Sylwester Pietrzyk wrote:
Toralf Lund wrote on 04.10.05 10:06:
I must admit that although I've tried some of the never Canons and
Nikons, I've only shot a couple of pictures with each. I wasn't
immediately struck by any important differences in the AF, though.
Quieter, perhaps, but "more efficient"?
USM is not faster, at least until you have very long lens with heavy optics.
It is in-camera AF system that is responsible for accurate and sure
focusing. Differencies in AF performance are visible in low light. Here from
what I've tried so far Nikon performs best with their CAM-2000 system used
in D2 series DSLRs and in F6. It has identical number, type and placement of
AF sensors as in Safox VIII used in istD, but the difference in performance
under low light is huge in favour of Nikon.
Ring-type in-lens motors (USM/AF-S Ring-type) are faster, in all but the
lightest lenses. You can easily verify this with a Nikon body like the
D70 or F80, by switching between say a 28-105 (Body-driven) and a 24-120
AF-S. The speed differences are quite notable on anything except a light
prime (Where even Canon doesn't always use USM, or occasionally uses
micro-motor USM, which is not faster than a good in-body motor). Combine
this with a more sensitive AF unit and better AF code and you have an
even bigger gap.
My experience is that the AF unit and motor in the D70 is generally
inferior to the SAFOX VIII, except in very low light and focus tracking.
The 4 outer poiints in the Multi-CAM900 are thoroughly useless, while
all but the two outermost in the SAFOX VIII are usable in most situations.
-Adam
