I have 2 D800s and unfortunately they only work in studio....

I can tell you pretty well ! It all started in 1983 when the Nikon FA model came out and started to

use the first matrix metering system....

A few years before that they started to collect a database of thousands of pictures and analysed

how the image was exposed and how contrasts were and so on.......

When Nikon moved to autofocus eventually they used that database and built a sort of matrix metering into the autofocus and made it more reliable that way.....

The database was augmented to a metering AND color AND AF database.....

If you look at the blockdiagram of that new 91K scene recognition system you will see

that the results are biased according to tne analasys of millions of pictures that were taken with pictures that were taken

In your case of tungsten versus daylight its very logical because in 90 % of the cases tungsten is

indoors and you need more depth of field on your foreground and the backround in closed rooms is

much nearer.....thats amatrix style metering.... ! As I said in my thread in order to put the focus exactly on the subject you need to use a non matrix AF metering... the closest is afs with "S"

and focus hold....!

Peter