Does anyone have K3 focus issues?

Alnjpn · 02-15-2019, 08:18 PM

Hi all. The Auto Focus on my K3 seems very unreliable. There are no problems with live view where it is accurate. However, when I use the viewfinder I am getting a lot of back focus. This is with ALL my lenses. I have tried cleaning the contacts and the mirror but this has not rectified he issue. I have tried fine tuning the lenses but the focus issue seems to be random. It does hit focus occasionally but more than often does not. I don't remember my K30 being so bad. Is this a K3 thing? Is it worth upgrading to the KP to solve the issue? Do other DSLR brands suffer from the same issues when using the view finder to focus? Thanks.

Last edited by Alnjpn; 02-15-2019 at 08:40 PM.

MarkJerling · 02-15-2019, 09:00 PM

Originally posted by Alnjpn

Hi all. The Auto Focus on my K3 seems very unreliable. There are no problems with live view where it is accurate. However, when I use the viewfinder I am getting a lot of back focus. This is with ALL my lenses. I have tried cleaning the contacts and the mirror but this has not rectified he issue. I have tried fine tuning the lenses but the focus issue seems to be random. It does hit focus occasionally but more than often does not. I don't remember my K30 being so bad. Is this a K3 thing? Is it worth upgrading to the KP to solve the issue? Do other DSLR brands suffer from the same issues when using the view finder to focus? Thanks.

I'd suggest you may want to take some test shots and post those photos with the EXIF information intact. There should be no reason you can't focus as well with your K3 as with your K30, unless the camera has a fault.

**UncleVanya** · 02-15-2019, 09:16 PM

Have you cleaned the autofocus sensor under the mirror?

Alnjpn · 02-15-2019, 09:19 PM

Thanks. Unfortunately, I don't have any attachment space left on here. I have tested the camera many times with many lenses. Focus accuracy through live view is good, but very often missing focus when using the view finder. This is with the same settings. I am going to try cleaning the mirror again to see if that solves it. No I haven't tried the af sensor. How do I clean that?

stevebrot · 02-15-2019, 09:39 PM

Originally posted by Alnjpn

Unfortunately, I don't have any attachment space left on here.

Do you have Google Drive or Dropbox for simple download? Another alternative is to remote host on a photosharing site such as Flickr?

Steve

**UncleVanya** · 02-15-2019, 10:40 PM

This may help: Dirty autofocus sensor - PentaxForums.com

MarkJerling · 02-15-2019, 10:54 PM

Originally posted by Alnjpn

Thanks. Unfortunately, I don't have any attachment space left on here.

To post photos hosted elsewhere, simply place the web address of that image between [IMG] and [/IMG] and your image will display here.

hcc · 02-15-2019, 11:00 PM - **1 Like**

You received already a lot very good advice IMHO.

Having a K-3 myself, and having done the mistake once: could it be that the diopter adjustment dial (of your K-3 optical viewfinder) needs to be checked and adjusted?

I might be completely wrong, but ...... might be worth a quick check,

Alnjpn · 02-15-2019, 11:01 PM

Thanks. I will post some pics later. I have dodgy eyes and have adjusted the viewfinder. reading around it seems as though it might just be that all the lenses need microadjustment. I will try that again too.

Adam · 02-16-2019, 12:05 AM

Looks like you also have plenty of album space and gallery space if needed.

**Crooski** · 02-16-2019, 12:01 PM

Clean the autofocus sensor, under the mirror Not the mirror itself !

**Madaboutpix** · 02-16-2019, 12:10 PM

Originally posted by Alnjpn

Is this (unreliable PD-AF) a K3 thing?

Er, from my experience it isn't. Coming from a K-7, I'd say, if anything, my K-3 is focusing faster and more decisively, particularly in low light (including situations where the K-7 wouldn't have been able to obtain focus at all). As far as focus accuracy is concerned, under good conditions, both are pretty spot-on, though they struggle, at varying degrees, with sophisticated tracking (haven't been able to test the PLM 55-300 yet, which is K-3 compatible and might offer some improvement). And although I haven't done any serious tests, in four and a half years of use, with a fair range of lenses, I've never felt a need to fine-tune my K-3 for front- or back-focus issues.

Therefore, my informal guess would be your issues are either due to sample variation or (perhaps more likely) dirt on the AF sensor.

Alnjpn · 02-26-2019, 07:50 PM

Thanks for the feedback and sorry for the delay in getting back. I have been through and micro-adjusted all my lenses. This appears to have solved the issue for now. I haven't used them all in the field yet but with the ones I have, the focus is more reliable. Here are the adjustments:

DA21 f3.2 +9
DA35 f2.4 +6
DA40 XS +5
DA50 f1.8 +4
DAL 55-300 +3

Sigma 17-50 None

Sigma 10-20 None

Interestingly the adjustments get less as the focal length gets shorter - not sure why would that be.

Thanks again

02-15-2019, 08:18 PM	#1
Alnjpn Senior Member Join Date: May 2015 Location: Osaka Posts: 158	Does anyone have K3 focus issues? Hi all. The Auto Focus on my K3 seems very unreliable. There are no problems with live view where it is accurate. However, when I use the viewfinder I am getting a lot of back focus. This is with ALL my lenses. I have tried cleaning the contacts and the mirror but this has not rectified he issue. I have tried fine tuning the lenses but the focus issue seems to be random. It does hit focus occasionally but more than often does not. I don't remember my K30 being so bad. Is this a K3 thing? Is it worth upgrading to the KP to solve the issue? Do other DSLR brands suffer from the same issues when using the view finder to focus? Thanks. Last edited by Alnjpn; 02-15-2019 at 08:40 PM.

02-16-2019, 12:05 AM	#10
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Looks like you also have plenty of album space and gallery space if needed. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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02-15-2019, 09:00 PM	#2
MarkJerling Moderator Site Supporter Join Date: May 2012 Location: Wairarapa, New Zealand Photos: Gallery \| Albums Posts: 20,403	Originally posted by Alnjpn Hi all. The Auto Focus on my K3 seems very unreliable. There are no problems with live view where it is accurate. However, when I use the viewfinder I am getting a lot of back focus. This is with ALL my lenses. I have tried cleaning the contacts and the mirror but this has not rectified he issue. I have tried fine tuning the lenses but the focus issue seems to be random. It does hit focus occasionally but more than often does not. I don't remember my K30 being so bad. Is this a K3 thing? Is it worth upgrading to the KP to solve the issue? Do other DSLR brands suffer from the same issues when using the view finder to focus? Thanks. I'd suggest you may want to take some test shots and post those photos with the EXIF information intact. There should be no reason you can't focus as well with your K3 as with your K30, unless the camera has a fault.

02-15-2019, 09:16 PM	#3
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	Have you cleaned the autofocus sensor under the mirror?

02-15-2019, 09:19 PM	#4
Alnjpn Senior Member Join Date: May 2015 Location: Osaka Posts: 158 Original Poster	Thanks. Unfortunately, I don't have any attachment space left on here. I have tested the camera many times with many lenses. Focus accuracy through live view is good, but very often missing focus when using the view finder. This is with the same settings. I am going to try cleaning the mirror again to see if that solves it. No I haven't tried the af sensor. How do I clean that?

02-15-2019, 09:39 PM	#5
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Alnjpn Unfortunately, I don't have any attachment space left on here. Do you have Google Drive or Dropbox for simple download? Another alternative is to remote host on a photosharing site such as Flickr? Steve

02-15-2019, 10:40 PM	#6
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	This may help: Dirty autofocus sensor - PentaxForums.com

02-15-2019, 10:54 PM	#7
MarkJerling Moderator Site Supporter Join Date: May 2012 Location: Wairarapa, New Zealand Photos: Gallery \| Albums Posts: 20,403	Originally posted by Alnjpn Thanks. Unfortunately, I don't have any attachment space left on here. To post photos hosted elsewhere, simply place the web address of that image between [IMG] and [/IMG] and your image will display here.

02-15-2019, 11:00 PM - 1 Like	#8
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,001	You received already a lot very good advice IMHO. Having a K-3 myself, and having done the mistake once: could it be that the diopter adjustment dial (of your K-3 optical viewfinder) needs to be checked and adjusted? I might be completely wrong, but ...... might be worth a quick check,

02-15-2019, 11:01 PM	#9
Alnjpn Senior Member Join Date: May 2015 Location: Osaka Posts: 158 Original Poster	Thanks. I will post some pics later. I have dodgy eyes and have adjusted the viewfinder. reading around it seems as though it might just be that all the lenses need microadjustment. I will try that again too.

02-16-2019, 12:01 PM	#11
Crooski Loyal Site Supporter Join Date: Feb 2013 Location: Rozenburg , Zuid-Holland Photos: Gallery Posts: 3,678	Clean the autofocus sensor, under the mirror Not the mirror itself !

02-16-2019, 12:10 PM	#12
Madaboutpix Site Supporter Join Date: Dec 2011 Location: North Rhine-Westphalia Posts: 1,439	Originally posted by Alnjpn Is this (unreliable PD-AF) a K3 thing? Er, from my experience it isn't. Coming from a K-7, I'd say, if anything, my K-3 is focusing faster and more decisively, particularly in low light (including situations where the K-7 wouldn't have been able to obtain focus at all). As far as focus accuracy is concerned, under good conditions, both are pretty spot-on, though they struggle, at varying degrees, with sophisticated tracking (haven't been able to test the PLM 55-300 yet, which is K-3 compatible and might offer some improvement). And although I haven't done any serious tests, in four and a half years of use, with a fair range of lenses, I've never felt a need to fine-tune my K-3 for front- or back-focus issues. Therefore, my informal guess would be your issues are either due to sample variation or (perhaps more likely) dirt on the AF sensor.

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02-26-2019, 07:50 PM	#13
Alnjpn Senior Member Join Date: May 2015 Location: Osaka Posts: 158 Original Poster	Thanks for the feedback and sorry for the delay in getting back. I have been through and micro-adjusted all my lenses. This appears to have solved the issue for now. I haven't used them all in the field yet but with the ones I have, the focus is more reliable. Here are the adjustments: DA21 f3.2 +9 DA35 f2.4 +6 DA40 XS +5 DA50 f1.8 +4 DAL 55-300 +3 Sigma 17-50 None Sigma 10-20 None Interestingly the adjustments get less as the focal length gets shorter - not sure why would that be. Thanks again