Re: Sigma

Discussion in 'Digital Photography' started by Mike Graham, Sep 13, 2003.

  1. Mike Graham

    Mike Graham Guest

    In article <-b.net>, David Dyer-Bennet wrote:

    > And the no anti-aliasing filter issue.


    I hadn't heard about this. It suffers from 'the jaggies' does it?

    > And, it turns out that Bayer pattern filters work much better than a
    > simplistic analysis would give you any reason to expect.


    I haven't noticed any problems with them, so they certainly *must*. When
    compared on a similar-number-of-detectors basis, the bayer seems to win in
    details, but in a similar-number-of-pixels basis the foveon beats it badly.
    That's where the info seems to lead me at the moment.

    --
    =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Mike Graham | Metalworker, rustic, part-time zealot.
    mike 'at' metalmangler.com |
    <http://www.metalmangler.com>| Caledon, Ontario, Canada

    Lousy photographer with a really nice camera - Olympus C3020Zoom.
    <http://www.metalmangler.com/photos/photos.htm>
    <http://www.photo.net/shared/community-member?user_id=766040>
     
    Mike Graham, Sep 13, 2003
    #1
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  2. Mike Graham <> writes:

    > The current thread about CCD structure got me thinking about that foveon
    > detector. If a foveon chip is a 2MP chip, then it actually has 6 million
    > detectors, because it has three detectors for each pixel. Correct? So the
    > 3.4 or whatever number of megapixels that the Sigma SD-9 outputs, would
    > equate to somewhere around 11MP of detectors. I wonder how it would stack
    > up against an 11MP bayer chip?
    > I suppose the real drawbacks are the sigma lens mount and the no-jpeg
    > issue.


    And the no anti-aliasing filter issue.

    And, it turns out that Bayer pattern filters work much better than a
    simplistic analysis would give you any reason to expect.
    --
    David Dyer-Bennet, <>, <www.dd-b.net/dd-b/>
    RKBA: <noguns-nomoney.com> <www.dd-b.net/carry/>
    Photos: <dd-b.lighthunters.net> Snapshots: <www.dd-b.net/dd-b/SnapshotAlbum/>
    Dragaera mailing lists: <dragaera.info/>
     
    David Dyer-Bennet, Sep 14, 2003
    #2
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  3. Mike Graham <> writes:

    > In article <-b.net>, David Dyer-Bennet wrote:
    >
    > > And the no anti-aliasing filter issue.

    >
    > I hadn't heard about this. It suffers from 'the jaggies' does it?


    Aliasing on fine detail, and some additional moire opportunities
    mostly.

    > > And, it turns out that Bayer pattern filters work much better than a
    > > simplistic analysis would give you any reason to expect.

    >
    > I haven't noticed any problems with them, so they certainly *must*. When
    > compared on a similar-number-of-detectors basis, the bayer seems to win in
    > details, but in a similar-number-of-pixels basis the foveon beats it badly.
    > That's where the info seems to lead me at the moment.


    The basis to actually compare on, it seems to me, is
    similar-number-of-dollars; since the decision involved is how to spend
    your photo equipment money. What you need to know is what kind of
    results you can get for it with various choices.
    --
    David Dyer-Bennet, <>, <www.dd-b.net/dd-b/>
    RKBA: <noguns-nomoney.com> <www.dd-b.net/carry/>
    Photos: <dd-b.lighthunters.net> Snapshots: <www.dd-b.net/dd-b/SnapshotAlbum/>
    Dragaera mailing lists: <dragaera.info/>
     
    David Dyer-Bennet, Sep 15, 2003
    #3
  4. Mike Graham

    Mike Graham Guest

    In article <-b.net>, David Dyer-Bennet wrote:

    > Aliasing on fine detail, and some additional moire opportunities
    > mostly.


    In the photos I had seen there was far less moire patterning than there
    was with a D100, 10D, etc.

    > The basis to actually compare on, it seems to me, is
    > similar-number-of-dollars; since the decision involved is how to spend
    > your photo equipment money. What you need to know is what kind of
    > results you can get for it with various choices.


    Well, the Sigma is cheaper than a 10D up here. Actually, you can get a
    Sigma with 2 lenses for cheaper than a 10D, IIRC.

    --
    =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Mike Graham | Metalworker, rustic, part-time zealot.
    mike 'at' metalmangler.com |
    <http://www.metalmangler.com>| Caledon, Ontario, Canada

    Lousy photographer with a really nice camera - Olympus C3020Zoom.
    <http://www.metalmangler.com/photos/photos.htm>
    <http://www.photo.net/shared/community-member?user_id=766040>
     
    Mike Graham, Sep 15, 2003
    #4
  5. Mike Graham <> writes:

    > In article <-b.net>, David Dyer-Bennet wrote:
    >
    > > Aliasing on fine detail, and some additional moire opportunities
    > > mostly.

    >
    > In the photos I had seen there was far less moire patterning than there
    > was with a D100, 10D, etc.


    I suspect you have to compare photos from similar locations to
    actually get a meaningful result.

    > > The basis to actually compare on, it seems to me, is
    > > similar-number-of-dollars; since the decision involved is how to spend
    > > your photo equipment money. What you need to know is what kind of
    > > results you can get for it with various choices.

    >
    > Well, the Sigma is cheaper than a 10D up here. Actually, you can get a
    > Sigma with 2 lenses for cheaper than a 10D, IIRC.


    I agree that the cost factor works somewhat *for* the Sigma; I'm not
    single-mindedly working to trash it here by any means.
    --
    David Dyer-Bennet, <>, <www.dd-b.net/dd-b/>
    RKBA: <noguns-nomoney.com> <www.dd-b.net/carry/>
    Photos: <dd-b.lighthunters.net> Snapshots: <www.dd-b.net/dd-b/SnapshotAlbum/>
    Dragaera mailing lists: <dragaera.info/>
     
    David Dyer-Bennet, Sep 16, 2003
    #5
  6. Mike Graham

    Mike Graham Guest

    In article <-b.net>, David Dyer-Bennet wrote:

    > I suspect you have to compare photos from similar locations to
    > actually get a meaningful result.


    These were photos of a resolution chart on dpreviews. Let me see if I can
    find the URL... here it is:
    <http://www.dpreview.com/reviews/sigmasd9/page23.asp>

    Check this out. To my eye it looks like the foveon chip had virtually
    zero moire issues, but the three bayer chip cameras it was compared to
    (Nikon D100, Canon D60, and Fuji S2 Pro) all showed significant amounts in
    the patterns of tight lines.

    --
    =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Mike Graham | Metalworker, rustic, part-time zealot.
    mike 'at' metalmangler.com |
    <http://www.metalmangler.com>| Caledon, Ontario, Canada

    Lousy photographer with a really nice camera - Olympus C3020Zoom.
    <http://www.metalmangler.com/photos/photos.htm>
    <http://www.photo.net/shared/community-member?user_id=766040>
     
    Mike Graham, Sep 16, 2003
    #6
  7. Mike Graham

    Alan F Cross Guest

    In message <>, Mike Graham
    <> writes
    >In article <-b.net>, David Dyer-Bennet wrote:
    >
    >> I suspect you have to compare photos from similar locations to
    >> actually get a meaningful result.

    >
    > These were photos of a resolution chart on dpreviews. Let me see if I can
    >find the URL... here it is:
    ><http://www.dpreview.com/reviews/sigmasd9/page23.asp>
    >
    > Check this out. To my eye it looks like the foveon chip had virtually
    >zero moire issues, but the three bayer chip cameras it was compared to
    >(Nikon D100, Canon D60, and Fuji S2 Pro) all showed significant amounts in
    >the patterns of tight lines.
    >


    My understanding is that the Sigma looks cleaner, without moire, because
    it has no AA filter. But it is all an illusion, because you have to look
    at the pattern of lines and compare it with the original chart. The
    lines are sharp, but they are not the same lines (or necessarily the
    same number of lines) as the original chart.
    --
    Alan F Cross
     
    Alan F Cross, Sep 22, 2003
    #7
  8. Mike Graham

    Mike Graham Guest

    In article <e+$IY0IxD3b$>, Alan F Cross wrote:

    > My understanding is that the Sigma looks cleaner, without moire, because
    > it has no AA filter. But it is all an illusion, because you have to look
    > at the pattern of lines and compare it with the original chart. The
    > lines are sharp, but they are not the same lines (or necessarily the
    > same number of lines) as the original chart.


    Are you suggesting that a foveon chip would be more prone to optical
    illusions? That is, that an un-interpolated image would be more prone to
    optical illusions than an interpolated one?

    --
    =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Mike Graham | Metalworker, rustic, part-time zealot.
    mike 'at' metalmangler.com |
    <http://www.metalmangler.com>| Caledon, Ontario, Canada

    Lousy photographer with a really nice camera - Olympus C3020Zoom.
    <http://www.metalmangler.com/photos/photos.htm>
    <http://www.photo.net/shared/community-member?user_id=766040>
     
    Mike Graham, Sep 24, 2003
    #8
  9. "Mike Graham" <> wrote in message
    news:...
    SNIP
    > Are you suggesting that a foveon chip would be more prone to optical
    > illusions? That is, that an un-interpolated image would be more prone to
    > optical illusions than an interpolated one?


    Yes, without an AA-filter it would.

    Bart
     
    Bart van der Wolf, Sep 24, 2003
    #9
  10. Mike Graham

    Mike Graham Guest

    In article <3f721949$0$58698$4all.nl>, Bart van der Wolf wrote:

    >> Are you suggesting that a foveon chip would be more prone to optical
    >> illusions? That is, that an un-interpolated image would be more prone to
    >> optical illusions than an interpolated one?

    >
    > Yes, without an AA-filter it would.


    I guess we'll just have to agree to disagree on that, then.

    --
    =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Mike Graham | Metalworker, rustic, part-time zealot.
    mike 'at' metalmangler.com |
    <http://www.metalmangler.com>| Caledon, Ontario, Canada

    Lousy photographer with a really nice camera - Olympus C3020Zoom.
    <http://www.metalmangler.com/photos/photos.htm>
    <http://www.photo.net/shared/community-member?user_id=766040>
     
    Mike Graham, Sep 24, 2003
    #10
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