Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-26-2010, 12:14 AM   #1
Forum Member




Join Date: Jan 2010
Location: California
Photos: Albums
Posts: 53
Long exposure leaves blue and red dots?

I was messing around with my camera tonight and took lots of long exposure shots (was playing around with an LED in front of it) and noticed that in many of the shots I have blue, red, and green dots in the EXACT same spot in multiple pictures. Camera was tripod mounted. Exposures were anywhere from 15-30 seconds each. I have never seen this before on any of my other cameras. What is it and how do I prevent it?

Attached is a picture of it. Hopefully you can see it even tho the picture quality has been downgraded with the upload. It's much brighter on the original.

Attached Images
 
02-26-2010, 12:32 AM   #2
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,484
Dead or hot pixels. Run the Pixel mapping routine. Should take care of it.

02-26-2010, 12:57 AM   #3
Veteran Member
LensScribe's Avatar

Join Date: Jan 2009
Location: Johannesburg, South Africa
Photos: Gallery
Posts: 316
Also, were the shots RAW or JPEG? I ask because when I do long exposures I usually shoot RAW, and until they're processed, they're always covered in the spots of which you speak. They vanish once I've run it through CameraRaw or similar.
02-26-2010, 02:13 PM   #4
Forum Member




Join Date: Jan 2010
Location: California
Photos: Albums
Posts: 53
Original Poster
These were shot in RAW. I imported them into Aperture 3 and that is where I saw them. Thanks for the replies and suggestions.

02-26-2010, 04:44 PM   #5
Veteran Member




Join Date: Apr 2009
Location: New York
Posts: 328
Also, make sure that "long exposure NR" is on in the config menu. I know it has that in the K200 and K20 so I doubt got rid of it on the K7
02-26-2010, 06:46 PM   #6
Veteran Member
wlachan's Avatar

Join Date: Sep 2006
Location: Canada
Photos: Albums
Posts: 2,626
Those are hot pixels which actually present at any ISO, but more obvious as the ISO gets higher. I don't know about other brands, but hot pixels are rather common with Pentax DSLRs. If you shoot RAW, most converters will remove them automatically.
02-26-2010, 07:15 PM   #7
New Member




Join Date: Feb 2010
Location: Colorado
Posts: 20
I've noticed some in my long exposures as well. Not quite as many as yours though . . .
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, dslr, exposure, photography, picture, shots
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What are those red dots? sajah Troubleshooting and Beginner Help 20 04-13-2009 11:20 PM
Blood red leaves near Loch Lomond brkl Post Your Photos! 7 03-22-2009 10:50 AM
Manual focusing using red AF confirmation dots? shuttervox Photographic Technique 17 02-14-2009 11:51 PM
Red and Blue dots? bwield Pentax DSLR Discussion 6 08-05-2008 01:51 PM
What are these red marks in the leaves, K10D? WildSioux Photographic Technique 29 06-23-2007 12:35 PM



All times are GMT -7. The time now is 03:05 PM. | See also: NikonForums.com, CanonForums.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