Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-12-2017, 09:31 AM   #1
New Member




Join Date: Dec 2017
Posts: 3
Out of focus if taken with viewfinder, in focus if taken with live view

Hey! I bought a Pentax K-S2 a year ago and never had any trouble with it. Unfortunately, since a week or so, everytime I take an image with my 50mm f1.8 lens via the viewfinder the results are out of focus. In the viewfinder, it shows the red dot and there is a beep and everything seems sharp, but when I view the actual shot it is always slightly out of focus.

However all the shots taken with live view are sharp.


At first, I thought this was a problem with the lens-body communication pins, but after taking some shots with my 18-55mm the problem remained. So there is something wrong with my camera, but I don't know why (I never dropped it), what is causing the problem and how to solve this issue. I will post some photos tomorrow to show you how bad this is, especially since I am an amateur wildlife photographer and I need a fast and accurate AF, so I don't shoot in live view very often.
Please tell me if you know this problem, know what causes this issue or know how to fix it 😀😗

12-12-2017, 10:05 AM - 1 Like   #2
Junior Member




Join Date: Nov 2012
Photos: Albums
Posts: 35
Maybe dirt/dust in the AF sensor or need for AF fine adjustment?
12-12-2017, 10:19 AM - 1 Like   #3
Loyal Site Supporter
Loyal Site Supporter




Join Date: May 2016
Location: East Coast
Posts: 874
Just curious, but if you put it manual focus with the viewfinder, ignoring what the camera thinks, and just focus for what looks sharp to you, is it?
12-12-2017, 10:38 AM - 2 Likes   #4
Pentaxian
microlight's Avatar

Join Date: Sep 2011
Location: Hampshire, UK
Posts: 579
Did you initially set up the fine focus adjustment for the kit lens when you got it a year ago? Have you changed any of the fine focus adjustments recently? It sounds like classic back or front focusing, especially if live view is sharp.

12-12-2017, 10:56 AM - 1 Like   #5
Veteran Member




Join Date: Aug 2014
Location: Italia
Photos: Albums
Posts: 326
Did you accidentally adjusted the diopters of the VF? Just curious: are the focus errors Always the same way (I mean Always backfocus or frontfocus or erratic)?
12-12-2017, 11:05 AM - 1 Like   #6
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 11,189
a) make sure viewfinder diopter is not off
b) make sure AF adjustment is not wrong. Some cameras only have global lens adjustment, some have per-lens adjustments. Start with it off. There are various threads on this forum about AF fine adjustment and how to do it
c) have you fiddled with the focusing screen? If you installed a new focusing screen without shims it might cause some focusing errors
d) which lens are you using? Some lenses have focus breathing, where the focus will shift depending on aperture. This means you can focus correctly at wide open aperture, but the focus will shift for the photo because another aperture is chosen for that photo. Reading the OP, I guess this is probably not the problem here
e) Make sure you are not using filters. Some filters can affect AF, particularly linear polarizers

Also, maybe you want to clean the camera mount and check for damage, just to make sure that is not the problem. Another thing you can do is update the camera firmware to the latest one (lots of threads and even youtube video about how to do this), as it can sometimes solve little hiccups. You can also do one of the Reset options to fully reset all camera settings to default.

The idea about dust on AF sensor is interesting. You can use rocket blower to try to fix that, or you can take camera to a shop for cleaning and tell them about the problem. They should know what tests to run to diagnose the issue
12-12-2017, 11:27 AM   #7
Site Supporter
Site Supporter




Join Date: May 2016
Photos: Albums
Posts: 975
Did you drop the camera?
12-12-2017, 04:02 PM - 1 Like   #8
Loyal Site Supporter
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 10,547
Try this, Alex ...

Fixing Front and Back Focus - Introduction - In-Depth Articles

12-12-2017, 07:13 PM - 1 Like   #9
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 9,182
QuoteOriginally posted by Na Horuk Quote
a) make sure viewfinder diopter is not off
To check this: focus the lens at infinity and look through the viewfinder, if the image on the focus screen is blurry your dioptre setting is wrong - adjust it until the image is sharp.

QuoteOriginally posted by Na Horuk Quote
Make sure you are not using filters. Some filters can affect AF, particularly linear polarizers
The Linear polarizer myth has been debunked since no current DSLR uses beamsplitters anywhere in the optical path of the AF system.

Last edited by Digitalis; 12-12-2017 at 07:21 PM.
12-13-2017, 07:43 AM   #10
New Member




Join Date: Dec 2017
Posts: 3
Original Poster
Thank you all for your advice, I really appreciate your help

Thanks to you I know that I have a back focussing issue with my ks2. My Phase Autofocus doesn't work properly so I have to do a fine adjustment. I will tell you if it works or not
12-13-2017, 07:59 AM - 2 Likes   #11
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 11,189
QuoteOriginally posted by Alexvc Quote
Thanks to you I know that I have a back focussing issue with my ks2. My Phase Autofocus doesn't work properly so I have to do a fine adjustment. I will tell you if it works or not
Yes, this is a common issue with many digital cameras, that's why they have the adjust function. Keep in mind that its not just a camera issue, but its a lens-camera relationship. Some people had two copies of the same lens on the exact same camera, and one was misfocusing, while the other one wasn't. The problem is that sometimes the lens and the camera are at opposite tolerances.
You might find that many lenses will not have front or back focusing on your camera, but some might. Good luck!
12-14-2017, 07:42 AM - 1 Like   #12
New Member




Join Date: Dec 2017
Posts: 3
Original Poster
Thank you! In my case the back focussing problem was with my 3 lenses (50mm1.8, 18-55mm and 50-300mm) and I had to do a fine adjustment of +8 for each lens, but now the autofocus works absolutely fine with all my lenses so all of you guys really helped my! Thanks a lot for your answers!
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, focus, issue, pentax help, photography, shots, troubleshooting, view, viewfinder
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mid shoot last night. Auto focus not working in viewfinder but is in live view Lurch1066 Troubleshooting and Beginner Help 17 07-31-2017 08:01 AM
live view noise and smc dfa 100mm f2.8 macro lens not focusing in live view tommygunn84 Troubleshooting and Beginner Help 7 11-24-2016 08:59 PM
View lens length in viewfinder or live view? Oakland Rob Pentax K-3 4 10-23-2016 05:19 AM
K-50 Live View vs Viewfinder (Viewfinder photos Under exposed) jackloganbill Pentax K-30 & K-50 11 06-10-2016 08:01 AM
Typical live view humming, when not in live view. lightsource Pentax K-1 8 05-05-2016 02:20 AM



All times are GMT -7. The time now is 12:33 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