RE: filmscanners: Sprintscan 120 and new negative proile scheme

["Hemingway, David J" <HEMINGD@POLAROID.COM>]

Austin,
I think we may be talking by each other a bit. ICC profiles do contain
several LUTS including sophisticated 3d luts. These negative profiles will
be similar wich "ring around" sub sets to correct for specific conditions
such as over exposure, underexposure, high or low contrast, over and under
saturation. The bottom line here is we are testing the concept to determine
if it is of value. May be  or may be not. I guess we will see.
David
P.S. we won't force anyone to use them :)


> -----Original Message-----
> From: Austin Franklin [mailto:darkroom@ix.netcom.com]
> Sent: Wednesday, June 06, 2001 8:50 PM
> To: filmscanners@halftone.co.uk
> Subject: RE: filmscanners: Sprintscan 120 and new negative 
> proile scheme
> 
> 
> > Austin,
> > All scanning software characterises film in some way as an 
> attempt to get
> > you near where you want to be. You can still use your 
> individual artistic
> > talents to effect the final product.
> > In no scanner software of which I am aware will give you by
> > default the raw
> > data from the ccd.
> 
> David, raw data has nothing to do with "film profiling".  
> Setpoints have
> nothing to do with film profiling.
> 
> > The raw data fom the scanner is processed through a
> > matrix filter or profile.
> 
> What is a matrix filter?  The raw data from the scanner is 
> thresholded with
> the setpoints, then run through a LUT to correct for the 
> non-linearity of
> the CCD, then LUT'd again for the tonal curve adjustments you 
> make.  You can
> do the non-linearity correction before or after the setpoints 
> are applied,
> it doesn't matter.  This is all done on high bit data.  If 
> you are getting 8
> bit data, then the data is decimated from the full span of 
> the data between
> the setpoints, down to 8 bit data.
> 
> > The goal of these profiles and matrix filters is to recover 
> correctly as
> > much information from the film as possible, removes the 
> base, do general
> > corrections based on what it knows about the ccd/scanner 
> system and film.
> 
> Er, right.  But you don't have to profile the film to do 
> that.  The CCD is
> already "profiled" in the firmware of the scanner.
> 
> I still disagree with film profiling.  How come the Leafscan has given
> perfect scans for the past 10+ years with no film profiles?
>