Bayer with NO anti-aliasing (Kodak Pro 14n)

Discussion in 'Digital Photography' started by K2, Nov 28, 2003.

  1. Yeah, I know. But I am just curious if George means spatial in the
    third dimension, i.e. depth when he says that the SD9 has 10 million
    spatial samples.


    Roland
     
    Roland Karlsson, Dec 5, 2003
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  2. How irritating. You say exactly what I say and make
    it look like you argue with me. Are you just making
    fun of us, or what is your problem?


    Roland
     
    Roland Karlsson, Dec 5, 2003
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  3. Not really. What is new is that they made a camera. There
    are already devices that uses the wavelength dependent
    absorbtion, i.e. color sensors. I have read the Foveon patent,
    and really it is (like many patents) questionable. The
    ideas were already known, but no one dared to invest money
    to make it a reality. It was generally thought as not a good
    idea. Foveon has shown that it is possible and might even
    become a very good idea, when done right. Good work.


    Roland
     
    Roland Karlsson, Dec 5, 2003
  4. Foveon doesn't sample for color, it captures only full colors, that is the
    difference.
     
    George Preddy, Dec 5, 2003
  5. Ask John, he's the one that says even though Foveon images look better they
    aren't.
     
    George Preddy, Dec 5, 2003
  6. You said "only an idiot" would compare the optical resolution of a 1Ds to an
    SD9 with different FOVs. That is the only way to compare optical
    resolution.

    Cropping is not optical zoom. The SD9 crops a picture from a 35mm lens
    projection, the 1DS doesn't, that is what generates the FOV difference.

    The reviewer, wasn't an idiot.
     
    George Preddy, Dec 5, 2003
  7. George - where did I mention Bayer? Nope! So - what difference are
    we talking about? Any sampling system needs anti alias filters in
    order to avoid aliasing.


    Roland
     
    Roland Karlsson, Dec 5, 2003
  8. K2

    JPS Guest

    In message <bqqqle$f87$>,
    No, you pathetic liar; I didn't say anything like that.

    I said they look sharp with sharp lenses, but the sharpness is not
    legitimate detail. The sharpness is due to the fact that the Foveon
    sensors are sampling an area much smaller than their jurisdiction, when
    in fact, they should be sampling an area about 4x their jurisdiction.
    The results are similar to sampling properly at something like 56mp, and
    using Nearest Neighbor to downsize to 3.43mp.

    Don't paraphrase what you don't understand.
    --
     
    JPS, Dec 6, 2003
  9. No, I didn't. I said comparing a different field of view would be only done
    by an idiot.

    Bart
     
    Bart van der Wolf, Dec 6, 2003
  10. It's even pretty hard to call them independent measurements. The sensor
    response overlap so much that the green and blue sensors recieve about the
    same amount energy even if you are only shining a green light on them. They
    are highly correlated.
     
    Gherry Bender, Dec 6, 2003
  11. That's also true of antialiasing filters, at least the ones that work
    by presenting a double image one pixel apart to the sensor. The
    frequency response of the filter alone is cos(pi*x) where "x" is in
    cycles/pixel, so it has a zero at x=0.5 and other ones at 1.5, 2.5 etc.
    But it doesn't attenuate information at 1, 2, 3... cycles/pixel.

    So the complete system must depend on the AA filter to provide the
    sharp cutoff near 0.5 cycles/pixel, while the area of the pixels
    (or microlenses) attenuates around 1 cycles/pixel, and the ultimate
    attenuation of higher frequencies is provided by the lens which probably
    has a roughly Gaussian frequency response.

    Dave
     
    Dave Martindale, Dec 6, 2003
  12. An idiotic fraud? A fraudulent idiot?

    I see: Bart and I are both right.

    Dave
     
    Dave Martindale, Dec 6, 2003
  13. Doesn't one of the Nikon cameras do just that?

    There's also the hexagonal grid, with the same pattern as the early
    triad-gun colour TV sets. Exactly 1/3 of all locations are each red,
    green, and blue, all evenly spaced. In some sense, this is the ideal
    sensor pattern for both B&W and Bayer-type colour cameras, if you ignore
    the difficulty in fabricating the sensor (I'll bet it's a lot easier to
    lay out CCD gates in a row/column arrangement than a hexagonal grid)
    and processing the data to convert to the standard grid.

    Dave
     
    Dave Martindale, Dec 6, 2003
  14. You are simply wrong. FOV-cropping is not optical magnification, its
    cropping. That is why it is called, guess what? The "crop factor." This
    is why the Canon 1Ds has such poor optical resolution compared to the SD9,
    the SD9 has the roughly same sensor count packed into a smaller sensor area.
    The 1Ds has a wider FOV, but dramatically lower optical resolution...
    http://www.outbackphoto.com/artofraw/raw_05/essay.html
     
    George Preddy, Dec 6, 2003
  15. That aliases a tiny little bit in some small areas of approx 1 in 3000
    shots, as measured by objective third party pro reviewers.
     
    George Preddy, Dec 6, 2003
  16. See above:
    I never mentioned cropping, you do.
    I never mentioned optical magnification, you do.

    An obvious lack of reading skills.

    Bart
     
    Bart van der Wolf, Dec 6, 2003
  17. K2

    JPS Guest

    In message <bqsmkk$48j$>,
    f45? Dirty filter?

    *ALL* sharp SD9 images are completely filled with aliasing, in the
    area(s) of focus.
    --
     
    JPS, Dec 6, 2003
  18. Absolutely, RGB samples come from mutually exclusive populations. To build
    an image, you have a sseparate R channel, a G channel, and a B channel, it
    doesn't matter if a sensor is co-located unless it is in the same color
    channel, which its not. Foveon takes 10.3M spatially discrete samples,
    Bayer 6MP-interpolated only has 6M.
     
    George Preddy, Dec 6, 2003
  19. Unless they sample from mutually exclusive populations.
     
    George Preddy, Dec 6, 2003
  20. Correct, and it doesn't make a bit of difference if you layer the 3 color
    sensors perfectly aligned, or you slide each of them 1 pixel sideways using
    a mosiac then color interpolate, they don't sample the same populations so
    the photosites in each channel are just as discrete either way.
     
    George Preddy, Dec 6, 2003
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