[Belnan]

I converted a 16-50 to screw drive using debug mode on my K5. The focus seems spot on on my K5 but +10 still doesn't quite cut it on the K3. If I use a K5 to enter debug mode again to do a fine adjustment on the da* 16-50 will it stick with that copy on the lens regardless of the camera or only apply while using the K5?

[JohnX]

K5 only.

[Belnan]

Thanks. I haven't got the debug option on the K3 to work yet. I'll try again, perhaps I missed something.

[UncleVanya]

Thanks. I haven't got the debug option on the K3 to work yet. I'll try again, perhaps I missed something.

You don’t need to use debug on a k-3 the af fine adjustment is built into the firmware. Use the single lens option not the all lens option to have up to 20 data enabled lenses (f/fa/fa/DFA) adjustments remembered. Also bear in mind the adjustments typically are a combination of body and lens tolerances and aren’t likely identical across two bodies even with the same lens.

Edit: unless the maximum limit on setting fine adjustment isn’t enough.

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Last edited by UncleVanya; 08-17-2022 at 05:24 AM.

[eric1965]

Before doing AF fine adjustment, I would first check if PDAF sensor is clean (under mirror box) and the AF mirror is clean (a small mirror under the main mirror). Check if the backfocussing occurs with other lenses on your K3.
On a K3 II i had to put a general +60um in debug mode as a temp solution as all my lenses were backfocussing. With the general +60um I could adjust all my lenses correctly one by one in the camera custom settings. I finally reset everything and send the camera for repair verification and now everything works as it should.

[Belnan]

Before doing AF fine adjustment, I would first check if PDAF sensor is clean (under mirror box) and the AF mirror is clean (a small mirror under the main mirror). Check if the backfocussing occurs with other lenses on your K3.
On a K3 II i had to put a general +60um in debug mode as a temp solution as all my lenses were backfocussing. With the general +60um I could adjust all my lenses correctly one by one in the camera custom settings. I finally reset everything and send the camera for repair verification and now everything works as it should.

Good advice. Ill take a look at the sensor for good measure. As well have a look to see if there is a systematic issue.

---------- Post added 08-17-22 at 05:55 AM ----------

Follow up. I went into the debug mode of the K3 and made a 60um adjustment plus additional fine adjustment in camera. I will definitely try to look over the sensor when I get a bit more time and proper cleaning tools

[eric1965]

I did a similar screwdrive conversion on my 16-50mm SDM and I did not notice a severe focus shift from SDM to screwdrive - my SDM motor was dying it still worked at nearby distances and after some massaging I could go to infinity - After cleaning I would investigate further, preferably with known good working primes on your K5.
Please take note the focus shift in debug mode is not lens related it is camera related. If you do a shift of +60um on the camera your previously calibrated lens will need a 6 steps shift in negative. e.g. a +5 calibrated lens becomes a -1.
Hope this will help.
With Regards