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Thread: CMOS or CCD?

  1. #1
    JerChan
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    Default CMOS or CCD?

    What is the difference between a CMOS sensor, like those in the Canon D60 and the CCD sensor in the FujiFlim FinePix S2 Pro?

    I've seen photos taken with the FinePix S1 in print and they were crisp clear with vivid colors right down to the detail.

    Have yet to see a D30's or D60's photos in print.

    Any difference between CMOS and CCD? How would the difference be best described?

    Was told that CCD is better then CMOS. How true?

  2. #2
    Midnight
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    Default Re: CMOS or CCD?

    Originally posted by JerChan
    Any difference between CMOS and CCD? How would the difference be best described? Was told that CCD is better then CMOS. How true?
    The technical differences between CMOS and CCD image sensors are somewhat complicated to describe, but basically the very general idea is that CMOS sensor arrays allow the input signal to be read (i.e. scanned and amplified) directly from each individual pixel, whereas the input signals in CCD sensor arrays are read by 'shifting' the charges across the chip. In a sense, CMOS works in a manner similar to direct random access memory in computers, and in fact it is indeed used as a limited form of storage in computers.

    Technical details aside, the key difference between CMOS and CCD sensors is that CMOS sensors are much cheaper to manufacture and require less power than CCDs. However, CMOS sensors have traditionally been plagued with poorer image quality (especially in terms of noise) and lower resolution compared to CCD sensors. More recently, however, CMOS sensors have improved tremendously in their performance (many high-end D-SLR bodies now use them), and now it is anticipated that CMOS sensors will eventually overtake CCD as the sensor technology of choice for digital imaging.

  3. #3

    Default

    And of coz, CMOS is a much newer technology than CCD. Naturally, I'll expect it to take some time to develop.

    But with the D30, D60 and 1Ds, its seems that CMOS have surpass CCD in terms of quality and noise level.

  4. #4

    Default Re: CMOS or CCD?

    Originally posted by JerChan
    What is the difference between a CMOS sensor, like those in the Canon D60 and the CCD sensor in the FujiFlim FinePix S2 Pro?

    I've seen photos taken with the FinePix S1 in print and they were crisp clear with vivid colors right down to the detail.

    Have yet to see a D30's or D60's photos in print.

    Any difference between CMOS and CCD? How would the difference be best described?

    Was told that CCD is better then CMOS. How true?
    The CMOS sensor used in cheap webcams, are different from the ones canon uses for their high end DSLRs. Yes, the underlying technology is the same but there is no fixed way to tell which is better.

    Some references, mostly older ones, say that cameras which uses CCD instead of CMOS sensors, but these are outdated. They don't take into account canon's recent work.

    But I doubt that CMOS is newer than CCD.

    Edit:
    CCD was orginally designed for capturing high quality images, CMOS wasn't. Thus, the disparity.

    A dated but quite good explanation from HSW:
    http://www.howstuffworks.com/digital-camera3.htm
    Last edited by Zoomer; 15th November 2002 at 03:27 PM.

  5. #5

    Default

    Originally posted by Shadus
    And of coz, CMOS is a much newer technology than CCD. Naturally, I'll expect it to take some time to develop.
    Having some bkg in microelectronics I'd say : NOT TRUE!! CMOS itself is very old tech

  6. #6

    Default

    Originally posted by nothing


    Having some bkg in microelectronics I'd say : NOT TRUE!! CMOS itself is very old tech
    I re-qual, CMOS as image capturing device is new technology.
    CMOS as an electronic device is really old.
    This is the reason why many people are quite excited about CMOS image sensors, cause they can be manufactured in any fabs of today. Instead of hving to build special fabs to manufacture CCD.

  7. #7
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    The Difference Between CCD and CMOS
    As prices continue to fall, more and more people are using digital cameras. The cameras are not as common as film cameras yet, but things are certainly moving in that direction. One of the drivers behind the falling prices has been the introduction of CMOS image sensors. CMOS sensors are much less expensive to manufacture than CCD sensors.

    A CMOS image sensor

    Both CCD and CMOS image sensors start at the same point -- they have to convert light into electrons at the photosites. If you've read the article How Solar Cells Work, you already understand one of the pieces of technology used to perform the conversion. A simplified way to think about the sensor used in a digital camera (or camcorder) is to think of it as having a 2-D array of thousands or millions of tiny solar cells, each of which transforms the light from one small portion of the image into electrons. Both CCD and CMOS devices perform this task using a variety of technologies.

    The next step is to read the value (accumulated charge) of each cell in the image. In a CCD device, the charge is actually transported across the chip and read at one corner of the array. An analog-to-digital converter turns each pixel's value into a digital value. In most CMOS devices, there are several transistors at each pixel which amplify and move the charge using more traditional wires. The CMOS approach is more flexible because each pixel can be read individually.

    CCDs use a special manufacturing process to create the ability to transport charge across the chip without distortion. This process leads to very high-quality sensors in terms of fidelity and light sensitivity. CMOS chips, on the other hand, use completely normal manufacturing processes to create the chip -- the same processes used to make most microprocessors. Because of the manufacturing differences, there are several noticeable differences between CCD and CMOS sensors.


    CCD sensors, as mentioned above, create high-quality, low-noise images. CMOS sensors, traditionally, are more susceptible to noise.
    Because each pixel on a CMOS sensor has several transistors located next to it, the light sensitivity of a CMOS chip is lower. Many of the photons hitting the chip hit the transistors instead of the photodiode.
    CMOS sensors traditionally consume little power. Implementing a sensor in CMOS yields a low-power sensor.
    CCDs, on the other hand, use a special process that consumes lots of power. CCDs consume as much as 100 times more power than an equivalent CMOS sensor.
    CMOS chips can be fabricated on just about any standard silicon production line, so they tend to be extremely inexpensive compared to CCD sensors.
    CCD sensors have been mass produced for a longer period of time, so they are more mature. They tend to have higher quality pixels, and more of them.
    Based on these differences, you can see that CCDs tend to be used in cameras that focus on high-quality images with lots of pixels and excellent light sensitivity. CMOS sensors usually have have lower quality, lower resolution and lower sensitivity. However, CMOS cameras are much less expensive and have great battery life. Over time, CMOS sensors will improve to the point where they reach near parity with CCD devices in most applications, but they are not there yet.


    Source

  8. #8

    Default

    Seems like article is a bit outdated.

    Anyway, high-end cams that uses CMOS

    -> D30, D60, 1Ds

  9. #9

    Default Re: CMOS or CCD?

    Originally posted by JerChan
    What is the difference between a CMOS sensor, like those in the Canon D60 and the CCD sensor in the FujiFlim FinePix S2 Pro?

    I've seen photos taken with the FinePix S1 in print and they were crisp clear with vivid colors right down to the detail.

    Have yet to see a D30's or D60's photos in print.

    Any difference between CMOS and CCD? How would the difference be best described?

    Was told that CCD is better then CMOS. How true?
    Does it matter ? What matters is the image at the end of the day. Get the camera that produces sharp saturated pictures at the price you can afford. It won't matter if it has a CCD or CMOS sensor.

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