Fixing Front and Back Focus on the K-x

Gustau · 02-01-2012, 10:44 AM

I have a back-focus problem with only one of my lenses (the FA35/2.0). Is there any way in which I can fix the focus problem for only this lens, or will the fix affect focus on all lenses?
I have also read elsewhere that the lack of single lens adjustment is a sneaky trick of Pentax to make you upgrade your camera, as the factory can actually do this individualized lens correction for you for a price. Not cool. Does anybody know how much do they charge for that?

theunartist · 02-01-2012, 11:21 AM

Originally posted by Gustau

I have a back-focus problem with only one of my lenses (the FA35/2.0). Is there any way in which I can fix the focus problem for only this lens, or will the fix affect focus on all lenses?
I have also read elsewhere that the lack of single lens adjustment is a sneaky trick of Pentax to make you upgrade your camera, as the factory can actually do this individualized lens correction for you for a price. Not cool. Does anybody know how much do they charge for that?

The Focus adjustment would apply to all lenses

Both my Pentax F 50/1.4 and 50/1.7 do not accurately focus on my K-x but do work well on my K20 which allows for individual AF fine tuning. The best and only real solution is to keep the debug mode on your SD card, and you can simply turn on/off and adjust when needed. PIA though but does work...

Good luck!

Check out this link: http://ricehigh.blogspot.com/2010/01/k-x-debug-mode-tutorial-af-adjustment.html

Marc Sabatella · 02-02-2012, 08:21 AM

Is the FA35 the only lens you have that is that fast? It's much more likely your *camera* has a BF issue that simly isn't visible with other lenses because the DOF isn't large enough. I have still yet to hear a credible technical explanation that woukd show how a lens, as opposed to a camera, could be backfousing, except for two very specific cases that would be easy to test for and wouldn't tend to actually be an issue in practice.

pishta · 06-28-2016, 12:28 PM

Debug doesnt work on my 1.03 K-x. I tried it 4 different ways. Even did a reset but no avail. The memory flashes twice and it goes right into "auto picture" mode or any other dial settings. I used this [OPEN_DEBUG_MENU] and I hit 'enter' after it so I was on line 2, then saved it as MODSET.492, but it showed up as MODSET.492 as a text file, does this sound correct? For full disclosure, I have a Tamron 28-200 lens mounted to it but it does same thing with no lens mounted.

02-01-2012, 10:44 AM	#16
Gustau New Member Join Date: Feb 2012 Posts: 2	selective focus correction in kX I have a back-focus problem with only one of my lenses (the FA35/2.0). Is there any way in which I can fix the focus problem for only this lens, or will the fix affect focus on all lenses? I have also read elsewhere that the lack of single lens adjustment is a sneaky trick of Pentax to make you upgrade your camera, as the factory can actually do this individualized lens correction for you for a price. Not cool. Does anybody know how much do they charge for that?

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02-01-2012, 11:21 AM	#17
theunartist Inactive Account Join Date: Oct 2010 Location: Baltimore Posts: 2,542 Original Poster	Originally posted by Gustau I have a back-focus problem with only one of my lenses (the FA35/2.0). Is there any way in which I can fix the focus problem for only this lens, or will the fix affect focus on all lenses? I have also read elsewhere that the lack of single lens adjustment is a sneaky trick of Pentax to make you upgrade your camera, as the factory can actually do this individualized lens correction for you for a price. Not cool. Does anybody know how much do they charge for that? The Focus adjustment would apply to all lenses Both my Pentax F 50/1.4 and 50/1.7 do not accurately focus on my K-x but do work well on my K20 which allows for individual AF fine tuning. The best and only real solution is to keep the debug mode on your SD card, and you can simply turn on/off and adjust when needed. PIA though but does work... Good luck! Check out this link: http://ricehigh.blogspot.com/2010/01/k-x-debug-mode-tutorial-af-adjustment.html

02-02-2012, 08:21 AM	#18
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Is the FA35 the only lens you have that is that fast? It's much more likely your camera has a BF issue that simly isn't visible with other lenses because the DOF isn't large enough. I have still yet to hear a credible technical explanation that woukd show how a lens, as opposed to a camera, could be backfousing, except for two very specific cases that would be easy to test for and wouldn't tend to actually be an issue in practice.

06-28-2016, 12:28 PM	#19
pishta Forum Member Join Date: May 2015 Posts: 92	Debug doesnt work on my 1.03 K-x. I tried it 4 different ways. Even did a reset but no avail. The memory flashes twice and it goes right into "auto picture" mode or any other dial settings. I used this [OPEN_DEBUG_MENU] and I hit 'enter' after it so I was on line 2, then saved it as MODSET.492, but it showed up as MODSET.492 as a text file, does this sound correct? For full disclosure, I have a Tamron 28-200 lens mounted to it but it does same thing with no lens mounted.