Re: filmscanners: Scan Dual II on Mac platform

[Arthur Entlich <artistic@ampsc.com>]

Berry Ives wrote:

> on 2/24/01 9:00 AM, Tony Sleep at TonySleep@halftone.co.uk wrote:
> 
> 
>> On Thu, 22 Feb 2001 19:08:18 -0700  Berry Ives (yvesberia@earthlink.net)
>> wrote:
>> 
>> 
>>> 4.  I had a lot of trouble trying to get neutral gray in the background
>>> out-of-focus area of one image (Fuji S400).  I ended up accepting some
>>> magenta surrounding the darker grays that came out okay, and then around the
>>> magentas I had subtle halos of cyan. ...

I suspect you might be seeing a problem which is typical on my S-20 
scanner, and is basically out of alignment filters or motor slippage or 
something, that causes color fringing.  It may be more obvious in out of 
focus areas because there isn't much detail there to hide it, or it 
could be posterization of certain gray levels, or simply a poor gray 
scale that shifts one way on some grays and the other on others.   To 
check to see what's causing this:

1) scan a gray scale or some gray patches in RGB mode, and see if they 
shift to tinted tones.  You have to scan in color mode, or the driver 
will simply return only gray scale data to your monitor and you won't be 
able to tell anything.

2) Take a black and white neg and mount it in a slide mount and scan as 
a color slide, or if your scanner software allows, scan a frame from a 
black and white neg strip and scan it as a color slide strip.


Look closely to see if you see color (beyond random noise).  If you are 
seeing color fringing or bars running through the image, the filters are 
likely out of alignment, the stepper motor or transport slipping or the 
optics have color defects.  If you see different colors in different 
gray values, you are probably seeing bad programing in the driver, or 
color imbalance in the CCD sensitivities or filtering, of focal 
differences caused by the filters within the scanner.

>> 
>> Convert to greyscale in PS. Then convert back to RGB. Brutal, but neutrality
>> assured - unless it's a printer problem :)
>> 

Yes, this confused me as well.

Art