Vuescan film vs scanner profiling

[jaydub]

I have a Minolta 5400 scanner that I am sending my chromes through.
A while back I bought the IT8 targets from wolf faust and followed the
vuescan directions for profiling. What confused me then and still
confuses me some is exactly what sort of profiling I should be
doing.

In other words, what is the difference between the profile scanner
option and the profile film option? I assume in both cases I would
be using the same IT8 target slides to profile with. My goal is
to get the most accurate color possible when outputting from
vuescan to work in photoshop.

 

[Bart van der Wolf]

SNIP

In other words, what is the difference between the profile
scanner option and the profile film option? I assume in both
cases I would be using the same IT8 target slides to profile
with.

No, that's not correct. Profile scanner does just that, it creates a
scanner profile for scanning a particular type of film dye (= film
type/family specific). Each scanner's lightsource has a particular
color (which can change as it ages) that shines through a multilayered
color filter (film), which has a specific absorption/transmission
characteristic per wavelength, which reaches a sensor with specific
color sensitivity for specific wavelengths. Applying those multiple
changes to the spectral emission of the lightsource, will allow to
adjust the way the scanner sees color, because it has been measured
what the colors should look like and those measurements accompany your
unique IT8 target.

A film profile is made by shooting a reflective IT8 target on a
particular type of film you use, under a particular lighting (e.g.
mid-summer day at noon under a cloudless sky). Since the target's
colors are known because they were measured under specific lighting
conditions, and the changes that the scanner adds are known from its
profile, the influence of the film/lighting can be eliminated.

Bart