Caution ! Dynamic AF versus single point AF... !

SteveL54 wrote:

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You are talking about the RGB sensor that is in the viewfinder -- not the phase detection AF module which does the actual focusing measurements. The manual explains it helps with auto-area AF's face detection and 3D tracking, but doesn't say how it works with single area and dynamic area focusing. I suppose it can augment the tracking done in dynamic area by following the color of the selected target. The RGB sensor helps determine what focus point is used for AF if the AF mode allows a choice, so there may be differences in this selection process with the new RGB sensor. However, the major difference between single point AF and multi point AF modes remains the same. Multi point AF has allowed the outer points to be selected on initial acquisition if the selected point does not have enough contrast.

Anyway I'm not aware the phase detection AF module has been given any more pixels since the D3. I could be wrong about the newer phase detect module naming convention, but back in the CAM 2000 period and before, Nikon states that the module's name is derived from the number of AF pixels. See this Nikon article:

http://imaging.nikon.com/history/scenes/08/index.htm

So the Multi-CAM 3500 would have 3500 total pixels in the AF unit. They've tweaked the minimum aperture requirement for the central points and reduced the light level specification for the D4 and D800, but no mention of any finer resolution.

Steve