Fill Flash, Nikons Achiles heel Can anybody advise me please??

1.  Don't attempt to use P mode when you want fill light--  the results are unpredictable with flash set to any of the TTL modes.

2.  If you really want to use P mode, then a work around is to set the SB-900 to Auto mode.  The SB-700 doesn't have an Auto mode.

3.  Fill light works more predictably in A mode and M mode with flash TTL

4.  If you want to darken the background in A mode, then you have to lower camera exposure compensation and raise exposure compensation on the flash the same amount.  On the D800 camera and flash compensation are linked.   Therefore if you lower camera exposure compensation by -3 for example to darken the sky, then you have to raise the flash compensation by +3.  This is a pain.

5.  M-mode wins in the end because as many have stated, you can control the background with exposure speed, and the TTL or Auto flash will automatically take care of exposing the subject.  This is a lot easier than adjusting two exposure compensation settings as necessary in A-mode.  M-mode is not a return to the 1960s as some have stated, since you are still using TTL or Auto for the flash exposure.

Some have said that the exposure compensation linkage problem is solved in the D4 but I don't have one to test.

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==Doug