vuescan and clipping whites - any help graciously accepted.

Archived from groups: alt.comp.periphs.scanner (More info?)

Hello group

Scanning noobie here looking for some help. I have waded through two
books but am still unclear on a few matters. Perhaps someone who is
familiar with vuescan could answer this best.

All of vuescan's colour defaults (manual, neutral, white point, etc)
come with a suggested white clipping that is higher than 0%. Black point
percentage is 0%, but white point percentage is 1%. By my understanding,
that necessarily means that that you lose some hightlight detail.
Everything in the last percentile of the highlights will be blown out.

My questions (misunderstandings?) are two fold.

First of all, this default of 1% looks a hell of lot more than 1% on
their histogram graph. They little triangle beneath the histogram looks
like it's moved in to about 10% rather than 1%. Why is this so?

Secondly, I do not understand why you'd want to clip any white at all?
Surely by blowing out the highlights you are losing detail in the
process, which is critical if I'm scanning for printed output?

I am a bit lost in all of this - any help will be graciously accepted.