AF Fine Adjustment

Jim93 · 02-27-2018, 09:15 AM

I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target.

After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now.

I was just wondering...Is this a typical experience? Do other people have to do this?

Thanks, Jim

Adam · 02-27-2018, 09:43 AM - **1 Like**

Originally posted by Jim93

I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target.

After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now.

I was just wondering...Is this a typical experience? Do other people have to do this?

Thanks, Jim

While I'm not sure if I'd call it typical, having to apply AF adjustments is normal, especially if a single adjustment value improves the focusing accuracy of many different lenses. Many other users have gone through the same process as you

**BarryE** · 02-27-2018, 09:46 AM - **1 Like**

Originally posted by Jim93

I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target.

After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now.

I was just wondering...Is this a typical experience? Do other people have to do this?

Thanks, Jim

Hi Jim, yes very typical. I've done it with all my Pentax cameras and lenses. Interestingly, the lenses are similar in the adjustments needed, but the cameras differ. eg camera 1 needs lenses around +5. Camera 2 around +5. Camera three around +2. I've never seen one camera with my lenses varying by much more than around +or - 2. So it's the cameras that differ, in my experience. So your K-70 seems fine to me.

Just a note zooms vary across their range and a choice is often required to be made with the AF. I tend to choose AF setting for the fl I expect to mostly use the zoom.

pentaxfall · 02-27-2018, 11:12 AM - **1 Like**

Originally posted by Jim93

I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target.

After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now.

I was just wondering...Is this a typical experience? Do other people have to do this?

Thanks, Jim

I had to apply AF tuning for FA 50mm F1.4, Sigma 180mm macro & Tamron 28-75. I tested few months ago. I take AF tuning seriously and want the tests to be as scientific as possible; in the sense keep both target and camera in parallel planes; use MLU etc. I plan to retest again and then only apply the results to camera.

MikeStnly · 03-05-2018, 05:39 PM

I notice in the menu (K-3ii) that you can turn this off, apply all or apply one. If you use apply one, does it let you name the lens? Can you then do a second lens? I am assuming that different lenses may need different adjustments.

Mike

ejarray · 07-31-2018, 07:19 PM - **2 Likes**

Mike, several cameras are programmed to remember up to 20 distinct lenses when fine-tuning the focus...

labidas · 11-26-2018, 11:41 AM

I have a question about AF fine adjustment: what are the values?
What does +1 mean? Is it the same as +10um in DEBUG mode?

jcavadino · 12-22-2020, 01:49 AM

Originally posted by BarryE

Hi Jim, yes very typical. I've done it with all my Pentax cameras and lenses. Interestingly, the lenses are similar in the adjustments needed, but the cameras differ. eg camera 1 needs lenses around +5. Camera 2 around +5. Camera three around +2. I've never seen one camera with my lenses varying by much more than around +or - 2. So it's the cameras that differ, in my experience. So your K-70 seems fine to me.

Just a note zooms vary across their range and a choice is often required to be made with the AF. I tend to choose AF setting for the fl I expect to mostly use the zoom.

Hi, I am new to this forum and I noticed that you know how to calibrate lenses on the K70. I have one myself but in my menu the possibility to correct lenses is blocked out. In every setting. How do I get this menu item unchecked?
Best regards,

Arnout

tibbitts · 12-22-2020, 03:48 PM

Originally posted by jcavadino

Hi, I am new to this forum and I noticed that you know how to calibrate lenses on the K70. I have one myself but in my menu the possibility to correct lenses is blocked out. In every setting. How do I get this menu item unchecked?
Best regards,

Arnout

You will get better replies if you say the specific menu item you're looking at when you say "blocked out." List all the steps after pressing "Menu" you took to get to that point.

Belcik · 12-23-2020, 08:34 AM

Well - if you see that all of them are biased by the same amount, then maybe it makes sense to apply all?

02-27-2018, 09:15 AM	#1
Jim93 New Member Join Date: Feb 2018 Posts: 2	AF Fine Adjustment I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target. After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now. I was just wondering...Is this a typical experience? Do other people have to do this? Thanks, Jim

02-27-2018, 09:43 AM - 1 Like	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by Jim93 I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target. After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now. I was just wondering...Is this a typical experience? Do other people have to do this? Thanks, Jim While I'm not sure if I'd call it typical, having to apply AF adjustments is normal, especially if a single adjustment value improves the focusing accuracy of many different lenses. Many other users have gone through the same process as you 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:

07-31-2018, 07:19 PM - 2 Likes	#6
ejarray New Member Join Date: Jun 2012 Photos: Gallery \| Albums Posts: 4	Fine Tuning auto-focus Lenses Mike, several cameras are programmed to remember up to 20 distinct lenses when fine-tuning the focus...

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02-27-2018, 09:46 AM - 1 Like	#3
BarryE Site Supporter Join Date: Jan 2013 Location: Hampshire, UK Posts: 1,653	Originally posted by Jim93 I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target. After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now. I was just wondering...Is this a typical experience? Do other people have to do this? Thanks, Jim Hi Jim, yes very typical. I've done it with all my Pentax cameras and lenses. Interestingly, the lenses are similar in the adjustments needed, but the cameras differ. eg camera 1 needs lenses around +5. Camera 2 around +5. Camera three around +2. I've never seen one camera with my lenses varying by much more than around +or - 2. So it's the cameras that differ, in my experience. So your K-70 seems fine to me. Just a note zooms vary across their range and a choice is often required to be made with the AF. I tend to choose AF setting for the fl I expect to mostly use the zoom.

02-27-2018, 11:12 AM - 1 Like	#4
pentaxfall Veteran Member Join Date: Sep 2017 Location: Bangalore, India Posts: 581	Originally posted by Jim93 I've been experimenting with my new K-70. I wasn't happy that the viewfinder auto-focus was working correctly, so I checked it out with one of those card lens focus calibration tools. I discovered that all three of my lenses were focussing significantly in-front of the target. After a few hours trying different settings I have settled on applying a -8 adjustment for all lenses. All seems fine now. I was just wondering...Is this a typical experience? Do other people have to do this? Thanks, Jim I had to apply AF tuning for FA 50mm F1.4, Sigma 180mm macro & Tamron 28-75. I tested few months ago. I take AF tuning seriously and want the tests to be as scientific as possible; in the sense keep both target and camera in parallel planes; use MLU etc. I plan to retest again and then only apply the results to camera.

03-05-2018, 05:39 PM	#5
MikeStnly Senior Member Join Date: Jun 2012 Location: Algonquin Highlands Posts: 249	I notice in the menu (K-3ii) that you can turn this off, apply all or apply one. If you use apply one, does it let you name the lens? Can you then do a second lens? I am assuming that different lenses may need different adjustments. Mike

11-26-2018, 11:41 AM	#7
labidas Forum Member Join Date: Apr 2018 Location: Tartu Posts: 82	I have a question about AF fine adjustment: what are the values? What does +1 mean? Is it the same as +10um in DEBUG mode?

12-22-2020, 01:49 AM	#8
jcavadino New Member Join Date: Dec 2020 Posts: 1	Originally posted by BarryE Hi Jim, yes very typical. I've done it with all my Pentax cameras and lenses. Interestingly, the lenses are similar in the adjustments needed, but the cameras differ. eg camera 1 needs lenses around +5. Camera 2 around +5. Camera three around +2. I've never seen one camera with my lenses varying by much more than around +or - 2. So it's the cameras that differ, in my experience. So your K-70 seems fine to me. Just a note zooms vary across their range and a choice is often required to be made with the AF. I tend to choose AF setting for the fl I expect to mostly use the zoom. Hi, I am new to this forum and I noticed that you know how to calibrate lenses on the K70. I have one myself but in my menu the possibility to correct lenses is blocked out. In every setting. How do I get this menu item unchecked? Best regards, Arnout

12-22-2020, 03:48 PM	#9
tibbitts Pentaxian Join Date: Apr 2007 Location: Oklahoma USA Posts: 2,193	Originally posted by jcavadino Hi, I am new to this forum and I noticed that you know how to calibrate lenses on the K70. I have one myself but in my menu the possibility to correct lenses is blocked out. In every setting. How do I get this menu item unchecked? Best regards, Arnout You will get better replies if you say the specific menu item you're looking at when you say "blocked out." List all the steps after pressing "Menu" you took to get to that point.

12-23-2020, 08:34 AM	#10
Belcik Veteran Member Join Date: Feb 2009 Location: Russia,Moscow Photos: Gallery \| Albums Posts: 377	Well - if you see that all of them are biased by the same amount, then maybe it makes sense to apply all?