Advice: Long exposure on K-5

JFHY · 05-30-2012, 09:44 PM

Hi,

I need some input from gurus here. I understand hot pixel are inevitable when it comes to long exposures, but what level of it is consider normal? I've started to take long exposures (~5 mins iso400-800) on my k-5 for my study project. I noticed that there are hot pixel which are normal but what gets me wondering/worrying is that aside from the scattered hot pixels, there is an obvious cluster of hot ('hotter' if i may say) pixels in the center region of the photo.

Image was taken with the lens cap and viewfinder cover on at iso800 for 3 mins. Cluster shown by the circle.

Image taken at iso400 for 6mins.

My question is, is the cluster normal or is it something i should send to have it looked at (still under warranty)? anyone could share their raw long exposure shots? thanks

Last edited by JFHY; 05-30-2012 at 11:58 PM.

Pentaxtic · 05-30-2012, 11:23 PM

Can't see the images of the hot pixels.

JFHY · 05-30-2012, 11:58 PM

Originally posted by Pentaxtic

Can't see the images of the hot pixels.

fixed. Thanks

Andrew Lang · 05-31-2012, 07:52 AM

i'd try the pixel correction tool in the menu, if it still persists and it interferes with your photography, give the repair shop a call and send them the files, ask them if that's within tolerances and see if they will do something about it

**Odinz** · 06-04-2012, 01:46 PM

Wow, I've seen hot pixels before, but never clumped like that. Is that second image a greatly enlarged crop of the first one? If not, and it fills that whole center portion of the sensor you may have an issue. Usually the hot pixels will appear as a random pattern of varying intensity spots like the night sky across most of the image. Sometimes you'll get a group of a few like sized pixels, or in long enough exposures hot pixels will spill over into the pixels around them. Is your K5 an early model and could this be related to the original sensor 'staining' issue?

05-30-2012, 09:44 PM	#1
JFHY New Member Join Date: May 2012 Posts: 2	Advice: Long exposure on K-5 Hi, I need some input from gurus here. I understand hot pixel are inevitable when it comes to long exposures, but what level of it is consider normal? I've started to take long exposures (~5 mins iso400-800) on my k-5 for my study project. I noticed that there are hot pixel which are normal but what gets me wondering/worrying is that aside from the scattered hot pixels, there is an obvious cluster of hot ('hotter' if i may say) pixels in the center region of the photo. Image was taken with the lens cap and viewfinder cover on at iso800 for 3 mins. Cluster shown by the circle. Image taken at iso400 for 6mins. My question is, is the cluster normal or is it something i should send to have it looked at (still under warranty)? anyone could share their raw long exposure shots? thanks Last edited by JFHY; 05-30-2012 at 11:58 PM.

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05-30-2012, 11:23 PM	#2
Pentaxtic Veteran Member Join Date: Nov 2007 Location: Vancouver Photos: Gallery Posts: 417	Can't see the images of the hot pixels.

05-30-2012, 11:58 PM	#3
JFHY New Member Join Date: May 2012 Posts: 2 Original Poster	Originally posted by Pentaxtic Can't see the images of the hot pixels. fixed. Thanks

05-31-2012, 07:52 AM	#4
Andrew Lang Senior Member Join Date: Oct 2009 Location: Thunder Bay Photos: Gallery \| Albums Posts: 184	i'd try the pixel correction tool in the menu, if it still persists and it interferes with your photography, give the repair shop a call and send them the files, ask them if that's within tolerances and see if they will do something about it

06-04-2012, 01:46 PM	#5
Odinz Loyal Site Supporter Join Date: Jan 2008 Location: Virginia, USA Photos: Albums Posts: 258	Wow, I've seen hot pixels before, but never clumped like that. Is that second image a greatly enlarged crop of the first one? If not, and it fills that whole center portion of the sensor you may have an issue. Usually the hot pixels will appear as a random pattern of varying intensity spots like the night sky across most of the image. Sometimes you'll get a group of a few like sized pixels, or in long enough exposures hot pixels will spill over into the pixels around them. Is your K5 an early model and could this be related to the original sensor 'staining' issue?

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