Low lux colour CMOS cameras?

[Daniel Kelly (AKA Jack)]

Hi again,

Does anyone know of a miniature color PAL CMOS camera sensative to 1 Lux or
less?

I have found very sensitive colour CCD cameras and fairly sensitive B&W CMOS
cameras but no sensitive CMOS cameras.

Thanks in advance,
Jack

 

[Daniel Kelly (AKA Jack)]

One more question:

Am I getting confused by the physics? In other words, if I have a white
light source of, say, 1W, will this be detected with the same efficiency by
both a 3lux colour camera and a 1lux B&W camera? I ask this because I now
know that lux is a psychometric unit - it takes into account the efficiency
with which the human eye sees different wavelengths.

See:

http://www.physlink.com/Education/AskExperts/ae409.cfm
http://en.wikipedia.org/wiki/Lux

Thanks,
Jack



"Daniel Kelly (AKA Jack)" <d.kellyNOSPAM@NOSPAM.ucl.ac.uk> wrote in message
news:c8deet$fmo$1@uns-a.ucl.ac.uk...

Hi again,

Does anyone know of a miniature color PAL CMOS camera sensative to 1 Lux
or
less?

I have found very sensitive colour CCD cameras and fairly sensitive B&W
CMOS
cameras but no sensitive CMOS cameras.

Thanks in advance,
Jack

 

[Jan Panteltje]

On a sunny day (Tue, 18 May 2004 17:43:57 +0100) it happened "Daniel Kelly
\(AKA Jack\)" <d.kellyNOSPAM@NOSPAM.ucl.ac.uk> wrote in
<c8deet$fmo$1@uns-a.ucl.ac.uk>:

Hi again,

Does anyone know of a miniature color PAL CMOS camera sensative to 1 Lux or
less?

I have found very sensitive colour CCD cameras and fairly sensitive B&W CMOS
cameras but no sensitive CMOS cameras.

Thanks in advance,
Jack
CMOS cameras (or rather CMOS sensors) have a problem with low light.

One of the problems is the difference in gain of the pixel amps.
On low light CMOS cameras display all pixels in a different brightness.
This is a little compensated for by on chip calibration of the individual
pixel amps.
The other factor is exposure time.
Increasing exposure time may help somewhat.
Reason of all this is tolerances in the CMOS fabrication process IIRC.
There are some papers on this on the web.
JP

 

[Graham W]

"Daniel Kelly (AKA Jack)" <d.kellyNOSPAM@NOSPAM.ucl.ac.uk> wrote in
message news:c8deet$fmo$1@uns-a.ucl.ac.uk...

Hi again,

Does anyone know of a miniature color PAL CMOS camera sensative to 1 Lux
or
less?

The Philips ToUCam II Pro webcam is specced at 1 Lux but it *doesn't* use
a CMOS sensor. As others have said, CMOS does not work well at low
light levels.


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[Ian Stirling]

In sci.electronics.design "Daniel Kelly \(AKA Jack\)" <d.kellyNOSPAM@nospam.ucl.ac.uk> wrote:

One more question:

Am I getting confused by the physics? In other words, if I have a white
light source of, say, 1W, will this be detected with the same efficiency by
both a 3lux colour camera and a 1lux B&W camera? I ask this because I now
know that lux is a psychometric unit - it takes into account the efficiency
with which the human eye sees different wavelengths.

snip quoted message incorrectly placed at bottom

No.
Broadly speaking, it'll be three times dimmer in the 3 lux camera.
You need a camera several times more sensitive in order to have the
same sensitivity when you convert it to a colour one by putting dyes
above the pixels in various colours.
The 1 lux camera may also be sensitive to infrared, which helps
sensitivity, and does not have losses through dyes to contend with.