OK, I just looked it up. If I understand it correctly, the default focusing mode for live view is based on contrast as detected by the imaging sensor. Focusing through the optical system uses a separate phase detection sensor.
I guess the method assumes that the live view, contrast-based autofocus system is correct. So an adjustment must be made to the phase-based system to correct any focusing errors in the phase-based system. Evidently, the micro-focus adjustments must not effect the live view, contrast-based focusing system. Otherwise, once you made a microfocus correction, it would seem to me that it would throw off the, previously correct, live-view focusing system. So does that lead to the conclusion that all of this back-focusing business is really a problem with the autofocus system? Otherwise, if the lens was not focusing properly, it should be equally bad through both focusing systems. If that's true people should be saying this "camera body back-focuses with this lens" instead of the more commonly phrased "this lens has a back-focus problem." On the other hand, a guy with two watches never knows the correct time. gs George Sinos -------------------- [email protected] www.georgesphotos.net plus.georgesinos.com On Wed, Apr 4, 2012 at 1:06 PM, Matthew Hunt <[email protected]> wrote: > On Wed, Apr 4, 2012 at 2:01 PM, George Sinos <[email protected]> wrote: > >> I'm not sure what is being accomplished here. How do you know which >> of the two focusing methods techniques is errant? > > Live View is correct, by definition. It's based directly on the imaging > sensor. > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
