Digital BW, The Print

The 8000 has two scanning speeds that have been named in an unfortunate way.
In what Nikon calls a "normal" scan, the film is scanned at high speed,
thanks to 3 linear CCDs--unique among Nikon's scanners as far as I know.  In
Nikon's "superfine" mode, only one CCD is used, but the scan takes three
times longer (this is how their other scanners normally work).  Banding only
occurs in the high-speed mode and only in scans where there are transitions
between nearly clear film and nearly opaque film (as on a Velvia slide of a
contrasty subject in direct sunlight, for example).  Only a small fraction
of my scans have shown enough banding to justify a rescan in low-speed mode
(there is never any banding in the slow or "superfine" mode).

It's unfortunate that Nikon calls these modes normal and superfine, because
they are really fast and slow modes.  The fast mode is fast, but you do run
the risk of banding in some cases because the CCDs are never perfectly equal
in their signals.  The slow mode is slow, but since only one CCD is used,
banding is not possible.  The slow mode does not produce finer scans than
the fast mode, at least not in the sense of resolution or anything; it just
prevents banding.

In other Nikon scanners, the "slow" or "superfine" mode is the only mode,
since there is only one CCD.  So actually the "superfine" mode should be
considered "normal," and the "normal" mode should be considered "fast."  By
naming them incorrectly and chosing the wrong defaults, Nikon created the
impression that the scanner has an overall problem with banding, which is
not the case.  In fact, banding is only an issue with high-speed (three CCD)
scans, and even then it is rarely perceptible (in my experience).

The banding in the high-speed mode is the result of unequal calibration of
the three CCDs.  I'm not sure why Nikon doesn't have a better way of
calibrating them internally so they always match perfectly.  In any case,
high-speed scans are entirely satisfactory the great majority of the time,
even on Velvia.  (I don't recall ever seeing banding on negative scans, with
their relatively tame density, although I suppose it's theoretically
possible.)

----- Original Message -----
From: "somax711" <bprichard@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Friday, September 12, 2003 00:46
Subject: Re: [Digital BW] Nikon Coolscan 800 120 film holder


> Any problems with banding with the Coolscan 8000?  I was in the
> market for one last year, but found a lot of posts about problems
> with banding at high resolution scans.