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RE: filmscanners: Digicams again was Re: filmscanners: Minolta DiMAGE Scan & Dimage 7 camera
At 07:42 AM 6/30/01 -0600, Frank Nichols wrote:
>I understand your hesitancy, however, you make several assumptions that I
>1. SNR remains at todays levels.
>2. Sensitivity remains at todays levels.
>3. The array would be small - why not a 4" x 6" with a 10x increase in
>density? that would require about 1.5GPixels (If I didn't slip a decimal
>point.) Or even an 8x10?
>In RAM/CPU technology - a simliar technology - the increase over the years
>has not just occurred in dimensions, but in performance (speed), power
>I will stand by my prediction and be here in 5 years to say I told you so!
The improvements in silicon technology are mostly
improvements in lithography (smaller features,
enabling higher densities) and placement of dopants
in the silicon (in all three dimensions) via ion
implantation. Also, better ways to clean up after
masking steps, using plasma etch instead of wet
There really haven't been that many revolutionary
developments in silicon -- mostly evolutionary.
At the silicon level, you're still moving electrons
and holes across junctions and through FET channels.
>From time to time, folks figure out clever new
technologies that simply make older problems
irrelevant. Delta-sigma A/D converters come to
mind. There was a time when all A/Ds used resistive
networks, and these created an inherent upper-limit
on resolution (around 12 bits.) Newer A/Ds simply
scrap that approach to achieve real resolutions
of 16 bits or more (at high sampling rates) or even
up to 20 bits, where bandwidth is not an issue.
In terms of CMOS or CCD sensors, I remain convinced
that they need to be physically larger before they
become interesting to some of us "purist" photographers.
That may yet happen, but only if yields improve. Or,
alternatively, firmware steps in to deal with the large
number of defective pixels.