filmscanners: Vuescan - A few technical questions

["Joel Nisson" <jdn@bird9.com>]

For Ed Hamrick (most likely):

I just purchased Vuescan and have a few technical questions:

1.  In the Color balance tab, what is the difference between "Neutral" and
"Auto Levels?"

2.  Also in Color balance, does "White balance" assume that the lightest
object in the image is white?  Can it be used if there are no white objects
in the frame?

3.  When should Options/Long scan not be used.  I assume it is useful for
bringing out shadow detail, but it seems to me that it would always be good
to use, since "auto exposure should control blowout.  Are there situations
where it might cause problems?

4.  How does Vuescan calibrate the scanner?  When I pull down "calibrate"
from the device menu, nothing seems to happen.  Don't you need an IT8 target
or equivalent to calibrate a scanner?

Thanks.

Joel Nisson
jdn@bird9.com