Grey market lenses and AF calibration

jchrysostom · 09-24-2019, 06:23 AM

Greetings. I recently upgraded from a K5ii-s to a K1 and I'm having trouble with lens calibration. My two main lenses are both Tamrons, a 28-75 f/2.8 and a 70-200 f/2.8. The 28-75 was a "grey market" eBay purchase made about 5 years ago; it worked wonderfully with a -4 AF Fine Adjustment on my K5, but on the K1 it has a huge front-focus that can't be solved with the K1's AF adjustment range. At -10, with the camera about 3' from the subject, the focus plane is still at least 1" in front of the subject, enough error that when using the lens it is clear on the camera's screen that the lens is front-focusing.

Tamron's website says they won't even work on grey market lenses and I'm not sure that I would still have a warranty even if the lens were an authorized import. I'm not sure what service Pentax offers with 3rd party lenses. Is there an option for dealing with this at some reasonable cost, or should I be putting the lens on eBay and moving on?

vector · 09-24-2019, 06:48 AM

I have a Tamron 28-75 with a similar problem though not so severe. On my K5 and K3 it was good with a -10 adjustment but on my K1 it wasn't enough. Initially I didn't change anything as it was close enough that if I avoided F2.8 it was ok and found myself shooting primes more with my K1. Later I discovered debug mode and was able to do a global adjustment of -1 which made -10 correct for my 28-75. I believe accessing debug mode may risk voiding your warranty though so you may not want to do that.

For the price of a used replacement I would say try another one from ebay and sell yours on. Every camera lens combination is just a little different so your lens is most likely perfectly fine on another K1.

pschlute · 09-24-2019, 07:49 AM

Originally posted by jchrysostom

it worked wonderfully with a -4 AF Fine Adjustment on my K5, but on the K1 it has a huge front-focus that can't be solved with the K1's AF adjustment range. At -10, with the camera about 3' from the subject, the focus plane is still at least 1" in front of the subject,

1.What is the lens like at different focal lengths and at subjects further away than 3 foot ? it is very common for both extremes of a zoom to focus slightly differently.

2. What is the 70-200 lens like ? what BF/FF adjustment did it need on the K5ii and what does it need on the K1 ? This might shed some light on whether your K1 AF sensor is the major culprit. If it is You can send the K1 to Pentax and they will reset the AF sensor for free.

zapp · 09-24-2019, 08:47 AM

To get better results you should send lens AND camera in. K1 may be off as well in your case. Lens and camera just need overlap within their adjustment range. If the camera is on warranty, adjusting the camera should be free.

**BigMackCam** · 09-24-2019, 08:55 AM

This is a fairly common problem with older film-era Tamron lenses. I'm guessing their test rig wasn't too accurate, or quality control simply wasn't tight (modern Tamron lenses are usually well adjusted from the factory). I have a grey market Tamron 28-75 f/2.8 that, when purchased, would not reach perfect focus within the AF fine adjustment range of my K-3, and went through two copies of the 70-200 f/2.8 before giving up and buying the DA*60-250 f/4.

Here in the UK, Tamron's service centre will service and/or adjust grey market lenses, but they charge for it (i.e. they won't do it under warranty), which is fair enough. They adjusted my 28-75 without needing my camera... it now requires -4 fine adjustment on my K-3 and K-3II, when most Pentax lenses require 0 or +/-2 at worst. I'm happy with that. However, as @zapp states above, for guaranteed results you might be better off sending the camera body with the lens.

jchrysostom · 09-24-2019, 09:01 AM

Originally posted by pschlute

1.What is the lens like at different focal lengths and at subjects further away than 3 foot ? it is very common for both extremes of a zoom to focus slightly differently.

2. What is the 70-200 lens like ? what BF/FF adjustment did it need on the K5ii and what does it need on the K1 ? This might shed some light on whether your K1 AF sensor is the major culprit. If it is You can send the K1 to Pentax and they will reset the AF sensor for free.

The 28-75 is front-focusing at all distances and focal lengths. I noticed it this weekend; I took my kid for a mountain hike and snapped a few photos of him sitting on a rock at the summit, and it was obvious at a glance that the focal plane was roughly at his knees even though the camera indicated focus on his face, a 2ft difference at 15 feet. This was before I did the -10 AF adjustment but it's still off.

I don't remember what setting I am at for the 70-200 but it's not very much. I also don't remember what settings I landed on with the K5 but I can check that later today.

---------- Post added 09-24-19 at 09:02 AM ----------

Originally posted by zapp

To get better results you should send lens AND camera in. K1 may be off as well in your case. Lens and camera just need overlap within their adjustment range. If the camera is on warranty, adjusting the camera should be free.

Will Pentax/Ricoh work on a body/lens combo if the lens is 3rd party?

pschlute · 09-24-2019, 09:39 AM - **1 Like**

Originally posted by jchrysostom

Will Pentax/Ricoh work on a body/lens combo if the lens is 3rd party?

They probably would. But this might not be a good idea. You will basically be telling then to match your K1 with an out of alignment lens. While that combo will work fine afterwards, every other lens you plonk on the camera will back-focus like crazy. They wont do anything to the lens itself.

jchrysostom · 09-24-2019, 10:08 AM

New idea... I understand that there is a "debug mode" which allows you to access a greater range of AF adjustment. I haven't had much luck finding solid info about accessing this mode on a K1. Help?

pschlute · 09-24-2019, 10:47 AM

Originally posted by jchrysostom

New idea... I understand that there is a "debug mode" which allows you to access a greater range of AF adjustment. I haven't had much luck finding solid info about accessing this mode on a K1. Help?

No idea and I would not attempt it.

please remember that global changes to the AF/FA setting and individual changes are not cumulative. So probably wont help.

jchrysostom · 09-24-2019, 01:07 PM

Originally posted by pschlute

No idea and I would not attempt it.

please remember that global changes to the AF/FA setting and individual changes are not cumulative. So probably wont help.

I read the opposite in several places, at least as it concerns the debug mode adjustment.

pschlute · 09-24-2019, 02:44 PM

Originally posted by jchrysostom

I read the opposite in several places, at least as it concerns the debug mode adjustment.

Well , there is only one way to find out. Certainly all the menu based AF/FA settings do not allow cumulative adjustment.

jchrysostom · 09-24-2019, 07:25 PM

Originally posted by pschlute

Well , there is only one way to find out. Certainly all the menu based AF/FA settings do not allow cumulative adjustment.

I read in a few different places that the debug mode adjustments stack, that being how Pentax would adjust the camera if you sent it in. I may try it if I can’t get acceptable results with the regular adjustment and range.

vector · 09-25-2019, 09:53 AM

If you want to risk firmware hacking the instructions for setting up the files on your SD card are here:
Resurrecting Pentax firmware hacking - Page 42 - PentaxForums.com

- Create the files on the card as describe in the above post
- Put the card in slot 1, leave the card door open
- Hold in Menu when you power on
- When the menu comes up the first item in the list is Enable Debug. Set it to Yes and hit OK.

- Then turn off the camera and close the card door
- Turn camera back on and the debug menu will show up. Just hit ok and your camera will now be usable.
- Press menu and scroll over to the right. Just after the wrench menu tabs there is a hidden tab called TEST MODE.

- In TEST MODE menu choose AF TEST
- For focus tuning here 10um=1 from the normal AF Fine Adjustment menu. Anything you set here will be additive to your other AF Fine Adjustments.

- When you are done turn off and back on your camera so the Debug Menu pops up and disable Debug Mode.

jchrysostom · 09-25-2019, 10:11 AM

Originally posted by vector

If you want to risk firmware hacking the instructions for setting up the files on your SD card are here:
Resurrecting Pentax firmware hacking - Page 42 - PentaxForums.com

- Create the files on the card as describe in the above post
- Put the card in slot 1, leave the card door open
- Hold in Menu when you power on
- When the menu comes up the first item in the list is Enable Debug. Set it to Yes and hit OK.

- Then turn off the camera and close the card door
- Turn camera back on and the debug menu will show up. Just hit ok and your camera will now be usable.
- Press menu and scroll over to the right. Just after the wrench menu tabs there is a hidden tab called TEST MODE.

- In TEST MODE menu choose AF TEST
- For focus tuning here 10um=1 from the normal AF Fine Adjustment menu. Anything you set here will be additive to your other AF Fine Adjustments.

- When you are done turn off and back on your camera so the Debug Menu pops up and disable Debug Mode.

Thanks for the direct link. I read that thread/post, but I'm a bit confused about "hexeditor". I also found a thread on a different site which included links to a Dropbox with the files already created, but again the reference to "hex" and I'm not sure what it means.

vector · 09-25-2019, 10:51 AM - **1 Like**

PM sent about the files. A hex editor is a tool used to write/edit binary data and represent it in a more human friendly format. One of those files is just text with the command to open the menu, the other has binary data, not actually sure what it is.

---------- Post added 09-25-19 at 11:57 AM ----------

I should note that the adjustment is global and additive so first off make note of the setting it is at now. Then add/remove in 10um steps. Any lens you have already done fine adjustment for will need to be readjusted with the same number of steps. I have done this on my K1 and K5 and found the both came from the factory with an offset already in place (they were not at +/-0) which further reinforces the likelihood that this is how the cameras are initially calibrated at the factory, and if you send it in they are probably using this first before trying to mechanically adjust a camera.

09-24-2019, 06:23 AM	#1
jchrysostom New Member Join Date: Aug 2018 Posts: 16	Grey market lenses and AF calibration Greetings. I recently upgraded from a K5ii-s to a K1 and I'm having trouble with lens calibration. My two main lenses are both Tamrons, a 28-75 f/2.8 and a 70-200 f/2.8. The 28-75 was a "grey market" eBay purchase made about 5 years ago; it worked wonderfully with a -4 AF Fine Adjustment on my K5, but on the K1 it has a huge front-focus that can't be solved with the K1's AF adjustment range. At -10, with the camera about 3' from the subject, the focus plane is still at least 1" in front of the subject, enough error that when using the lens it is clear on the camera's screen that the lens is front-focusing. Tamron's website says they won't even work on grey market lenses and I'm not sure that I would still have a warranty even if the lens were an authorized import. I'm not sure what service Pentax offers with 3rd party lenses. Is there an option for dealing with this at some reasonable cost, or should I be putting the lens on eBay and moving on?

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09-24-2019, 06:48 AM	#2
vector Pentaxian Join Date: May 2015 Location: Alberta Posts: 713	I have a Tamron 28-75 with a similar problem though not so severe. On my K5 and K3 it was good with a -10 adjustment but on my K1 it wasn't enough. Initially I didn't change anything as it was close enough that if I avoided F2.8 it was ok and found myself shooting primes more with my K1. Later I discovered debug mode and was able to do a global adjustment of -1 which made -10 correct for my 28-75. I believe accessing debug mode may risk voiding your warranty though so you may not want to do that. For the price of a used replacement I would say try another one from ebay and sell yours on. Every camera lens combination is just a little different so your lens is most likely perfectly fine on another K1.

09-24-2019, 07:49 AM	#3
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,211	Originally posted by jchrysostom it worked wonderfully with a -4 AF Fine Adjustment on my K5, but on the K1 it has a huge front-focus that can't be solved with the K1's AF adjustment range. At -10, with the camera about 3' from the subject, the focus plane is still at least 1" in front of the subject, 1.What is the lens like at different focal lengths and at subjects further away than 3 foot ? it is very common for both extremes of a zoom to focus slightly differently. 2. What is the 70-200 lens like ? what BF/FF adjustment did it need on the K5ii and what does it need on the K1 ? This might shed some light on whether your K1 AF sensor is the major culprit. If it is You can send the K1 to Pentax and they will reset the AF sensor for free.

09-24-2019, 08:47 AM	#4
zapp Pentaxian Join Date: Jul 2011 Posts: 2,388	To get better results you should send lens AND camera in. K1 may be off as well in your case. Lens and camera just need overlap within their adjustment range. If the camera is on warranty, adjusting the camera should be free.

09-24-2019, 08:55 AM	#5
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,686	This is a fairly common problem with older film-era Tamron lenses. I'm guessing their test rig wasn't too accurate, or quality control simply wasn't tight (modern Tamron lenses are usually well adjusted from the factory). I have a grey market Tamron 28-75 f/2.8 that, when purchased, would not reach perfect focus within the AF fine adjustment range of my K-3, and went through two copies of the 70-200 f/2.8 before giving up and buying the DA*60-250 f/4. Here in the UK, Tamron's service centre will service and/or adjust grey market lenses, but they charge for it (i.e. they won't do it under warranty), which is fair enough. They adjusted my 28-75 without needing my camera... it now requires -4 fine adjustment on my K-3 and K-3II, when most Pentax lenses require 0 or +/-2 at worst. I'm happy with that. However, as @zapp states above, for guaranteed results you might be better off sending the camera body with the lens.

09-24-2019, 09:01 AM	#6
jchrysostom New Member Join Date: Aug 2018 Posts: 16 Original Poster	Originally posted by pschlute 1.What is the lens like at different focal lengths and at subjects further away than 3 foot ? it is very common for both extremes of a zoom to focus slightly differently. 2. What is the 70-200 lens like ? what BF/FF adjustment did it need on the K5ii and what does it need on the K1 ? This might shed some light on whether your K1 AF sensor is the major culprit. If it is You can send the K1 to Pentax and they will reset the AF sensor for free. The 28-75 is front-focusing at all distances and focal lengths. I noticed it this weekend; I took my kid for a mountain hike and snapped a few photos of him sitting on a rock at the summit, and it was obvious at a glance that the focal plane was roughly at his knees even though the camera indicated focus on his face, a 2ft difference at 15 feet. This was before I did the -10 AF adjustment but it's still off. I don't remember what setting I am at for the 70-200 but it's not very much. I also don't remember what settings I landed on with the K5 but I can check that later today. ---------- Post added 09-24-19 at 09:02 AM ---------- Originally posted by zapp To get better results you should send lens AND camera in. K1 may be off as well in your case. Lens and camera just need overlap within their adjustment range. If the camera is on warranty, adjusting the camera should be free. Will Pentax/Ricoh work on a body/lens combo if the lens is 3rd party?

09-24-2019, 09:39 AM - 1 Like	#7
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,211	Originally posted by jchrysostom Will Pentax/Ricoh work on a body/lens combo if the lens is 3rd party? They probably would. But this might not be a good idea. You will basically be telling then to match your K1 with an out of alignment lens. While that combo will work fine afterwards, every other lens you plonk on the camera will back-focus like crazy. They wont do anything to the lens itself.

09-24-2019, 10:08 AM	#8
jchrysostom New Member Join Date: Aug 2018 Posts: 16 Original Poster	New idea... I understand that there is a "debug mode" which allows you to access a greater range of AF adjustment. I haven't had much luck finding solid info about accessing this mode on a K1. Help?

09-24-2019, 10:47 AM	#9
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,211	Originally posted by jchrysostom New idea... I understand that there is a "debug mode" which allows you to access a greater range of AF adjustment. I haven't had much luck finding solid info about accessing this mode on a K1. Help? No idea and I would not attempt it. please remember that global changes to the AF/FA setting and individual changes are not cumulative. So probably wont help.

09-24-2019, 01:07 PM	#10
jchrysostom New Member Join Date: Aug 2018 Posts: 16 Original Poster	Originally posted by pschlute No idea and I would not attempt it. please remember that global changes to the AF/FA setting and individual changes are not cumulative. So probably wont help. I read the opposite in several places, at least as it concerns the debug mode adjustment.

09-24-2019, 02:44 PM	#11
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,211	Originally posted by jchrysostom I read the opposite in several places, at least as it concerns the debug mode adjustment. Well , there is only one way to find out. Certainly all the menu based AF/FA settings do not allow cumulative adjustment.

09-24-2019, 07:25 PM	#12
jchrysostom New Member Join Date: Aug 2018 Posts: 16 Original Poster	Originally posted by pschlute Well , there is only one way to find out. Certainly all the menu based AF/FA settings do not allow cumulative adjustment. I read in a few different places that the debug mode adjustments stack, that being how Pentax would adjust the camera if you sent it in. I may try it if I can’t get acceptable results with the regular adjustment and range.

09-25-2019, 09:53 AM	#13
vector Pentaxian Join Date: May 2015 Location: Alberta Posts: 713	If you want to risk firmware hacking the instructions for setting up the files on your SD card are here: Resurrecting Pentax firmware hacking - Page 42 - PentaxForums.com - Create the files on the card as describe in the above post - Put the card in slot 1, leave the card door open - Hold in Menu when you power on - When the menu comes up the first item in the list is Enable Debug. Set it to Yes and hit OK. - Then turn off the camera and close the card door - Turn camera back on and the debug menu will show up. Just hit ok and your camera will now be usable. - Press menu and scroll over to the right. Just after the wrench menu tabs there is a hidden tab called TEST MODE. - In TEST MODE menu choose AF TEST - For focus tuning here 10um=1 from the normal AF Fine Adjustment menu. Anything you set here will be additive to your other AF Fine Adjustments. - When you are done turn off and back on your camera so the Debug Menu pops up and disable Debug Mode.

09-25-2019, 10:11 AM	#14
jchrysostom New Member Join Date: Aug 2018 Posts: 16 Original Poster	Originally posted by vector If you want to risk firmware hacking the instructions for setting up the files on your SD card are here: Resurrecting Pentax firmware hacking - Page 42 - PentaxForums.com - Create the files on the card as describe in the above post - Put the card in slot 1, leave the card door open - Hold in Menu when you power on - When the menu comes up the first item in the list is Enable Debug. Set it to Yes and hit OK. - Then turn off the camera and close the card door - Turn camera back on and the debug menu will show up. Just hit ok and your camera will now be usable. - Press menu and scroll over to the right. Just after the wrench menu tabs there is a hidden tab called TEST MODE. - In TEST MODE menu choose AF TEST - For focus tuning here 10um=1 from the normal AF Fine Adjustment menu. Anything you set here will be additive to your other AF Fine Adjustments. - When you are done turn off and back on your camera so the Debug Menu pops up and disable Debug Mode. Thanks for the direct link. I read that thread/post, but I'm a bit confused about "hexeditor". I also found a thread on a different site which included links to a Dropbox with the files already created, but again the reference to "hex" and I'm not sure what it means.

09-25-2019, 10:51 AM - 1 Like	#15
vector Pentaxian Join Date: May 2015 Location: Alberta Posts: 713	PM sent about the files. A hex editor is a tool used to write/edit binary data and represent it in a more human friendly format. One of those files is just text with the command to open the menu, the other has binary data, not actually sure what it is. ---------- Post added 09-25-19 at 11:57 AM ---------- I should note that the adjustment is global and additive so first off make note of the setting it is at now. Then add/remove in 10um steps. Any lens you have already done fine adjustment for will need to be readjusted with the same number of steps. I have done this on my K1 and K5 and found the both came from the factory with an offset already in place (they were not at +/-0) which further reinforces the likelihood that this is how the cameras are initially calibrated at the factory, and if you send it in they are probably using this first before trying to mechanically adjust a camera.