Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-05-2013, 04:31 PM   #1
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
K-5 only a few weeks old having lines

So, my Pentax K-5 shows what looks like scanner lines in low light shots. I just bought this a few weeks ago and was wondering if this is normal. I took the photo in color but changed it to black and white. I didn't have anything like this happen with my K-X and was wondering if i have a bad sensor. Any help would be nice.
View attached photos.

Attached Images
   
04-05-2013, 05:01 PM   #2
Veteran Member




Join Date: Aug 2011
Location: Niagara
Photos: Gallery | Albums
Posts: 792
New or used, serial number? Does it happen always, only this photo, only low light, EXIF data? We'll likely need more info.
04-05-2013, 05:10 PM   #3
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
Original Poster
The camera is new. It happens only in low light. ISO-6400, f/4, 1/40sec., -2exposure bias, focal length 28mm
04-05-2013, 05:13 PM   #4
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
Original Poster
Doesn't happen in good light

I don't see the artifact in better lighting at all.

Attached Images
 
04-05-2013, 05:23 PM - 1 Like   #5
Veteran Member
VisualDarkness's Avatar

Join Date: Nov 2011
Location: Uppsala, Sweden
Photos: Gallery
Posts: 4,441
Florescent lighting? That can cause interference due to cycling the light intensity and even color temperature at times.
Otherwise it's probably banding due to underexposure. Did you bring exposure up in post-processing? I can't recall seeing that kind of intensity of banding at only ISO6400 in a correctly exposed pic with the K-5, it looks almost like Canon banding.
04-05-2013, 05:29 PM   #6
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
Original Poster
I dig bring up the exposure in post a little just to make the lines that i was talking about more noticeable.
I did buy the extended warranty just in case anything went wrong. I have heard of things like this happening to sensors and basically was just wondering if this was a sign of worse things to come.
04-05-2013, 05:39 PM - 1 Like   #7
Site Supporter
vagrant10's Avatar

Join Date: May 2007
Location: portland
Photos: Albums
Posts: 1,361
have you had this situation happen on multiple sd cards? I''ve heard of cards starting to go bad doing this...

Hi f/ pdx btw
04-05-2013, 05:47 PM   #8
Veteran Member
VisualDarkness's Avatar

Join Date: Nov 2011
Location: Uppsala, Sweden
Photos: Gallery
Posts: 4,441
As the low ISO one doesn't show banding at all I'm pretty sure it's not SD card or something like that. Trying to push the exposure slightly when taking the shot as the -2 probably makes it much much worse, especially if you push it in PP. It should have less banding at the same exposure and ISO than you K10D, have you compared pics of the same exposure and same ISO taken with the cameras? Is it Jpeg or RAW?

04-05-2013, 05:51 PM   #9
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
Original Poster
The photo was taken in RAW. Other photos that night came out with the same lines.
04-05-2013, 06:11 PM   #10
Veteran Member
VisualDarkness's Avatar

Join Date: Nov 2011
Location: Uppsala, Sweden
Photos: Gallery
Posts: 4,441
Can you upload an original RAW file somewhere for people here to look at? I'm pretty sure it's the -2 exposure compensation in combination with brutal lighting that's the culprit in this case. Just upload it and people will check it out!
04-05-2013, 06:26 PM   #11
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
Original Poster
The forum won't let me post the PEF file. What it sounds like to me is that it's user error. That's fine by me because i am still new to the digital realm. I also have a KX that i have had for 2yrs but it still only has 10k shots after all that time. I will just be more aware of my settings in the future and watch for any odd artifacts like these lines.
As i am new to this forum i would like to thank all of you for your quick replies.
04-05-2013, 06:28 PM   #12
Site Supporter




Join Date: May 2012
Location: Adelaide
Photos: Gallery | Albums
Posts: 1,104
Underexposing -2EV using ISO6400 is loosely akin to shooting at ISO25000+, so I suspect you are really pushing the boundaries of what you can get out of the sample image. As suggested, try some correctly exposed ISO6400 images, checking with the histogram in image playback that the histogram graph is well centred and not bunched to the left. Let us know how those images work out once loaded to your pc.
04-05-2013, 06:31 PM - 1 Like   #13
Veteran Member
VisualDarkness's Avatar

Join Date: Nov 2011
Location: Uppsala, Sweden
Photos: Gallery
Posts: 4,441
Upload it to something like Skydrive if you still want people to look at it to be sure there's no issues, don't afraid of asking about problems as people are generally very very helpful here.
04-05-2013, 06:58 PM   #14
New Member




Join Date: Mar 2013
Location: Portland, Or.
Posts: 18
Original Poster
After trying to repeat the problem i didn't get anything that was like the first photo until i really ramped up the iso to 51200. This photo is the result of 51200. Lines are starting to show up. I know that nobody in their right mind would ever force an iso this high but this is purely for troubleshooting.
Attached Images
View Picture EXIF
PENTAX K-5  Photo 
04-05-2013, 07:13 PM   #15
Veteran Member
VisualDarkness's Avatar

Join Date: Nov 2011
Location: Uppsala, Sweden
Photos: Gallery
Posts: 4,441
At very very rare occasions I've used that high ISO.
It was very dark and I had to have a short shutter speed to freeze the young foxes as they weren't still for a second. So in this case is was something or nothing and I'm happy I got it at all as the poses is wonderful!



I had another one at ISO10000 when they were a tad calmer so I could get the shutter down to 1/100.



Both are PP'ed with different degrees of noise reduction and they are worth more to me than their technical quality. I shoot mostly up to ISO6400 when needed and some sports slightly higher (small pics on websites and daily newspapers allow this) and when absolutely needed ISO12800 often cleans up nicely for webviewing if exposed correctly.
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!
k-5, lines, pentax help, weeks
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Old Vivitar 80-200 from old Pentax K1000 on a new K-5 Jim Stewart Visitors' Center 3 02-13-2013 05:13 AM
For Sale - Sold: Pentax DA 18-135mm WR Lens-MINT-only few weeks old harleynitelite Sold Items 3 10-07-2012 03:29 PM
Misc A few faves from the last few weeks dermc Post Your Photos! 6 01-14-2011 09:12 AM
It's been a few weeks Here are a few for ya Petthefish Post Your Photos! 9 11-03-2007 10:41 PM
Only a few min. old Photo Tramp Post Your Photos! 12 08-07-2007 05:27 AM



All times are GMT -7. The time now is 04:59 AM. | 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