The last several decades of technology improvement say that
you're wrong. We're not at the level of counting individual
photons yet, so sensors can get smaller without quality loss.
Actually we are. A cooled CCD often has noise levels in the low single digit photon counts.
Today the sweet spot gives us 6MP on the smaller sensor.Actually sensor site size does correspond to noise floor, and sensors aren't a certain number of bits (at least in any SLR camera sensor or not-toy-P&S sensor). The quanitization takes place off sensor.
Sensors can be made larger if you are prepared to pay the
vastly increased cost. Individual pixels can be smaller,
too; some of the current crop of 5MP cameras have sensors
that are considerably smaller (but are probably only 8-bit
sensors rather than the deeper one used in the *ist-D).
How many pixels do you need, anyway? A 25-megapixel sensorI did the math on this in the archives- it doesn't keep scaling forever (like RAM and MHz). Just cause we can make transistors small doesn't make the sites more efficient, nor does it make the wave property of light go away.
the same size as the current one is a couple of generations
away - we'll probably see that at affordable prices inside
five years.
THe one indisputable argument in favour of larger sensorsMake that two: noise.
But we're still not any good at making large chips, so big sensors are still gonna be mega-$.
-Ryan Brooks
