RE: filmscanners: VueScan Histogram

["michael shaffer" <rarewolf@roadrunner.nf.net>]

Philip writes ...

> *From my observations if you just scan with the WP at 0.1
> as default, you can compress the tonal values rather than
> making sure the image ocupies the full range available.
> If your image allows a WP of say 0.4 just before clipping
> then the available range isn't wasted in the 0-0.4 area*
> ...

  That's my impression as well.  For example, any given photo depending
exposure and subject, the scan may be asked to include "white without
detail" into the histogram ... which may sacrifice levels for "white with
detail".  I believe as you force the histogram to include the former and
play with the Wp=0-.4 region, you'll notice significant effect on brightness
(or apparent gamma).  Once you set Wp so as to exclude most "white w/o
detail" you'll see less effect ... and it is here where you should probably
set the Wp.  A good histogram presentation, which might display a "small
bump" due to specular highlights would be beneficial, and reduce time wasted
at guessing.

shAf  :o)