Tu jest dyskusja na ten temat:
(http://forums.dpreview.com/forums/re...ssage=23424428)

Poniżej podsumowanie dot. MkIII
(wyciąłem i wyedytowałem z ww. wątku:
http://forums.dpreview.com/forums/re...ssage=23439256)

Exphose wrote:
> Based on Maximum Aperature at Focal length selected of lens/tc combo.
> ===========================
> F2.8 and faster lenses (F1.4 for example) :
> 19 AF points are High Precision & Cross Type
> 26 Assist AF points are Horizontal Only
> ===========================
> F2.9 to F4 lenses are:
> 1 center AF point is High Precision & Cross Type
> 18 AF points are Horizontal Only
> 26 Assist AF points are Horizontal Only
> ===========================
> F4.1 to F5.6 lenses are:
> All AF points are Horizontal Only
> ===========================
> F5.7 to F8 lenses are:
> 1 center only horizontal AF
> ===========================
> F8.1 to F64 lenses are:
> No AF Supported


Tutaj wycięte z innego wątku dot. 20D/30D/5D:
(http://forums.dpreview.com/forums/re...ssage=23411429)

bullet1:
The center cross sensor on the 20D/30D/5D can operate up to f5.6 while the center cross sensor on 1 series including 1D3 only operate up to f4.

What does that mean? Putting the 100-400 f/4.5-5.6L IS lens on any 1 series body will deactivate all cross type sensors including the precious center one.

Yes the center sensor on 1 series will operate up to F8 but is one direction only (vertical). One has to AF in 45 degrees to detect both horizontal and vertical lines. At least this is the way I gather from the manuals and white papers.

The center sensor on the lower cameras such as the 5D, will still operate as a cross sensor with the 100-400 f/4.5-5.6. I was a bit surprised by this as I am planning to get the 1D3 or 1D2n.


Tu są fragmenty instrukcji:
http://www.pbase.com/nelsonc/af_points