Fuji F5 has a 14 bit A to D

Discussion in 'Fuji' started by RichA, Dec 7, 2006.

  1. RichA

    RichA Guest

    So now Pentax, Leica and Fuji have gone beyond 12 bit. Can Nikon and
    Canon be far behind.
    Body material Magnesium alloy
    Sensor · Fujifilm SuperCCD SR II
    · 23.0 x 15.5 mm
    · 2 photodiodes per photosite (one S and one R)
    · RGB color filter array
    · 14 bit A/D converter
    RichA, Dec 7, 2006
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  2. don't forget Minolta in the consumer level A1 5 megapixel camera - 14
    bit. And Kodak of course in the DCS Pro final models.

    David Kilpatrick, Dec 7, 2006
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  3. RichA

    RichA Guest

    Some people have stated that going beyond 12-bit in a consumer camera
    (DSLR or P&S) doesn't make any visible difference, but it must have
    some value because I assume it does cost a bit more to go with the
    higher quality ADCs.
    RichA, Dec 7, 2006
  4. RichA

    Bill Guest

    Yes, likely marketing value = ours is bigger than yours.
    Bill, Dec 8, 2006
  5. RichA

    Wm. Harris Guest

    Don't reply to this asshole.
    Wm. Harris, Dec 8, 2006
  6. Some people said the same with slide scanners, but every 12-bit slide
    scanner I have used has been inadequate for almost every job.

    Can you still buy 12-bit slide scanners?
    Kennedy McEwen, Dec 8, 2006
  7. RichA

    Scott W Guest

    There is some pretty good evidence that in many DSLRs the 12 bit
    converters are the limiting factor in the dynamic range of the camera.
    Whereas 12 bit of range is not a limit that is hard to live with it
    does seem to make sense to add a couple of bits and get the full range
    that the sensor is capable of.

    Scott W, Dec 8, 2006
  8. Your opinion of David is not shared by this poster - I value his
    contributions and find a lot of interest in what he has to say.
    David J Taylor, Dec 8, 2006
  9. That would take a few more than just "a couple of bits". With, say, a
    typical storage capacity of 500,000 electrons and a read noise of less
    than 5, we need at least 17-bits to "get the full range that the sensor
    is capable of" - and some cameras have more capacity and lower read

    14-bits is certainly better than 12, but it will still be "the limiting
    factor in the dynamic range of the camera".
    Kennedy McEwen, Dec 8, 2006
  10. As do I.

    I wasn't going to respond at all until the other David did.

    The big question is: Who the hell is Harris?
    John McWilliams, Dec 8, 2006
  11. I thought the typical DSLR was in the region of 50,000 - 100,000 electrons
    well capacity?

    David J Taylor, Dec 8, 2006
  12. RichA

    acl Guest

    But which sensor doesn't overflow with 500,000 electrons?
    acl, Dec 8, 2006
  13. RichA

    Scott W Guest

    They are much closer in that range, 50,000 to 100,000.

    And easy test to see how many more bits are useful is to set the camera
    in manual mode and shot a scene at increasing ISO setting. You need to
    have the exposure set so that at the highest ISO you are not over
    exposing. Asjust all the photos to look the same and look at the
    detail captured in the shadows. For my 20D I get pretty big
    improvments going from ISO 100 to 200 and more yet going from 200 to
    400 but the gain is pretty small going from 400 to 800. Note when
    doing this test you need to shoot raw and output as 16 bit /color tiff
    files, otherwise you aren't getting the full use of the 12 bits

    Scott W, Dec 8, 2006
  14. I got that number from a couple of DALSA CCD data sheets, some are
    certainly lower than that.
    Kennedy McEwen, Dec 8, 2006

  15. For one, the DALSA FTF-3020, which happened to be the first I looked at
    since I was considering it myself some time back, but take a look at
    others in the range, they aren't that much different.

    Then again there are the Fuji devices that are designed specifically so
    that some sensels don't saturate as low as others. All of which just
    makes the problem even more difficult for the ADC which rarely have
    noise floors down at the quantisation limit of themselves.
    Kennedy McEwen, Dec 8, 2006
  16. RichA

    acl Guest

    But how did you get 500,000 electrons for that? As in, how do you
    calculate it with their numbers?

    Also, they only claim a linear dynamic range of around 14000 (which is
    much less than 500,000/5).

    Or did you mean something else?
    acl, Dec 8, 2006
  17. RichA

    acl Guest

    Never mind, I missed the page where they give the electron/voltage
    conversion factor. You're right, it's around 400-500,000.
    acl, Dec 8, 2006
  18. RichA

    acl Guest

    Looking at the datasheet for the FTF-3020 that KM mentioned, if you take
    the full-well capacity for linear operation (2100 mV) and 8.5
    microvolts/electron (this is what they quote) you get 250,000 electrons.
    The pixel size of this thing is 12x12 microns, so for a camera with a
    pixel size of eg 8x8 microns and everything else equivalent, we'd get
    around 100,000, which is what everybody would expect.
    acl, Dec 8, 2006
  19. RichA

    Scott W Guest

    I believe Harris was refering to Rich and not David, telling David not
    to respond to Rich, not for the rest of us not to respond to David.

    I don't mind Rich as long as it is not another post about plastic.

    Scott W, Dec 8, 2006
  20. RichA

    Paul Furman Guest

    Ha, that's not a standard sort of camera, b&w at 18fps.

    DALSA's FTF3020 was the first 6 megapixel 35 mm sensor, and its
    remarkable image quality made it the de facto standard for digital still
    photography. It still provides the highest possible image quality for
    its resolution, with lower dark current, lower noise, and higher dynamic
    range than any competitor...
    Pixel Size: 12µm x 12µm
    Active Area: 36.9mm x 24.6mm
    Dynamic Range: >72 dB linear

    full well Gain Read Pixel
    Camera (electrons) Electrons/ Noise Spacing Sensor size
    ISO 100 DN ISO100 electrons (microns) pixels mm
    Canon 1DMII 52,300* 13.02 16.6 8.2 3504 x 2336
    28.7 x 19.1
    Canon 10D 44,200 11.4 16 7.4 3072 x 2048
    22.7 x 15.1
    Canon S60 11,000* 2.7 14 2.8 2592 x 1944
    7.18 x 5.32
    Canon S70 4,300* 1.03 4.1 2.3 3072 x 2304
    7.18 x 5.32

    *The Canon 1D Mark II has a true full well of 79,900 electrons at ISO 50.
    *The Canon S60 has a true full well of ~22,000 electrons at ISO 50.
    *The Canon S70 has a true full well of 8,200 electrons at ISO 50.
    Paul Furman, Dec 8, 2006
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