hi,
i think there are two things here:
* most probably the ixus 850 has only one aperture
at all like most other ixuses and uses an nd-filter
to simulate another one (but because it is at the
same aperture there is no influence on dof - depth
of field) - so there is nothing to set anyway
* the sensor chips in p&s digitcams are so small,
that you will get real dof only in macro situations,
for everything else you will need something with
a bigger sensor (like a dslr) or go back to film -
both combined with a fast prime lens or for smaller
targets a medium fast tele should give you what
you are looking for
* you may try to fake dof in photoshop using the
lens blur filter with a layer mask which is based
on the distance to the objects - there are some
tutorials about this on the net like here
http://photography-on-the.net/forum/showthread.php?t=102294good luck and best wishes - image13
