.

Originally posted by cali92rs

Hot pixels or not, thats a real cool pic IMHO. Love the colors

Thanks man, appreciate it

09-14-2011, 11:51 AM	#1
mikknu Forum Member Join Date: Dec 2010 Location: Silkeborg, Denmark Posts: 82	K-5, what are these spots? Hi Recently, I was out taking pictures with long exposure, by night in the city. After, I've noticed some bright spots on the pictures (red and blue one below). Can anyone tell me what is causing them? I've had a faulty K-5 replaced before (not because of this though), so I just want to be sure there isn't something wrong with this one. Could it be dirt on the lens? This is just a crop of the real picture, just wanted to state the obvious

09-14-2011, 11:53 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Those are hot pixels, Unless this is a 100% crop, then they look awfully big! Try using pixel mapping to suppress them. 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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09-14-2011, 12:14 PM	#3
mikknu Forum Member Join Date: Dec 2010 Location: Silkeborg, Denmark Posts: 82 Original Poster	Originally posted by Adam Those are hot pixels, Unless this is a 100% crop, then they look awfully big! Try using pixel mapping to suppress them. You caught me there, it is a 100% crop. This is the original picture: What is pixel mapping, sounds familiar?

09-14-2011, 12:19 PM	#4
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	I have a question....saw a couple of hot ones a while back, then they were gone. Can they disappear on their own? I have never run any pixel mapping. Never really been a problem, but I am curious? Regards!

09-14-2011, 01:23 PM	#5
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	Many (most?) programs handling raw files remove hot pixels auto-magically when opening the files. That is probably why most people never see them.

09-14-2011, 02:08 PM	#6
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Originally posted by mikknu You caught me there, it is a 100% crop. This is the original picture: What is pixel mapping, sounds familiar? Pixel mapping is a routine built into the camera (in the Setup Menu 4 at the top). It will find and mask them out or turn them off, not sure which. I had a couple on my K7 that I could actually see on the rear LCD. Mapped them out, never saw them again.

09-14-2011, 05:26 PM	#7
KungPOW Veteran Member Join Date: Nov 2007 Location: Vancouver, Canada Photos: Gallery Posts: 1,699	All cameras have hot pixels. Most RAW converters will map them out. Long exposures are more prone to them then short exposures. They can appear to come and go and I can't expain that one.

09-14-2011, 05:26 PM	#8
cali92rs Veteran Member Join Date: May 2011 Location: Long Beach, CA Posts: 3,354	Hot pixels or not, thats a real cool pic IMHO. Love the colors

09-14-2011, 10:33 PM	#9
mikknu Forum Member Join Date: Dec 2010 Location: Silkeborg, Denmark Posts: 82 Original Poster	Thanks a bunch guys, great feedback. Now I know it's common, it wont bother me. Originally posted by cali92rs Hot pixels or not, thats a real cool pic IMHO. Love the colors Thanks man, appreciate it

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