CCD vs CMOS in sensor technology?

Discussion in 'This or That? (MFT only)' started by gdourado, Jun 7, 2012.

  1. gdourado

    gdourado Mu-43 Regular

    117
    Feb 23, 2012
    Lisbon - Portugal
    CCD vs CMOS vs Foveon in sensor technology?

    Hello,

    How are you?
    Because I am into photography, I spend some time reading stuff, either in books, or online forums, or blogs... You name it...
    So today I came across some reading regarding sensor technology, namely, the CCD vs CMOS techs...
    From what I read, Canon always used CMOS sensors on their DSLRs, from the old EOS D60 to the new 5D mark III...
    On the other hand, I read than Nikon used CCD sensors on some of their older cameras, like the D70, the D80, the D2X, D100, D200...
    I read that these old sensors if you count out resolution and high ISO performance, perform better than the CMOS sensors on modern Nikons, like the D300, D7000, D90...
    So, since I am far from a tech expert... I decided to post this here, to hear from you, what are your experiences and opinions on this matter, as well as technical knowledge...

    Some say that in the Digital Age, sensor tech is not that important because you can post process all your photos and achieve the look you want...
    But I also hear from people who, for example, shoot Sigmas with their Foveon sensors, and they swear by them in color reproduction and detail... So, what's your take?

    Thank you.
    Cheers!
     
  2. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    Practically, there is no difference. Since every image goes through signal processing and every manufacturer manages their own color, the sensor type make less of a difference. I doubt you could spot a difference in any image made by both sensor types. I use cameras with both CCDs and CMOSs. But Foveon sensors are different and you can see it in the images.
     
  3. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    When CMOS first came out, it was a mass-production product which greatly reduced cost of manufacture as well as power draw of the old CCD technology. People took the hit in image quality for cheaper manufacture and low power consumption.

    This is no longer the case, as CCD technology hit a stand-still while CMOS technology moved forward due to its more practical nature. Our CMOS sensors of today can greatly out-resolve the old CCD sensors of old, so the inherent image quality gain of the old CCD technology is now moot.

    Olympus and Panasonic Four-Thirds sensors do not use CCD or CMOS... and have in fact never used CMOS. The original Four-Thirds sensors were CCD then they were switched over to NMOS, which is supposed to give you the higher image quality of a CCD along with the lower power consumption of the CMOS. The best of both worlds supposedly, though in reality it was more of an "in-between". I don't think the early NMOS sensors ever produced the same quality as the late CCD sensors.

    However, CMOS and NMOS have been around long enough now that CCD holds no more advantage. It's just like Compact Flash (CF) cards and Secure Digital (SD). SD was the cheap way, but were not as fast, reliable, or high-capacity as CF. So SD cards started gaining in consumer cameras (ie, point-and-shoots), while CF remained the standard for any professional digital photography from DSLR to Medium Format. Now you see SD used in all kinds of camera types, but they are now far more robust, fast, and high-capacity. With the SDHC (SD High Capacity, 4GB - 32GB) and SDXC (SD Xtra-High Capacity - 64GB+) formats, we now have even greater capacity in SD than we did in CF. Where SD cards used to fail and fall apart easily, they are now built really durable (especially cards like Sandisk) and reliable.

    We may see this same progression with Non-Reflex cameras soon. DSLRs were the de facto format for many for so long. They hold a few inherent advantages, but SLR technology has now now been around for over 60 years and has come to a standstill. Non-Reflex technology is overall a more "practical" system with a great reduction in size and cost, and we are seeing this technology grow by leaps and bounds in a race to catch up and surpass existing DSLRs. People are continuing to invest more and more in non-reflex technology, and we are seeing the same drastic shifts in use of formats as we had seen with CCD vs CMOS and CF vs SD.

    Years from now, people will be starting threads saying, "I read on the internet that there used to be this camera format called DSLR which was even better for sports than the cameras we use now".

    PS, I will admit that I was once one of those who resisted these changes. I didn't like the switch from CCD to the lower-quality CMOS or NMOS sensors. I also wanted to hold onto my CF cards and hated when companies started replacing their CF slots with SD. Until the first Olympus Digital PEN came out, then I saw that there was no way around using the smaller SD format. I eventually became relieved that I was finally able to use much cheaper, smaller cards which also had no problems with bending pins - and one which was embraced by consumer electronics, allowing me to have built-in SD readers in my laptop, digital picture frames, etc. and SD card readers sold everywhere. CF always required hard-to-find card readers because although professional photographers embraced the format, computer manufacturers did not (Remember Firewire vs USB? Same thing - all professional videographers used firewire, yet computer manufacturers never made that technology easily available. Even I use USB now, because I could only outfit my desktop with firewire and not my laptop - but desktops are now passé).

    I am now much more open to embracing these changes, and pioneering new formats which show better potential for the future. There will always be inherent strengths that we leave behind in the old formats, but the overall change for the better helps us to move forward to bigger things.
     
  4. lenshoarder

    lenshoarder Mu-43 All-Pro

    Nov 7, 2010
    Here's a bit of trivia. A CMOS sensor is basically just a RAM chip. Back in the olden days, we used to lift the lid off of RAM chips to use as camera sensors. This is back when chip housing were made out of ceramic with a metal lid on top.
     
  5. Aegon

    Aegon Mu-43 Veteran

    334
    Nov 3, 2011
    Portland, OR
    CCD sensors take the signal from the photosites and send the signals down the line to the edge of the chip where amplifiers bump the signal strength for entire rows of data. This leads to a few tradeoffs, including the following:

    Separating the amps from the photosites allowed photosite design to take maximum advantage of the given real estate, therefore CCD photosites can sometimes be physically larger on the surface as well as in the substrate. In contrast, CMOS amps are generally built-in to the substrate beneath the photosites, sometimes leading to cramped photosites. Additionally, each amplifier may have slightly different characteristics due to manufacturing tolerances so that the differences appear as a baseline noise characteristic which is visibly worse than the shared amps from CCDs.

    CCD amps are bigger and need more power, and their signals have to be higher voltage. CMOS amps are distributed through the sensor, and tend to dissipate heat into the substrate such that noise can be introduced as a side effect of the heat.

    On the other hand, the proximity of CMOS amps to the photosites provides for greater sensitivity and faster response times. The image can be pulled from each photosite approximately simultaneously to allow for video and live view.

    I personally prefer the look of CCD, but I definitely prefer the high-ISO improvements of CMOS. I keep a K10D because at ISO 100 it looks amazing. I keep a K-5 because at ISO 6400 it looks amazing (for the conditions). Other than that, most people won't choose one technology over the other, but rather take the technology that is implemented in the camera of their choice.

    I'd also like to clarify that you'd have to be some sort of connoisseur to tell a modern CMOS apart from CCD at ISO 100. I think CCD looks great at base ISO, but CMOS also looks great.
     
  6. WT21

    WT21 Mu-43 Hall of Famer

    Feb 19, 2010
    Boston
    Aegon and Ned pretty much said it all.

    From a practical point of view: I have shots from my Canon compact 1/1.8" SD800 at ISO80 where the skies are really blue, and there is little visible noise. Something I can't really get in the 43 and even APS-C CMOS sensors today. But the SD800 maxed out at 640X480 video (Canon did get a TX1 I think it was called, to do 720 with a CCD) and high ISO was poor. "High ISO" being 400 and up!
     
  7. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Which is very similar to what people love about the old Olympus E-1 with the 5MP Kodak CCD sensor. The signature blues especially in the skies are what most distinguish the E-1. But just as with your compact, ISO 400 is high. lol.
     
  8. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    The only advantage to CMOS is live view. As far as a difference in image quality between CMOS and CCD, I have never been able to see it, which is not surprising as they both have color blind pixels and the same Bayer filters--I shoot medium-format digital and scientific cameras which have CCDs.
     
  9. kinlau

    kinlau Mu-43 Top Veteran

    836
    Feb 29, 2012
    I kept my old Canon 1D classic 4mp for a while because of one advantage the CCD sensor gave, that it could flash sync at 1/500 or even higher with strobes or just about any flash. The old Nikon D70 had the same feature.
     
  10. RobWatson

    RobWatson Mu-43 Hall of Famer

    What's better live performance, vinyl, 8 tracks, cassettes, reel to reel, CD's, MP3 ... tech marches on. Depends on what you want to do - nice to have choices. Same goes for eyeballs, paintings, film, CCD, EBCCD, CMOS, NMOS, sCMOS, InGaAs, etc.

    CCDs started out as memory chips ... Viagra started out as blood pressure meds.

    Sometimes I even remember to take of the lens cap.
     
  11. gdourado

    gdourado Mu-43 Regular

    117
    Feb 23, 2012
    Lisbon - Portugal
    Hi...

    So, today I saw on a store a kit with a Sigma SD15 with the 18-50 2.8-4.5 lens for one very good price.
    It is a 2010 camera, but it has a unique sensor, a Foveon.
    Form what I read, it is suposed to deliver excellent color thanks to it's 3 layers and excellent sharpness because it does not have a low pass filter.

    Any experience with this sensor? Is it really that good?

    Cheers!
     
  12. kinlau

    kinlau Mu-43 Top Veteran

    836
    Feb 29, 2012
    The Foveon has a different color response, but the real bonus is the removeable hot-mirror. Instant IR camera.
     
  13. gdourado

    gdourado Mu-43 Regular

    117
    Feb 23, 2012
    Lisbon - Portugal
    And the part of the different color response? Is it that much different or just slightly?
    Is it a technology worth exploring? Or just a gimmick?

    Cheers!
     
  14. kinlau

    kinlau Mu-43 Top Veteran

    836
    Feb 29, 2012
    I don't have one myself, but by having each photo site capture all three colors, you should get a truer/better color capture than the guess work that goes into Bayer-types. The problem with the Sigma, is that it's quite slow by dslr standards. Still not bad for a new 'toy'.
     
  15. OldSchool

    OldSchool New to Mu-43

    8
    Aug 5, 2012
    I think Ned pretty much covered the essence of the debate. I have invested in a company that pioneered one CMOS technology and have been following the the image sensor development for years. CMOS sensor is on its way to overtake the image sensor market starting from the mass market of the cell phones and now invading the digital still and video market. The new BSI (Back Side Imaging) technology of CMOS image sensor pioneered by Omnivision Technology was adopted by iPhone 4 due to its superior quality (efficiency, low light sensitivity, dynamic range, etc.). Now Sony and Samsang all have caught up and are supplying this new type of CMOS sensors. When a Sony 8MP BSI CMOS was found inside of an iPhone 4S, the news caused quite a splash. Many of you might be aware that some of the new cameras introduced this year use the new 16MP CMOS sensors that are of this type.

    The battle between the CCD and CMOS is essentially over, after two of the largest chip makers/image sensor producers joined the bandwagon in full force.
     
  16. jnewell

    jnewell Mu-43 All-Pro

    Jun 23, 2011
    Boston, MA
    I agree that the debate is essentially over. The market has ended it for all practical purposes.

    I thought a fair bit about this, and did a lot of image review, when I sold my D200. The differences in sensor results weren't that great, and the sensor was becoming somewhat limited by the body in which it was captive.
     
  17. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    Over for whom? I still use medium-format and scientific cameras that have CCDs. There is no way I can replace the sensor in them and there is no point in buying a different camera.
     
  18. jnewell

    jnewell Mu-43 All-Pro

    Jun 23, 2011
    Boston, MA
    Over from the perspective of new cameras available for sale - I should have been clearer.

    And yes, I agree about "outdated" cameras still taking great pictures. My M8 did not suddenly start making bad files when the M9 was introduced, nor my GF1 when the GX1 was introduced, nor my D200 when the D300 was introduced...but there are sometimes other reasons to replace a camera (e.g., improved AF or high speed operation).
     
  19. OldSchool

    OldSchool New to Mu-43

    8
    Aug 5, 2012
    "Over" from the perspective of sensor technology development, not from camera user's in a short term. I am also using scientific cameras that have CCD and CMOS sensors and cost more than $50,000. But I have seen where the image sensor developers are putting their money these days. A few players failed to see the "light" soon enough and was left behind. Kodak happened to be one of them.