Originally posted by Adam Manual lenses don't
truly have front/back focus issues, as AF confirmation is approximate and there's no AF motor to bring the lens's focus to the middle of the range.
As far as testing your lenses go, you should try using the technique described here:
Fixing Front and Back Focus - Introduction - PentaxForums.com
If all your AF lenses are off by that much, chances are it's your camera's fault.
Any lens can have true front/back focus issues. Different apertures can result in different planes ofoptimum sharpness...
Regarding the original question - proceedings to solve all problems. It appears that your camera AF is off. You can either apply a global fine adjustment correction for all lenses
or individual adjustments for all lenses that transmit a lens ID to the camera. Your manual glass will probably not transmit lens ID infortmation so you will probably end up using a global setting for all lenses. That said, your camera should not be off by 10 steps. It requires service, so you can basically start around 0 and not at the high/low end (debug software, discussing in this forum, will allow yout to make this adjustment yourself, but care should be taken). Even with a global correction setting, you can still evaluate the fine adjustment individually, but you need to set the values manually - prone to errors (what about a firmware option for setting AF adjustment for manual lenses in addition to focal length...).
Not ready yet! Fixing the AF trouble does not mean that you have fixed on screen manual focussing trouble. A misalignment of the screen for manual focussing independent of the AF sensor is possible. You need to check this as well and may have to order shims for fine adjustment. Typically more care is taken in positioning the screen as manual shimming can be a pain, but you never now. In case you are working with the focussing eyecup, amek sure to set your screen right.
Several reports in the last couple weeks have shown that K5 cameras were off by the maximum settable offset. This should not happen. Did I say that the red squares in the viewfinder can also be off - the red square is a projection based on where the AF sensor should be, but that does not ensure that it is where it is supposed to be. The real position can be off by +/-1 square in any direction...
AF fine tuning allows manual foucsing based on the focus control lamp in the viewfinder.
Real manual focussing requires screen based focussing.