Minimum pixel size

On Sat, 31 Jul 2004 10:43:56 +0000 (UTC), Matti Vuori
wrote:

Alfred Molon wrote in
m:

Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?

A CCD doesn't have pixels. They only exist after calculation from the
sensor information.

I am in awe of the clarity of your reasoning and the lucidness of your
explanation.

On Sat, 31 Jul 2004 10:43:56 +0000 (UTC), Matti Vuori
wrote:

Alfred Molon wrote in
m:

Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?

A CCD doesn't have pixels. They only exist after calculation from the
sensor information.

I am in awe of the clarity of your reasoning and the lucidness of your
explanation.

On Sat, 31 Jul 2004 10:43:56 +0000 (UTC), Matti Vuori
wrote:

Alfred Molon wrote in
m:

Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?

A CCD doesn't have pixels. They only exist after calculation from the
sensor information.

I am in awe of the clarity of your reasoning and the lucidness of your
explanation.

"Alfred Molon" wrote in message
...

Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?

It's hard to understand how a pixel could usefully be smaller than a
wavelength of light.

"Alfred Molon" wrote in message
...

Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?

It's hard to understand how a pixel could usefully be smaller than a
wavelength of light.

"Alfred Molon" wrote in message
...

Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?

It's hard to understand how a pixel could usefully be smaller than a
wavelength of light.

Indeed it will be very hard to get a lens to produce a blur circle
smaller than the wavelength of the light being imaged. Thus it is
unlikely to make any sense trying to make a chip with a resolution any
smaller than about 0.65 microns (red light).

For some military purposes it may be reasonable to employ UV imaging,
and go slightly smaller, but the pictures would not be very useful for
consumer cameras.

Joseph Schutz wrote:

Of course 1 micron is possible, but noise is the key point.
It is also worth mentioning that lens resolution would also need
to be very good, which would cost more.

You can assume that the camera companies trade off the cost
of the lens verses the cost of the sensor. I would imagine relatively
small sensors give the lowest total cost for both.

The high end cameras have lower noise because of larger pixels.
This costs more for the system.

Joe

"Alfred Molon" wrote in message
...
Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?
--

Alfred Molon
------------------------------
http://groups.yahoo.com/group/Olympus_405080/
Olympus 5050 resource - http://www.molon.de/5050.html
Olympus 5060 resource - http://www.molon.de/5060.html
Olympus 8080 resource - http://www.molon.de/8080.html

--
Don Stauffer in Minnesota

webpage- http://www.usfamily.net/web/stauffer

Indeed it will be very hard to get a lens to produce a blur circle
smaller than the wavelength of the light being imaged. Thus it is
unlikely to make any sense trying to make a chip with a resolution any
smaller than about 0.65 microns (red light).

For some military purposes it may be reasonable to employ UV imaging,
and go slightly smaller, but the pictures would not be very useful for
consumer cameras.

Joseph Schutz wrote:

Of course 1 micron is possible, but noise is the key point.
It is also worth mentioning that lens resolution would also need
to be very good, which would cost more.

You can assume that the camera companies trade off the cost
of the lens verses the cost of the sensor. I would imagine relatively
small sensors give the lowest total cost for both.

The high end cameras have lower noise because of larger pixels.
This costs more for the system.

Joe

"Alfred Molon" wrote in message
...
Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?
--

Alfred Molon
------------------------------
http://groups.yahoo.com/group/Olympus_405080/
Olympus 5050 resource - http://www.molon.de/5050.html
Olympus 5060 resource - http://www.molon.de/5060.html
Olympus 8080 resource - http://www.molon.de/8080.html

--
Don Stauffer in Minnesota

webpage- http://www.usfamily.net/web/stauffer

Indeed it will be very hard to get a lens to produce a blur circle
smaller than the wavelength of the light being imaged. Thus it is
unlikely to make any sense trying to make a chip with a resolution any
smaller than about 0.65 microns (red light).

For some military purposes it may be reasonable to employ UV imaging,
and go slightly smaller, but the pictures would not be very useful for
consumer cameras.

Joseph Schutz wrote:

Of course 1 micron is possible, but noise is the key point.
It is also worth mentioning that lens resolution would also need
to be very good, which would cost more.

You can assume that the camera companies trade off the cost
of the lens verses the cost of the sensor. I would imagine relatively
small sensors give the lowest total cost for both.

The high end cameras have lower noise because of larger pixels.
This costs more for the system.

Joe

"Alfred Molon" wrote in message
...
Is there a lower limit to pixel size, i.e. could pixel size in a CCD go
to 1 micrometer and below (if we disregard noise issues for a moment) ?
--

Alfred Molon
------------------------------
http://groups.yahoo.com/group/Olympus_405080/
Olympus 5050 resource - http://www.molon.de/5050.html
Olympus 5060 resource - http://www.molon.de/5060.html
Olympus 8080 resource - http://www.molon.de/8080.html

--
Don Stauffer in Minnesota

webpage- http://www.usfamily.net/web/stauffer

In message ,
David Littlewood wrote:

However, to take this as a practical proposition overlooks the fact that
there is a hard limit to how much a lens can resolve: diffraction. This
means that any lens, even a perfect one, will produce not a single point
image (of a single point object) but a slightly blurred spot. The size
of this spot depends on the relative aperture of the lens (the
f-number). Any attempt to resolve below this point will just make the
fuzzy dots bigger.

It may not be efficient, but if you out-resolve the lens by a margin,
then bayer demosaicing becomes nearly artifact-free, no AA filter is
necessary, and pixel-level noise can be totally written off because you
know for a fact that it is not image detail. You can remove the noise
with a low-pass filter that doesn't affect image detail. The question
is whether there will be enough dynamic range left after the noise of
the tiny sensels.
--


John P Sheehy