Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-20-2014, 11:52 AM   #1
Inactive Account




Join Date: Nov 2014
Posts: 13
Left side of shot blury

For some reason, the left hand side of my pictures are blurry. Anyone know how to fix this?



12-20-2014, 12:01 PM   #2
Pentaxian




Join Date: Jun 2011
Location: NJ
Photos: Gallery
Posts: 4,882
Which lens? It looks like the lens may be de-centered.
12-20-2014, 12:07 PM   #3
Veteran Member




Join Date: Jul 2009
Location: London
Posts: 889
Any other shots you could post please? Right side looks equally oof to me.

A good test is to mount the camera on a tripod at 90 degrees to a brick wall, i.e. so it's squarely in front of it, then take some shots at varying apertures using LV to focus.
12-20-2014, 12:44 PM   #4
Pentaxian




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,181
Looks like a lens problem to me too. I had this on my Olympus XZ-1 under warranty - I sent it in for repair, and naturally it came back with the problem on the other side!



But actually it came back better - it was previously much more out of focus on the L than it is on the R now. It's now close enough that it isn't really a problem any more. I think the fast aperture of that lens (f/1.8-2.5) in a compact camera makes it much more sensitive to proper adjustment than a typical compact consumer lens.

BTW, what camera/lens were you using?

12-20-2014, 01:15 PM   #5
Inactive Account




Join Date: Nov 2014
Posts: 13
Original Poster
I am using a K3 with a DA 55-300mm F4-5.8 ED WR.
12-20-2014, 01:44 PM   #6
Pentaxian




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,181
QuoteOriginally posted by SonOfMerope Quote
I am using a K3 with a DA 55-300mm F4-5.8 ED WR.
You should send it in. I imagine it's still under warranty. I presume it's the HD model (I don't think they made a WR L model, did they?). QC may not be as good as it ought to - they should be able to adjust it.

- Son of Sim
12-20-2014, 06:31 PM   #7
Forum Member




Join Date: May 2012
Posts: 87
The only way to test a lens for being de-centered is a controlled scene, such as a brick wall (as a previous poster has suggested).

1) The scene must have an identical lighting source of the same temperature.
2) The aperture must be set at a reasonable value (about midway between minimum vignetting and minimum diffraction). You can use the values at Photozone.de for this lens.

I use f/8-f/10 on the DA 55-300 and focus on a brick wall at about 100' with the anti-shake off and the camera on a tripod. I apply lens correction both ways until the center is as sharp as possible.

I have rarely found a lens to be de-centered unless it has been physically damaged.

As for the image posted, it is hard to judge, but at 100% view the landing gear and shade lines appear equally sharp on both planes. Contrast appears weaker on the left side.
12-21-2014, 01:13 AM   #8
Pentaxian




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,181
QuoteOriginally posted by Hamiltom Quote
The only way to test a lens for being de-centered is a controlled scene, such as a brick wall (as a previous poster has suggested).
Nonsense. When it keeps coming up in your shots on the same side, you know you have a problem. Both sides of the frame are at (or very near) infinity. If you pay attention to what you're looking at, and scrutinize it a bit, it's fairly easy to determine when the lens needs to be sent in for repair. It's irrelevant whether it's technically de-centered (or something that merely "looks just like it") unless you're the actual repairman. Both the foreground and background are more out of focus on the left, and it can't be attributed to motion blur. So unless it's an unusual camera problem (e.g. sensor alignment) that's affecting all lenses, the lens needs to be sent in.


Last edited by DSims; 12-21-2014 at 01:23 AM.
12-21-2014, 07:00 AM   #9
Forum Member




Join Date: May 2012
Posts: 87
If you send the lens in, they will test it under in a controlled situation to evaluate and diagnose the problem. If it meets specifications, they will send it back to you untouched. In the meantime, you could have done a more scientific analysis of the problem and saved yourself the problem and expense of returning the lens.

Looking at a picture with a mixed scene and lighting, without knowing the EXIF data and whether or not a tripod or a filter was used is not very scientific.

You have opinions stating this image appears OK and others that say the left side is out of focus.

My advice is to do more testing. Here is a link to a sample chart and the methodology.

lens chart

There are many other charts available on the web.
12-21-2014, 09:34 AM   #10
Inactive Account




Join Date: Nov 2014
Posts: 13
Original Poster
How can I be sure it's the lens and not the camera itself? Or is this a specific problem that can only relate to the lens being decentered?
12-21-2014, 05:20 PM   #11
Forum Member




Join Date: May 2012
Posts: 87
If the sensor is misaligned, ALL lenses will be out of focus on the same side. If one lens achieves even focus, then the sensor is eliminated as the cause.
12-24-2014, 08:37 AM   #12
Pentaxian




Join Date: Apr 2007
Location: Oklahoma USA
Posts: 1,503
With a zoom lens like the OP has, it's important to test at a wide range of focal lengths. Centering can be ok at some focal lengths, but way off at others. Also check at both close and distant focus settings. Use manual focus so there is no question about what AF might be focusing on. I've found it helpful to focus on an object in the center of the frame, say a street sign (or, for closer distances, a test chart.) Then, with manual focus and exposure set, move the (tripod-mounted) camera so the sign is in each corner of the frame. Obviously you have to be careful not to touch the lens during the process, so focus remains identical.
12-24-2014, 10:18 AM   #13
Pentaxian




Join Date: Sep 2009
Location: Southern California
Photos: Gallery | Albums
Posts: 3,181
QuoteOriginally posted by tibbitts Quote
With a zoom lens like the OP has, it's important to test at a wide range of focal lengths. Centering can be ok at some focal lengths, but way off at others. Also check at both close and distant focus settings.
Very good point.


I do believe it's important for infinity focus to be good at all focal lengths - even if you don't focus at infinity very often. And this appears to be the problem here - though I'm not sure if it's only at certain focal lengths, or at all of them.
12-25-2014, 01:43 AM   #14
Senior Member
screwdriver222's Avatar

Join Date: Oct 2011
Location: Plymouth
Photos: Gallery | Albums
Posts: 134
I bought a DA 55-300 a couple of years back that was de-centred, returned it to Amazon and got a replacement. I tested it indoors in natural light mounted on a tripod and took pictures of a newspaper page taped to a wall, I made sure the camera was absolutely square to the wall. Tested at different aperatures and focal lengths. It was very obvious, with the text unreadable on one side.

Jeff
12-27-2014, 11:42 AM   #15
Inactive Account




Join Date: Nov 2014
Posts: 13
Original Poster
Thanks for the advice guys. I got a replacement from Amazon and it seems to be working fine.
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, pentax help, photography, troubleshooting
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-2000 Green Hue on left side of images KenShutter Troubleshooting and Beginner Help 16 10-10-2014 12:19 PM
645n lever on left side? tvrrproto48 Pentax Medium Format 7 02-09-2013 03:59 PM
HELP purple streaked lines on left side of pictures K20D artisansforafrica Pentax DSLR Discussion 6 08-03-2011 12:35 AM
SMC Pentax-A f/2.8 photos blurry on left side Designosophy Troubleshooting and Beginner Help 10 01-08-2011 08:27 AM
Left side of frame out of focus? K10D senojjj Pentax DSLR Discussion 5 09-29-2010 06:13 PM



All times are GMT -7. The time now is 08:43 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