Point & shoots, no improvement as long as sensors stay SMALL

Discussion in 'Digital Photography' started by Rich, Nov 5, 2007.

  1. Rich

    JosephKK Guest

    Ron Hunter posted to rec.photo.digital:
    In what universe is sensitivity and noise not interrelated?
    JosephKK, Nov 16, 2007
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  2. Since what limits burst length is the size of the buffer, then I'm
    surprised more don't offer a variable burst length dependent on
    selected image size. In effect video capability is a special case of
    that. It would sometimes be very handy to be able to run a very long
    burst at say a quarter of maximum resolution.
    Chris Malcolm, Nov 16, 2007
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  3. Rich

    John Navas Guest

    Fair enough, but there's a great difference between screen resolution
    (72-96 PPI) and good printing, where rules of thumb for normal viewing
    distances are at least 130 DPI for barely acceptable results, and up to
    230 DPI for excellent results. With current technology, anything more
    than 300 DPI is pretty much wasted. This translates to:

    4x6 5x7 8x10 11x14 16x20 20x30
    ------ ------ ------ ------ ------ ------
    Acceptable: 0.4MP 0.6MP 1.4MP 2.6MP 5 MP 10 MP
    Very good: 0.8MP 1.1MP 2.6MP 5 MP 10 MP 19 MP
    Excellent: 1.3MP 1.9MP 4 MP 8 MP 16 MP 32 MP
    Best: 2.2MP 3.2MP 7 MP 14 MP 28 MP 54 MP

    For my 7.2MP Panasonic FZ8, 11x14 is "excellent" at about 216 DPI.
    The same effect on my high-quality 96 PPI display is 96 / 216 = 44%
    zoom, more realistically 50% zoom. On a standard 72 PPI display it's
    72 / 216 = 33%.

    Even these reduced zooms exaggerate the issue, since display pixels are
    so much bigger and more distinct than high-resolution print dots. For
    this reason display zoom needs to be reduced even further for meaningful
    print judging, to about 25-33% (depending on display) for a high-quality
    (8MP) 11x14 print.

    Because screen pixels are so much larger and coarser than good printing
    dots (effectively a magnifier), zooming in more than this doesn't make
    sense (unless the ultimate objective is screen display of 100% crop
    rather than normal screen display or printing). If you can't see an
    issue at this reduced display zoom, then you're not going to see it in
    an excellent print either.

    Thus my normal practice is to assess images on screen at no more than
    33% zoom, zooming in farther only to examine the effectiveness of
    sharpening and/or noise reduction.

    This relationship does of course change for larger print sizes, but then
    print degradation due to pixelation becomes an offsetting issue -- more
    pixels are needed to make larger high-quality prints. When I anticipate
    printing larger than 11x14 with my 7.2MP Panasonic FZ8,
    I shoot multiple overlapping images and then stitch them together,
    multiple-frame super-resolution. 4 image stitching is sufficient for
    excellent 16x20 and very good 20x30 prints, and even larger sizes can be
    produced by stitching more images. In which case the same reduced zoom
    is appropriate.
    John Navas, Nov 16, 2007
  4. Rich

    John Navas Guest

    I guess so, because you're badly misinformed -- most DSLRs do have
    moving mirrors and mechanical shutters.
    John Navas, Nov 16, 2007
  5. Rich

    John Navas Guest

    Panasonic FZ-series bridge cameras can shoot burst mode at full
    resolution continuously until the memory card is full. In the case of
    the FZ8: 2 FPS continuous burst versus 3 FPS limited length burst.
    John Navas, Nov 16, 2007
  6. Rich

    John Navas Guest

    Depends on the camera. As I just posted, Panasonic FZ-series cameras
    have continuous burst mode at full resolution until the memory card is
    John Navas, Nov 16, 2007
  7. Rich

    Deep Reset Guest

    But you did remove the lens, didn't you?
    "misinformed" - sp. "deluded"
    Deep Reset, Nov 16, 2007
  8. Rich

    John Navas Guest

    In the real universe. You're confusing sensitivity from amplification
    (which increases noise) with basic sensitivity to light. Current Bayer
    sensors throw away about 80% of the incoming light, so there is huge
    room for sensitivity improvement without increasing noise. What Kodak
    is doing is trading color resolution for an increase of 2x to 4x in
    light sensitivity (1-2 stops), and since the human eye is much more
    sensitive to luminance than to chrominance, that may be a good tradeoff.
    Sample images are impressive, but how well it will work in real products
    in the real world remains to be seen. For more information see
    John Navas, Nov 16, 2007
  9. Rich

    Scott W Guest

    You really don't know what you are talking about, this is not a joke?

    Scott W, Nov 17, 2007
  10. Rich

    LaramieV Guest

    So do many Canon P&S cameras. The only limit to full-speed and continuous
    burst-shooting duration is the type of memory card installed. Too slow of a
    memory card and after the buffer fills up (about 30-50 shots later) it can have
    a slight lag between shots. Probably the same situation occurs in your P&S

    DSLRs on the other hand are limited to 10 to 30 frames before they slow down to
    half the rate that the better P&S cameras can do non-stop. It's odd that they
    would limit that to all resolutions in DSLRs. But there they sit, with a
    crippled burst-mode. Let me get in line to pay more for that!

    I don't depend on burst-modes often, only under special circumstances do I need
    it. When I do I'm glad it's there. People who have to rely on fast and long
    burst rates don't know much about photography. They're like the million monkeys
    at keyboards, eventually one of them might pound out something useful just by
    chance alone. You can always tell who doesn't know anything about photography
    when one of the few things that's better about a dSLR being it's short-lived but
    higher frame-rates becomes a main purchase point for them.

    If they only knew how much they were revealing about themselves with their
    camera feature priorities.
    LaramieV, Nov 17, 2007
  11. Rich

    John Navas Guest

    When photographing baseball games with my SLR, my high-speed motor drive
    lets me get great action shots (swinging at a pitch, diving catch) that
    I couldn't otherwise get. Likewise when photographing motor sports.
    Etc. Short high-speed burst is just what's needed, and the 5 frames per
    second is better than the 3 frames per second of my Panasonic FZ8. No
    one tool is perfect for all needs.
    John Navas, Nov 17, 2007
  12. Rich

    Ron Hunter Guest

    From the way my camera behaves in 'burst mode', it simply records the
    image to the buffer without doing the 'post processing' work normally
    done to process the image for storage. The raw data is stored in the
    buffer, and the normal things like sharpening, and compression, are done
    before writing the image to the card. This allows, in the case of my
    camera, about 6 images to be captured in 2.5 seconds. Then it takes a
    significant amount time to write all this to the card before I can
    resume normal operation. All this is conjecture from the way it seems
    to operate, but makes sense from a programming, and electronic point of

    As for variable burst length, sure, just release the shutter button!
    Ron Hunter, Nov 17, 2007
  13. From a review of one of the cheaper (i.e. lower end, i.e. slower) DSLRs:

    " "It does what it says on the box", and thankfully, too many camera
    manufacturer marketing departments are ready to over-inflate specs,
    Nikon however can be commended for delivering exactly the shooting rate
    quoted in their specs. The D40X achieved a consistent three frames per
    second, in JPEG mode it will shoot until the card is full (with a fast
    card), in RAW mode you're looking at between six and seven frames before
    slowing to 1.2 fps (no big concern as few people will shoot RAW


    Since in your words, that's half the rate that a good P&S can do,
    perhaps you'd care to name a specific "better P&S camera" that can shoot
    continuously at full resolution at 6 fps? Or, for that matter, a P&S
    that will get above 2.5 fps continuously in RAW mode?

    Daniel Silevitch, Nov 17, 2007
  14. Rich

    Guest Guest

    The older cameras, both digital & P&S were limited by the write speed to
    the memory card, but with faster cards this has gone away and the buffer
    can be flushed as fast as it can be filled, as long as you are using a
    high enough speed card. Amusingly, the manual for the last P&S I bought
    warned that the rated frame rate could not be achieved with the memory
    card they included.
    Guest, Nov 17, 2007
  15. Given the sorts of cards that are typically included, I'm surprised that
    the warning wasn't "with the included card, you can shoot for 3 seconds
    before the card is completely full". For a 32 meg card (typical, I
    think, for the included-in-the-box card), a 10 MP camera can save maybe
    8 full-resolution pictures.

    Daniel Silevitch, Nov 17, 2007
  16. Rich

    Guest Guest

    At maximum frame rate it _would_ have been about three seconds for the
    16MB card. Maybe that's why they include a slow card!

    Fortunately fast cards are very cheap. I picked up two SanDisk 2GB cards
    for $25 each. Micro-Center was giving away 2GB slow cards with a coupon,
    which are fine for storage for digital picture frames, or for the SD
    slot present on many notebooks these days.
    Guest, Nov 17, 2007
  17. Rich

    Rich Guest

    And hence we have a new class system in cameras that didn't exist
    before. In the 1980s, someone with a Pentax K1000 could theoretically
    take as good a picture of something as a Nikon F3, but now, there is
    no way in Hell someone with a 1/2.5" sensor-equipped P&S can begin to
    match what a FF, 1.5 or even a 4/3rds DSLR can deliver.
    Rich, Nov 17, 2007
  18. Rich

    Rich Guest

    It's the "silk purse from the sow's ear" theory that you can make,
    using technology, something decent out of something that wasn't to
    begin with (the output of a small sensor) and we know it just isn't
    Rich, Nov 17, 2007
  19. Rich

    Ron Hunter Guest

    Yes, and the same goes for 'movie mode'. I have one card that is so
    slow that when I try to use it in movie mode, I get skipped frames. Not
    a problem for general picture-taking but it makes a difference when
    snapping as fast as possible, or doing something like burst mode.
    The system is only as fast as the slowest involved part.
    Ron Hunter, Nov 17, 2007
  20. Rich

    Ron Hunter Guest

    That depends entirely on WHO is taking the picture, and when, and where.
    In good light, it really matters very little. In bad conditions, the
    DSLR will certainly help. Of course the photographer may have set the
    wrong aperture, wrong shutter speed, and fouled up the focus, too.
    Makes for a lousy picture.
    Ron Hunter, Nov 17, 2007
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