High ISO only in low light, or???
I use 400ISO for portraits, the sizes I print/see there's absolutely no difference from ISO100, if I'm going to shoot handheld and lighting may get a bit low (interiors, even at daytime). ISO800 is already stretching it a bit (D80). For macro and landscapes I use ISO100, since one needs more headroom for PPing.
'Had my camera ready again. There was a jasmine scent at the roof's end. I photographed the scent.'
Manoel de Barros - Brazilian poet