Re: To David Soderman: A Little Test

[rafe.bustin@xxxxxxxxxxx]

On 8 Apr 2002 at 22:33, Kennedy McEwen wrote:


> It was incompetent negligence beyond belief that a Nikon engineer 
> expected the same calibration of one CCD to apply to all three to an 
> accuracy of more than 14-bits!  (Since this is a systematic error 
> extending over complete scan lines the correction necessary to ensure 
> that mismatch is imperceptible is considerably greater than the noise 
> floor of the scanner).
> 
> I still have trouble accepting that this aspect of the design wasn't 
> done by the Nikon tea-lady!    :-)


This particular theory was put forth by Ed Hamrick, 
and it was (and remains) difficult for me to accept.

The much-dreaded banding on the LS-8000 is highly 
regular and periodic.  Furthermore, it is in a direction 
parallel to the CCD array itself (ie., perpendicular to 
the scan motion.)

On a color image, it affects at least two of the three 
color channels (green and red mostly.)

I just don't see how this alleged calibration issue can 
lead to the banding that I and others have observed on 
the LS-8000.

Furthermore, if this were a firmware issue, why wouldn't 
Nikon have issued a firmware update by now to deal 
with the problem?

I am much more inclined to believe that this is a 
mechanical issue, perhaps related to stepper motor 
resonance.  There is no doubt that the LS-8000 is 
the loudest film scanner I have ever used.


rafe b.

-
Turn off HTML mail features. Keep quoted material short. Use accurate
subject lines. http://www.leben.com/lists for list instructions.