McLeod wrote:

Does anyone understand what are the mechanics behind the ISO settings
for RAW images?

Yes, I understand them. At least for the Canon 1D Mark II: there are
three buttons, a finger wheel, and a thumb wheel. Maybe the Nikon D70s
has the Telepathic Adaptor which can lock onto the mind of the
photographer, thus dispensing with these crude mechanical implements?

I think the poster was asking a more generalized question than you
responded to, but hey, who am I to stop you from making a jerk of
yourself.

You "think"?

Usually the lowest ISO setting of your digital camera is going to be
where you get the best picture with the lowest noise. Higher settings
are amplified, I believe, so noise is increased.

You "believe"?

They are only in increments of 100, 200, 400 to remain reciprocal with
shutter speed and aperture settings.

Well, you have offered two speculations and one error of fact. And you
accuse me of making a 'jerk of myself' for correctly answering his
question as written? Nitwit.