[filmscanners] RE: Pixels and Prints

["Austin Franklin" <austin@darkroom.com>]

Hi David,

> > How can a scanner have superior spectral response to a Bayer camera?
>
> Unless all the sensors seen the same thing, they aren't seeing the same
> thing.  In a Bayer pattern sensor, each sensing element is seeing
> different
> light, unless there is a filter over the sensing elements that
> provides that
> function.
> <<<<<<<<<<<<<
>
> Here's where we disagree: I don't see the lower spatial
> resolution for color
> affecting the spectral resolution for color. The actual measurements are
> identical (other than being first generation in digital, second in scans).

Why do you keep bringing up 1st/2nd hand?  The Bayer pattern image is in
fact 2nd hand as well.  It is in fact a resampling because of the Bayer
pattern reconciliation, so it, too, is a second generation image.  If you
had the raw data, it would do you no good.  So, I don't buy into this 2nd
generation/1st generation argument.

Also, with the Bayer pattern sensor, if a detail has a predominance in a
particular color, and that falls on the sensor that isn't of that color,
it'll be missed.  That isn't as significant as it may sound, but it is
significant, and reduces the fidelity of the overall system.

> So for features large enough to see, the Bayer camera is providing full
> color measurement. And with a lot lower noise than scanners.

Lower noise?  What you are calling lower noise is dubious.  "Perceived"
lower noise does not mean higher fidelity.  How do you know it's lower
noise?  Have you actually done a comparison of it to the original image
scene to see what was noise and what was not?  The Bayer pattern
reconciliation introduces substantial noise, it has to by nature.  Also,
lack of detail make it appear as less noise.  Again, cartoons appear to have
very little noise, and they have no detail.

> >>>>>>>>>>>
> Film also has a higher image density capturing ability, which current CCDs
> do not, and as such.
> <<<<<<<<<<<<
>
> "image density capturing ability"???
>
> If you are talking about dynamic range or latitude, the tests
> I've seen show
> the dSLRs superior to slide film.

Dynamic range (NOT latitude, those are two entirely different things).  I
was talking about negative film, and no, there is no digital sensor that has
the overall ability of negative film.

> Also, there's the issue of noise. Scanned film is a lot noisier
> than direct
> digital capture.

Not necessarily true.  Some may be, but that's due to poor
film/scanner/development, as well as the "perception" that digital has less
noise, when, in most cases, it isn't really less noise, but reduced
fidelity.  It also depends on how you measure noise, and what you classify
as noise.  It's simply not a 1:1 comparison.


> Just the noise problem alone makes scanned film
> problematic
> for color reproduction: the bit depth after the noise is much less than
> digital.

My experience contradicts this.

BTW, the 35mm camera/lenses you use for your scanning would be.... ;-)

Regards,

Austin

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