casperwb said:
therefore, is it safe to say that these cameras are smater that most users?

Is a pencil sharpener smarter than a user with a knife?

I mean, seriously, even the most advanced camera is nothing more than a tool meant to automate a task in a deterministic manner. It isn't "smarter" than anything.

therefore, is it safe to say that these cameras are smater that most users?

I think it's impossible for someone outside of Nikon to have access to information beyond a certain level. In my post I said "99% of what I'm saying you can get from the Nikon imaging site. You might have to read D3S info and read between the lines a little bit. But enough information is there to draw conclusions".

Here's a direct extract from one of the articles. I'm not sure what else I can conclude from it.

"Based on distance-to-skin information obtained by G- and D-type AF NIKKOR lenses, the camera is able to calculate proportions of and determine the presence and position of a person."

and another

"D-type and G-type NIKKOR lenses relay subject-to-camera distance information to AF Nikon camera bodies. This then makes possible advances like 3D Matrix Metering and 3D Multi-Sensor Balanced Fill-Flash."

rbid said:
but as far I know, the camera tells the lens to move the focus distance, therefore why the camera needs to read back that info?

Partially.
The camera AF drive is lens-agnostic, and does not need a known-distance to work. It can see the effect each degree* of screw-drive turn creates and can calc based on that.

*or whatever unit they are using internally.

Forgive my ignorance.. but as far I know, the camera tells the lens to move the focus distance, therefore why the camera needs to read back that info? (I guess that the only situation is when you use the focusing ring). The focus points are computed and discovered by the camera and not by the lens.. is this correct?

I think I misread your question the first time.

The D7000 has several different technologies built into it. Predictive Focus Tracking, the 2016 pixel RGB Sensor, and the Scene Recognition System. These systems can work in whole or in part and can work independently or in conjunction with another technology component. For example, a series G or D lens can pass in distance information to SRS but distance information isn't required for SRS to be used. When SRS has distance information then it's capable of face recognition.
Consider the differences between the Dynamic 39 Point AF and 3D Tracking AF. Dynamic 39 Point is using phase detection and the Predictive Focus Tracking. Predictive Focus Tracking is tracking the subject movement toward and away from the camera. The 3D Tracking mode is using color information from the RGB Sensor and SRS for subject identification. If distance information is available then it can also recognize faces and pass that info to aid tracking the subject. The 3D term comes from the inclusion of distance information.

99% of what I'm saying you can get from the Nikon imaging site. You might have to read D3S info and read between the lines a little bit. But enough information is there to draw conclusions. But thinking that 3D is available with a pre G/D is incorrect. I hope I've helped even though I've left the real research to you.

You can shoot in any mode. The camera is smart enough to use what it can and change enough to make the exposure. The camera doesn't tell you it changed it or prevent you from being in any mode.

I shoot a 50mm and 24mm ais lens all the time and leave it to 3D matrix. It actually reacts more like a center weighted meter although it doesn't recored it or tell you it is.

On page 310 of the manual it says
Matrix: 3D color matrix metering II (type G and D lenses); color matrix metering II (other CPU lenses); color matrix metering available with non-CPU lenses if user provides lens data.

A type G or D lens can pass distance information which enables 3D color matrix metering.

jerl said:
AI-s and older lenses will not.

Depends on the camera. On my D700 I can enter the focal length and the maximum aperture for AI-S lenses. This enables color matrix metering (although I am not sure if this is the same as 3D matrix metering).

Yes, jerl, but there is (was?) a difference between Matrix metering and 3D Matrix Metering.

Any lens that has electronic contacts to transmit the focal length of the lens and maximum aperture can be used with matrix metering on modern Nikon cameras, so AF and later lenses will work. AI-s and older lenses will not.

I've done a search and can find no discussions on Nikon Rumors about what the technology that is used for the various Nikon lense designations actually does.

The only reason this is a question, is that I put my 1992 35-70/3.3-4.5 Nikkor Zoom lenses on my D7000, and realized that the D7000 allows 3d matrix metering.

From all that I'd read, 3d matrix Metering requires an AF-D level or later lense, which again from everything I've read the AF lenses I have got, is not. (As a note, all the photos I've taken include in the meta data the zoom length)

Either my research is wrong, and pre AF-D lense can do 3d matrix metering on the D7000, or some pre AF-D lenses, are in fact AF-D compliant.

Ok guys, what do you know ?