AF speed D700 slower than D3? how come ?

Started Aug 7, 2009 | Discussions thread
Marianne Oelund Veteran Member • Posts: 7,360
Re: actual data please?
1

TheronFamily wrote:

Hi Marianne. I am in need of the actual values you derived from your tests please. Would that be feasible? (the ms values). Apologies if it was published and I overlooked it.

I haven't located all of my notes, but do have some timings for the 200-400 with the D3 and D7000.  For the slew-speed test, which involves a full infinity-closest-infinity search cycle, i.e., just a measurement of the max motor speed, I have

D3 @400mm, 2.24sec; @200mm, 1.15sec

D7000 @400mm, 2.99sec; @200mm, 1.06sec

Of course, there is more to focus speed than the motor's drive rate, and I recommend that you see the data presented on this other thread.

Further, this is for a single focus cycle only, correct? What would happen in the case of continuous focus in a burst? Would the "last remembered" focus point be the starting point for the next focus cycle? I presume it would.

Yes to both.  Focus tracking during a burst generally keeps up with the frame rate, and this is an area where I like the Nikon implementation over Canon's since it doesn't allow AF to slow down the frame rate when shutter-release priority is used.

Again, may I please obtain the ms values for this test?

I haven't found my notes for the AF-initial-delay tests.

A question re. this "cycle" is how the mirror to rest time affects the outcomes, or was that not computed or needed?

I think you will find the data from the thread referenced above, to provide the best answer.  It considers all of the delays involved from AF initiation, to the moment of exposure.

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