Getting too dark pictures with Vuescan - can't change expo..

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

How can I increase exposure in Vuescan to open up shadow detail in
dark photographs?

I have tinkered for hours with this without success. Tried
checking/unchecking Lock image color, cropping the original, masking
off white areas with black paper, increasing number of passes, etc.
Read the help too.

Of course I can lighten the scanned file in software, but that just
gives gray shadows without any detail.

The Epson software that came with the scanner does a much better job
of this. Lighter images, detail in the shadows. I don't get it... I
have heard such good things about VueScan. It's supposed to give me
control, isn't it?

I need to save the scans as Raw files. The Epson software doesn't
allow that AFAIK.

Perfection 3170 photo, Vuescan 8.1.16, Win XP.

By the way, I used to get better results with an older Perfection 1200
and Vuescan 8.1.12 - lighter scans and better shadow detail, although
still no way to control exposure that I could find.

Alfonso