RE: filmscanners: Vuescan blue anomaly

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

I have to agree with Rafe. Autolevels can be a very distructive tool. When I
first started scanning it used it all the time but after seeing the trouble
it can cause. I NEVER us it.
David

> -----Original Message-----
> From: rafeb [mailto:rafeb@channel1.com]
> Sent: Wednesday, July 25, 2001 3:35 PM
> To: filmscanners@halftone.co.uk
> Subject: re: filmscanners: Vuescan blue anomaly
> 
> 
> At 12:41 PM 7/25/01 +0000, Lynne wrote:
> >Rafe wrote:
> >
> >>"Auto Levels" is a bit of a sledgehammer approach to
> >>color correction.  Not very subtle, and quite often
> >>wrong.
> >
> >Yes, but it's quick. When you're working on images that 
> differ greatly in 
> >subject, film, time of day, and exposure (and I always am), 
> it saves a lot 
> >of time to get color casts, levels, etc. out of the way 
> right away so you 
> >can do the *real* corrections. :-)
> 
> 
> I disagree with the last part of that paragraph.  
> By the time "Auto Levels" is done with your image, 
> it may have mangled it beyond repair.
> 
> Go ahead and use it if you're in a hurry -- most 
> of the time, it does more or less the right thing. 
> 
> A far better approach, IMHO, is to set the black 
> point/white point with the droppers in either the 
> Curves or Levels tool.  There, you have much more 
> control -- 
> 
> * You can set black point to any RGB value you like
> * Ditto for white point
> * You can *place* the black point where it's most 
>   appropriate within the image.
> * Ditto for white point.
> 
> The latter approach only takes a bit longer than 
> "Auto Levels" but allows much greater control, with 
> little chance of losing critical image data.
> 
> "Auto Levels," IMHO, gives far too much freedom 
> to the machine -- the freedom to screw up my photo. 
> No thanks... <g>
> 
> 
> rafe b.
> 
>