Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-13-2012, 09:11 PM   #1
Veteran Member
Buschmaster's Avatar

Join Date: Dec 2006
Location: Minnesota
Posts: 806
Oh God, what is this?!

So I've uploaded a full image, as well as a 100% crop, in the crop you should see two dots that shouldn't be there.

The one on the left is blue and more bright, then just above the C there is a more purpleish one...

What has happened to my beautiful beautiful camera? Just noticing these tonight, not noticing them on the pictures I took earlier today...

Attached Images
View Picture EXIF
PENTAX K20D  Photo 
View Picture EXIF
PENTAX K20D  Photo 
10-13-2012, 09:25 PM   #2
Loyal Site Supporter
paulh's Avatar

Join Date: Sep 2010
Location: DFW Texas
Photos: Gallery | Albums
Posts: 12,432
Hot pixels - very common, especially on older cameras. My *istD has about a half-dozen or so. I usually clone them out in pp. I think the K20 has a pixel-mapping function that allows you to deal with them. Someone more knowledgeable than me on the K20 can help you - or take a look in your manual.
10-13-2012, 09:25 PM   #3
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
Just a hot pixel, don't look that close and you'll never see them.
10-13-2012, 09:28 PM   #4
Pentaxian
jeffshaddix's Avatar

Join Date: Jun 2010
Location: Albuquerque, NM
Posts: 1,371
Hot pixels can come and go, just use your pixel mapping function. I had them occasionally on my K-7, which used the same sensor as your K20D.

10-13-2012, 09:29 PM   #5
Veteran Member
Buschmaster's Avatar

Join Date: Dec 2006
Location: Minnesota
Posts: 806
Original Poster
Is there any way to make them come and go (Particularly, GO) or not?

Thanks all. The reason I posted the second pic was to show how minor the problem is.
10-13-2012, 09:46 PM   #6
Pentaxian
Sagitta's Avatar

Join Date: Feb 2011
Location: Maine
Photos: Gallery
Posts: 2,912
I had a hot pixel pop up on my old Powershot. The ability to nuke the things on a Pentax almost makes the brand worthwhile alone. I think I have about a year and a half of hot pixel action going on my old Powershot images because the camera had no internal way of zapping them.
10-13-2012, 10:02 PM   #7
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
QuoteOriginally posted by Buschmaster Quote
Is there any way to make them come and go (Particularly, GO) or not?
ISO can affect it, you might notice more hot pixels at high ISO.
10-13-2012, 10:12 PM   #8
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 4,989
Lightroom and some other RAW converters will also automatically get rid of them on import. I've got them on my K10D (which has no pixel mapping), but never see them because LR gets rid of them.

10-13-2012, 10:27 PM   #9
Veteran Member
Buschmaster's Avatar

Join Date: Dec 2006
Location: Minnesota
Posts: 806
Original Poster
Awesome! Thanks all!
10-14-2012, 09:57 AM   #10
Veteran Member




Join Date: Nov 2009
Location: Iowa
Photos: Albums
Posts: 2,269
As I remember it, if you put the camera in manual mode and take a 30 second or longer exposure with the lens cap on, it remaps the pixels. I did that on a K100D once & it did the trick.
10-14-2012, 12:56 PM   #11
Veteran Member
Buschmaster's Avatar

Join Date: Dec 2006
Location: Minnesota
Posts: 806
Original Poster
I'll try that now!
10-14-2012, 04:07 PM   #12
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 4,989
QuoteOriginally posted by GibbyTheMole Quote
As I remember it, if you put the camera in manual mode and take a 30 second or longer exposure with the lens cap on, it remaps the pixels. I did that on a K100D once & it did the trick.
As a permanent fix even for shorter exposures? Are you sure you weren't just kicking the the noise reduction for long exposures that may have eliminated them from what was otherwise a dark frame for that single shot with the lens cap on? Neat trick if it works, but I'm skeptical...
10-14-2012, 05:34 PM   #13
Veteran Member




Join Date: Nov 2009
Location: Iowa
Photos: Albums
Posts: 2,269
QuoteOriginally posted by vonBaloney Quote
As a permanent fix even for shorter exposures? Are you sure you weren't just kicking the the noise reduction for long exposures that may have eliminated them from what was otherwise a dark frame for that single shot with the lens cap on? Neat trick if it works, but I'm skeptical...
Yep... And here's where I read about it. Worked for me, but I can't guarantee it'll work for others.
10-14-2012, 05:43 PM   #14
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 4,989
QuoteOriginally posted by GibbyTheMole Quote
Yep... And here's where I read about it. Worked for me, but I can't guarantee it'll work for others.
Cool, I'll give it a try on my K10D -- definitely has a few hot pixels now.

It isn't actually remapping them (which is a computer function of identifying the bad ones and averaging around them), just attempting to unstick them.

Last edited by vonBaloney; 10-14-2012 at 05:55 PM.
10-14-2012, 06:30 PM   #15
Veteran Member
alohadave's Avatar

Join Date: Jan 2008
Location: Quincy, MA
Photos: Gallery | Albums
Posts: 2,024
QuoteOriginally posted by vonBaloney Quote
Cool, I'll give it a try on my K10D -- definitely has a few hot pixels now.

It isn't actually remapping them (which is a computer function of identifying the bad ones and averaging around them), just attempting to unstick them.
There is a difference between a hot pixel and a stuck pixel.

Hot pixels tend to show up when the sensor heats up (like during long exposures). Generally when you take shorter exposures, or wait for the camera to rest, the hot pixels will go away. They'll also be in different places on different times (different days or after some time has passed).

If the exposure is long enough to kick in the LENR, it's not unsticking anything, it's just using dark frame subtraction to edit the spots out. The next time your camera turns on, the pixel is likely to have cleared on it's own.

A stuck pixel is one that is always on, and you may or may not see it all the time, depending on the exposure and what color is surrounding the pixel in various shots, and what level of detail is near that pixel.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, crop, dslr, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Streets With God's help .. Velja Post Your Photos! 3 04-30-2012 05:44 AM
Genesis 1 if there is no God... JohnBee General Talk 64 01-20-2012 08:24 PM
People Connecting with god yusuf Post Your Photos! 6 08-04-2011 06:05 AM
Oh god! Now what? slr_neophyte Troubleshooting and Beginner Help 9 06-01-2011 06:11 AM
a discussion on god... god i was bored.. Gooshin General Talk 9 02-11-2010 01:01 PM



All times are GMT -7. The time now is 12:49 AM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top