Higher pixel count does not mean better resolution!

Discussion in 'Digital Photography' started by JohnR, Oct 17, 2004.

  1. JohnR

    JohnR Guest

    Wile looking for a replacement for my Fuji 3MP camera for one with more
    manual control, I got to compare it to the 4mp Canon A85. I was surprised
    (in some ways) that the old Fuji with a larger sensor simply put it to
    shame.

    Here is the test.

    http://home.att.net/~jriegle/megapix.htm

    I 'm thinking of comparing it to the A95 that has still more resolution and
    a bigger sensor than the A85.

    John
     
    JohnR, Oct 17, 2004
    #1
    1. Advertisements

  2. JohnR

    Wilt W Guest

    <<Fuji 3MP camera for one with more
    manual control, I got to compare it to the 4mp Canon A85. I was surprised
    (in some ways) that the old Fuji with a larger sensor simply put it to
    shame.>>

    Somehow the digital photography adopters have forgotten one very important
    fact: a photo is no better than the weakest link, and that weak like can often
    be the LENS. Funny how people buy cameras made by consumer electronics or
    computer companies who have NO history in OPTICS!
    Fuji has some highly respected large format lenses, and Canon has some
    terrific glass, too. But because one excels in the pro market, that does not
    ensure a terrific lens in all their P&S market products.

    --Wilt
     
    Wilt W, Oct 18, 2004
    #2
    1. Advertisements

  3. JohnR

    Drifter Guest

    In keeping with that same thought, a repost of something I wrote a
    while ago...

    Digital Cameras, A short analogy...

    Digital Camera Automobile
    ---------------------------------------
    Image sensor resolution……..Engine
    Processor...............Transmission
    Lens......................Tires
    Buffer....................Suspension
    Battery...................Gas tank
    Storage medium.....Trunk

    Lately advertisers are pushing "Megapixels" harder than ever as the
    standard measurement of how great their latest cameras are. With this
    Camera-to-Automobile analogy I am going to attempt to explain why
    "megapixels" alone is simply not enough to judge the superiority of a
    camera.

    The sensors (measured in Megapixels) keep increasing in resolution
    just like automotive engines increase in horsepower. However, all of
    the horsepower in the world is wasted if you have bald slippery tires
    (or a crappy lens). A car will just spin the tires and a camera will
    give you high resolution -but still blurry- images.

    The improved automotive engine gives you more horsepower, but if the
    transmission hasn't been beefed up to handle it you get a pile of
    scrap metal. The higher resolution camera gives you more information
    but if the processor hasn't been beefed up you get slower response and
    longer wait times while the processor tries to render the larger
    files. Thus you may miss shots.

    The same applies to the "Buffer/Suspension" parallel. A more powerful
    engine might be able to haul a larger load, but an undersized
    suspension will collapse under that load. So will a too-small buffer
    choke under the load of larger image sizes, causing extended waits.
    Etc, etc.

    My point is simply that a dramatic improvement in one aspect of a
    digital camera can be rendered absolutely moot if the rest of the
    digital system has not kept pace. So cameras need to be judged a bit
    more "as a unit" not just by one criterion (like pixel count).

    Like automobiles, which camera is right for you also depends on what
    you plan to do with it. A small Ford Focus is perfect for commuting
    around town just like a pocketable point-n-shoot is perfect for
    snapshots of the family reunion. But that same Ford Focus would not
    do very well in a rugged off-road environment just like that
    point-n-shoot would not work for photographing distant nesting eagles
    or trying to keep up with the action of a sports event.


    Drifter
    "I've been here, I've been there..."
     
    Drifter, Oct 18, 2004
    #3
  4. JohnR

    Bob Williams Guest

    Right you are John!
    The A 85 has a 1/2.7" sensor to handle 4MP. The 6800 has a 1/1.7" sensor
    (Super HAD) to handle 3MP. Each pixel site in the 6800 is considerably
    larger than that in the A85.
    For my money, pixel site AREA is of paramount importance.
    MP rating by itself is not a reliable criterion for determining image
    quality in a camera, but it sure is a wonderful marketing tool for
    selling to the great unwashed masses.
    Bob Williams
     
    Bob Williams, Oct 18, 2004
    #4
  5. On the other hand, the number of pixels is an easy metric for
    assessing at least the potential for THAT chain in the link.

    If we talk about resolution as used in film photography, that is a
    measured metric, then a camera that has ALL other items in the chain
    far better quality than the chip, then at best the camera would have
    an actual resolution capability of about 0.7 times the number of
    columns of pixels (horizontal resolution) and 0.7 times the number of
    rows (vertical resolution). However, even the chip can have problems
    that prevent it from obtaining the theoretical max resolution.

    Everything else being equally GOOD (admittedly a definitely
    weasel-wording), then a 4Mp camera would have higher resolution than a
    3Mp camera. However, if optics quality or any other link in the chain
    is really weak, this may no longer be true.

    Bad focusing system is a real gotcha. Hard to manually focus on the
    little bitty LCD screens on non-SLR digitals.
     
    Don Stauffer in Minneapolis, Oct 18, 2004
    #5
  6. JohnR

    DHB Guest

    Drifter,
    great analogy that most people can follow, especially since
    you went on to explain the parallels in detail. Outstanding effort to
    help us all understand digital camera technology better & make better
    choices as a result.

    If I may however, suggest adding 2 additional items to your
    analogy.

    Display....................Instrument cluster
    Features..................Driver controls

    My Digital Rebel/300D looks like this to me:
    Display....................Instrument cluster = Fair
    Features.................Driver controls = Poor

    Don't miss understand, I am very pleased with my Digital
    Rebel/300D DSLR, however it would be nice if it had more features like
    the 10D or 20D does but it is working very well for me now that I have
    taken the time to learn it's strengths & weaknesses & how to work
    around them. Saving up for the 30D or whatever they will call the new
    20D's replacement.

    Thanks again drifter, you obviously have collected a lot of
    knowledge & wisdom while drifting.

    Respectfully, DHB

    "To announce that there must be no criticism of the President,
    or that we are to stand by the President, right or wrong,
    is not only unpatriotic and servile, but is morally treasonable
    to the American public."----Theodore Roosevelt, May 7, 1918
     
    DHB, Oct 18, 2004
    #6
  7. JohnR

    Bob Williams Guest

    Provided that both sensors are the same size too.
    Smaller pixel sites do not capture as much image information and are
    inherently noisier than larger pixel sites, as others have mentioned.
    Sometimes it is better to trade off a little resolution for greater
    color depth and accuracy.
    However, in the OP's example, the 3MP Fuji image not only had better
    color than the 4MP Canon but also had better resolution.
    I am a very satisfied Canon Owner (S45) but I think they are stretching
    it a bit in the case of the A85 trying to cram 4MP onto a 1/2.7" sensor.
    Bob Williams
     
    Bob Williams, Oct 18, 2004
    #7
  8. JohnR

    Drifter Guest

    ---snip---
    ---snip---

    Thanks. I've been trying to make a collection of my thoughts and save
    them as easily re-posted documents to answer some of the common
    questions I see here. Some people appreciate the effort, others not
    so much <sigh>. Makes me glad when I help someone though.


    Drifter
    "I've been here, I've been there..."
     
    Drifter, Oct 18, 2004
    #8
  9. Those are great analogies, drifter. Can you think of a refined analogy
    the distinguishes a 6PM APS or 35mm-sized sensor from a 6MP
    compact-sized one? I think that a possible analogy might be the
    difference between a 300HP engine from the 1960's vs. a current 300HP
    engine - both have the same power, but vastly different pollution and
    efficiency charateristics.

    -Dave
     
    Dave Herzstein, Oct 19, 2004
    #9
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.