Waht is 'Improved color correction' in Vuescan .73 and .75

Hello,

does anyone (preferable Ed ;-) now, what exactly the 'Improved color
correction for film' in vuescan versions 7.6.73 and 7.6.75 means? Is it
a different film base color processing?

--
Erik Krause
Digital contrast problems: http://www.erik-krause.de/contrast

Erik Krause <erik.krause@gmx.de> wrote in message news:<MPG.1a80e83fb2125d8498a38e@ID-18456.user.dfncis.de>...
> Hello,
>
> does anyone (preferable Ed ;-) now, what exactly the 'Improved color
> correction for film' in vuescan versions 7.6.73 and 7.6.75 means? Is it
> a different film base color processing?

One thing I notice, having just upgraded from 7.6.53 to 7.6.75, with
the earlier version, and for the first time, I ceased having an uptick
at dark end of histogram when working with raw files of Tri-X, even
with bp at 0. Sometimes there was even a space.

However, with the 7.6.55, the uptick is back, BUT, I can almost
exactly replicate the 7.6.53 histogram if I simply tick "lock film
base color", and manually set all 3 of the additional boxes in the
color tab (lock film base red/green/blue) to value of 1.0

Note, I'm not going through the advanced workflow steps, just forcing
it as I described above.