07-26-2012, 03:49 PM
Front focus = lens/camera focuses in front of intended focus point
Back focus = behind
Many cameras, including D3s, have a function to adjust the autofocus system precisely for particular lenses, as individual lenses may require this adjustment.
Occasionally, the camera autofocus system may require (re-)calibration - as my D7000 did after I dropped it, although I initially thought a particular lens might be faulty (see [url="http://forum.photozone.de/index.php?/topic/1426-nikon-12-24mm-af-back-focus/page__p__12425__fromsearch__1#entry12425"]this thread[/url]). As you'll see from this thread, establishing whether a lens, several lenses, or the camera is auto-focusing inaccurately can be a bit time-consuming and quite hassly (at least it was for me!)
Roger Cicala has written several interesting articles about the influence of lens-camera body combinations (two examples [url="http://www.lensrentals.com/blog/2008/12/this-lens-is-soft-and-other-myths"]here[/url] and [url="http://www.lensrentals.com/blog/2011/10/notes-on-lens-and-camera-variation"]here[/url]). Some people advocate calibrating all lenses - possibly with the body / bodies they're to be used with.
Ian
Back focus = behind
Many cameras, including D3s, have a function to adjust the autofocus system precisely for particular lenses, as individual lenses may require this adjustment.
Occasionally, the camera autofocus system may require (re-)calibration - as my D7000 did after I dropped it, although I initially thought a particular lens might be faulty (see [url="http://forum.photozone.de/index.php?/topic/1426-nikon-12-24mm-af-back-focus/page__p__12425__fromsearch__1#entry12425"]this thread[/url]). As you'll see from this thread, establishing whether a lens, several lenses, or the camera is auto-focusing inaccurately can be a bit time-consuming and quite hassly (at least it was for me!)
Roger Cicala has written several interesting articles about the influence of lens-camera body combinations (two examples [url="http://www.lensrentals.com/blog/2008/12/this-lens-is-soft-and-other-myths"]here[/url] and [url="http://www.lensrentals.com/blog/2011/10/notes-on-lens-and-camera-variation"]here[/url]). Some people advocate calibrating all lenses - possibly with the body / bodies they're to be used with.
Ian