You already got a couple of answers to the identical copy of
this you posted on the 30th of July.

    You *won't* get e-mail answers -- you need to read the
newsgroup.

    My apologies if your news server isn't carrying the newsgroup,
so you aren't seeing *any* of the answers, or if your news server has
such a short expire time that the answers have allready been expired
before you get back to the newsgroup.

    The basic answer is that it will work in manual or "auto" mode,
but not with the fancy ttl metering where the camera tells the flash
everything that it needs to use.  I presume that it would work on older
film cameras, like the Nikon N90s, but because the sensor's reflectance
is *very* different from that of film, the technique in the N90s
(metering light bounced off the film during exposure) won't work, so the
SB-600 and SB-800 flashes do a pre-exposure "metering" flash, and
determine how much light reaches the camera from the flash (in different
zones of the image), and adjusts the flash output accordingly.

    So -- if you're willing to take test shots in a carefully set up
shot, the S-24 will do for you.  If you want to take candid shots (and
are willing to live with the flash betraying that you're shooting), you
will probably want the SB-600 or SB-800.

    Enjoy,
        DoN.