Digital BW, The Print

Jeff writes:

> When you shoot digital the resulting file is
> first generation!

So is a film scan.  Both film and electronic photography involve an analog
image capture and a conversion to digital form.  The digicam does this
inside the camera; for film, this is done later, with a scanner.

> Meaning, the original scene passes through just
> the camera lens and on to the capture chip. When
> shooting film the image passes through the camera
> lens on to the film and then when scanning a
> second lens is involved with possible imperfections.

In theory, this is a handicap; in practice, the quality of the optical
systems is so high that they do not limit the final image quality.
Furthermore, it's easier to design good scanner optics than it is to design
good capture optics, because the circumstances are much more constrained,
and focus and quality need only be maintained along a horizontal line or a
microscopic point, not throughout a rectangular image field.

An important and unavoidable principle that affects all systems that
interface with the real world, including imaging systems, is that it is
_always_ possible to design and build a completely analog system that will
match or surpass the quality of any digital system.  However, digital
systems usually provide a better price/quality ratio because they eliminate
the need for close tolerances in all system components except the analog
endpoints (image capture and image printing/display, in the case of
photography).

This is why audio CDs are so successful:  Although it's certainly possible
to build a completely analog system that blows CDs away, doing so is so
painfully expensive that virtually no one can afford it--audio CDs bring a
high level of quality to the average audiophile at a very low price.

So why isn't digital sweeping away film as CD swept away LPs?  For one
important reason:  CDs succeeded because the replaced the middle portion of
an analog system with a digital system, which is always a win-win situation.
Digital photography in contrast, is replacing one of the analog
endpoints--image capture--with a new system, while the digital part in the
middle remains the same.  Thus, "digital" photography is actually nothing
more than the adoption of a (potentially better) analog system, and since
analog systems improve only slowly, the advances of digital are much more
gradual.

Right now, digital is limited almost entirely by the analog electronic
sensor that replaces film.  As this sensor improves, digital will continue
to advance over film.

Most people understand digital photography only poorly, and the very
expression itself invites misunderstanding, since it hides the fact that
digital is actually introducing a new analog technology, not a new digital
technology.  This is why analogies between digital photos and audio CDs are
flawed, and it is also why, even after years, digital photography still
hasn't replaced film entirely--and it may never do so.

> Then there is chance that the film is not laying flat..
> and the the potential of grain aliasing.. and some curve
> or setting in the scanning driver software not being
> optimal.

This defect, and all the others you mention, are defects of analog capture.
But "digital" photography is just a change in analog capture, so while you
eliminate some of the problems with film, you introduce others with
electronic sensors.  Overall, electronic sensors _should_ ultimately
prevail, as they have more advantages than disadvantages when compared to
film.  But the situation is not nearly as cut and dried as the notion of
"digital" implies, and so you should probably not hold your breath.

> All these pitfalls are eliminated when shooting
> digital.

But others are added.  A few are inherent to electronic sensors and
unavoidable (e.g., thermal noise); others are just design choices that can
be fixed (e.g., use of a single CCD with a matrix color filter).

> I think it has to do with the fact that the vast
> majority of scans are less than perfect in some
> regard.

I agree.  Scanning is part art and part science, and it takes a long time to
learn to do it well (and a good scanner).  For this reason, probably 99% of
all film scans are dramatically substandard when compared to what would
actually be possible with a drum scanner and an expert operator.

The elimination of scanning is a huge advantage to digital photography.  But
the best film scans still leave digital images very much in the shade.