Hi Lon, Search the internet for "Bayer Interpolation". Basically, there is a.
Filter in front of each fixel. The fiters vary in colors (3 or 4) which.
Means that each pixel captures part of a full-color pixel. The Bayeer Interpolation is the technique used to guess the missing colors. On the other hand, Foveon pixels capture colors by stacking one sensor.
Under each other for each color, the same as film layers. The result have errors too known as crosstalk which is when colors meant from one layer end-up in the wrong layer. This occurs in film and on Foveon sensors. In the film industry, people use color-grading software such as Discreet Lustre to store the correct colors to film. Even if one argues that crosstalk can be solved better than Bayer Interpolation, the major obstacle seems to be scalabilty. Foveon sensors have yet to be produced the enough megapixels to compete with high end Bayer sensors.
CCD and CMOS has nothing to do with Foveon vs the rest. Foveon approach have 3 layers of photosites instead of only one as the rest, who uses a colored array of filters in a Bayer pattern. Both approachs have their drawbacks. Foveon approach captures all color info in every pixel, at the expense of reduced sensitivity and some strange colors, as the silicon layers doesnt filter the colors in the same way the eye perceive them. Bayer patterns have a more faithful color reproduction, and increased sensitivity, at the expense of color moire if no antialiasing filter is used, or reduced resolution if it's used, but the loss in resolution isn't as dramatic as 3x, but near to a 2x one, so a 3MP (9MP total) Foveon sensor is similar to a 6MP Bayer pattern one.
CMOS vs CCD is just how the sensor is made, techology wise. Actually I think Foveon uses CMOS, but Im not sure. All non Foveon sensors CCD or CMOS, use a Bayer pattern. Guillermo..
Foveon sensors are CMOS only, that is the nature of the silicon.
Process used. I agree, the original question seems to imply that non-Foveon sensors.
Are all CCDs. As Guillermo said, it is not true. Low-end cameras tend.
To use CCDs because they are cheaper to make. CMOS sensors are more.
Expensive but have advantages including speed at which they can be.
Read. - Itai.
Low-end cameras tend.
To use CCDs because they are cheaper to make. I think the exact opposite is true. CCDs are more expensive to make due to the specialized setups required in it's manufacture. CMOS is relatively cheaper to manufacture, since it can be manufactured on a production line where other computer chips are manufactured. However, due to the expense associated with manufacturing CCDs (and the large sensor sizes required in DSLRs), manufacturers seem to be focusing their attention to CMOS sensors, thus enabling CMOS sensors to improve a lot and quite a few of them are now getting better than most CCDs. Canon is a case in question where their CMOS sensors are truly exceptional due to the processing they are able to do within each micro-lens. The really top-end cameras like Mamiya etc., still use CCDs exclusively, but obviously they cost well over 10-20K...
CMOS sensors are also used in very low-end video and still capture applications such as webcams, cellphone cams, toys, etc. The advantage to them in addition to being fabricated on standard CMOS production lines is that support and processing circuitry can be integrated onto the same chip as the sensor, making for very inexpensive, compact and low power solutions. Maxx..