> The curves/histogram is very nice, but
>> unfortunately unuseable when embedding Adobe RGB. So this is a major
>> deficiency in my opinion.
It was a necessary evil to avoid IQA getting totally confused. So far as
embedding Adobe RGB 1998; I wouldn't worry. If Photoshop is configured
correctly it will flag up the profile mismatch when the file opens. You can
simply choose to allow the conversion to take place and all will be well.
Remember with Insight you are viewing and editing in monitor space; the fact
that you might choose to embed Adobe RGB has no bearing on what you see
within Insight Pro. Furthermore, good as Polaroid might have made Insights
colour space conversion engine or if they use Microsoft's it isn't likely to
be as accurate as the Adobe CMM.
> When I try to preset the black point and white point in the "auto curves
> correction under Preferences/Edit, these settings seem to have no effect on
> black pint and white point in the actual preview or scan. Maybe that doesn't
> work with Adobe RGB embedded either?
Same reason as curves - one or other but not both you and IQA :-)
> Anyway I now can't figure out how to adjust white and black point(with
> profile embedded) and all I can do to stretch the histogram a bit is to use
> the contrast, which seems wrong.
Disable the Embed Adobe RGB feature and all the features will be as you