Less zoom, more Megapixels?

Discussion in 'Digital Photography' started by Anthony Buckland, Dec 8, 2003.

  1. I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    camera.
    He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and
    as many Megapixels, say 5, as he could afford, on the theory that if he
    really
    wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    picture. Of course, the foreshortening would be different, but in
    general how do
    people in this group feel about this theory? Right now, the climb from
    lower to
    higher Megapixels seems cheaper than the climb to a high zoom, with many
    more
    choices.
     
    Anthony Buckland, Dec 8, 2003
    #1
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  2. Anthony Buckland

    Andy Hewitt Guest

    Anthony Buckland <> wrote:

    > I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    > camera.
    > He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and
    > as many Megapixels, say 5, as he could afford, on the theory that if he
    > really
    > wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    > picture. Of course, the foreshortening would be different, but in
    > general how do
    > people in this group feel about this theory? Right now, the climb from
    > lower to
    > higher Megapixels seems cheaper than the climb to a high zoom, with many
    > more
    > choices.


    It depends on what you need from the images. If it's for viewing on
    screen, or printing to A4 sheet, then surpassing 3MP has less benefit.
    Indeed an image edit experiment here, converting the image to 300ppi, I
    get a 28x21 inch image.

    If you need to consider more editing possibilities, or need to go larger
    at output, then higher Megapixels would be best.

    However, my personal choice is to go for better lenses. This is the main
    factor in image quality, although a good CCD is needed to capture that
    image too.

    There are arguments for both sides of course, and looking at it another
    way, it could be easier to shoot an image that is zoomed at source, as
    you could compose the shot more clearly, and maybe not even need to
    edit. I'm not sure of the exact maths involved, but it occurs to me that
    by rezooming later on, you have to zoom again by 3.333x on the already
    zoomed image. A quick calculation suggests that your method would make
    the final image far less than 3MP. In which case I'd say they're wrong.

    I've just tried this in an editing program, I simulated the zoom by
    reducing the size of the image by 33.33 percent, I ended up with a
    0.35MP image.

    Another thing to consider is that the depth of field is totally
    different too, so you wouldn't have the flexibility of composure you
    would with a true 10x zoom.

    Of course there is also the issue of zoom, rather than magnification!
    The zoom ratio is entirely dependent on the smallest focal length of the
    lens. Magnification is generally calculated from normal naked eye field
    of view (or more accurately the ratio between the focal length of the
    lens and the diagonal dimension of the CCD, or film).

    So, do you need to zoom in 10x, or magnify by 10x?

    Nope, I think I'll stick to optical zoom being my main buying criteria.

    --
    Andy Hewitt ** FAF#1, OSOS#5 - BMW K100RS 8v, Honda Concerto 16v
    Windows free zone (Mac G3)
    <http://homepage.ntlworld.com/ahewitt/index.htm> (last update 12.02)
     
    Andy Hewitt, Dec 8, 2003
    #2
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  3. Anthony Buckland <> writes:

    > I was talking to a friend with an older 10x optical zoom, 2 Megapixel camera.
    > He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and as
    > many Megapixels, say 5, as he could afford, on the theory that if he really
    > wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    > picture. Of course, the foreshortening would be different, but in general
    > how do people in this group feel about this theory? Right now, the climb
    > from lower to higher Megapixels seems cheaper than the climb to a high zoom,
    > with many more choices.


    I dunno, I generally like to frame my picture correctly the first time, rather
    than do it afterwards in a photo editor, but tastes vary.

    --
    Michael Meissner
    email:
    http://www.the-meissners.org
     
    Michael Meissner, Dec 9, 2003
    #3
  4. Anthony Buckland

    carpist Guest

    Andy,
    You are assuming a tripod will be used, yes? A hand held 500 mm in
    low light might suck just a bit. But shake is shake whether it is at 200
    or 500mm just not as apparent.
     
    carpist, Dec 9, 2003
    #4
  5. Anthony Buckland

    JackD Guest

    "Andy Hewitt" <> wrote in message
    news:1g5o8a3.1qjzettenyk74N%...
    > Anthony Buckland <> wrote:
    >
    > > I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    > > camera.
    > > He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom

    and
    > > as many Megapixels, say 5, as he could afford, on the theory that if he
    > > really
    > > wants a net zoom of 10 he'd shoot at 3x and then extract the center of

    the
    > > picture. Of course, the foreshortening would be different, but in
    > > general how do
    > > people in this group feel about this theory? Right now, the climb from
    > > lower to
    > > higher Megapixels seems cheaper than the climb to a high zoom, with many
    > > more
    > > choices.

    >
    > It depends on what you need from the images. If it's for viewing on
    > screen, or printing to A4 sheet, then surpassing 3MP has less benefit.
    > Indeed an image edit experiment here, converting the image to 300ppi, I
    > get a 28x21 inch image.
    >
    > If you need to consider more editing possibilities, or need to go larger
    > at output, then higher Megapixels would be best.
    >
    > However, my personal choice is to go for better lenses. This is the main
    > factor in image quality, although a good CCD is needed to capture that
    > image too.


    Here is where you advice starts to fall apart. Generally a 10x zoom will
    exhibit more distortion and give poorer image quality than one which is less
    extreme. This is the main argument for DSLR's and interchangeable lenses.

    -Jack
     
    JackD, Dec 9, 2003
    #5
  6. Anthony Buckland

    Ben Thomas Guest

    Anthony Buckland wrote:
    > I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    > camera.
    > He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and
    > as many Megapixels, say 5, as he could afford, on the theory that if he
    > really
    > wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    > picture. Of course, the foreshortening would be different, but in
    > general how do
    > people in this group feel about this theory? Right now, the climb from
    > lower to
    > higher Megapixels seems cheaper than the climb to a high zoom, with many
    > more
    > choices.
    >


    I was trying to choose between a 4MP 10x camera and a 5MP 3x camera, and decided
    that the 4MP camera would give me more flexibility when taking photos. Post
    processing takes a lot of time, and I'd rather get the photo composition right
    at the time that I take the photo.

    --
    --
    Ben Thomas - Software Engineer - UNICO Computer Systems
    Melbourne, Australia

    Opinions, conclusions, and other information in this message that do not
    relate to the official business of my employer, UNICO Computer Systems,
    shall be understood as neither given nor endorsed by it.
     
    Ben Thomas, Dec 9, 2003
    #6
  7. Anthony Buckland

    jam Guest

    For event, landscape and wildlife photography, where throwing as many
    pixels as possible onto a distant and unapproachable target is usually
    what counts most, I think your friend has it exactly backwards.

    If you do the math, you'll find that you can project more pixels onto
    your target (a bird, a singer's face, etc.) with a long lens than with
    a CCD with 2-3 times more pixels. Of course, the curves cross at some
    point, and you can calculate that point with the "figure of merit"
    described at

    www.cliffshade.com/dpfwiw/c-2000z/lenses/#merit

    I haven't done the math in a while, but I doubt that a 6MP CCD with a
    140 mm built-in lens would outperform a 3-4 MP CCD coupled to a 380 mm
    lens in this regard. The discontinued but sorely missed 2MP,
    image-stabilized 38-380 mm Oly 2100UZ still has a devoted following
    for a reason.

    Of course, if you go with a DSLR, you don't have to make this
    trade-off. Just add money.
    --
    Jeremy McCreary
    Denver, CO
    www.cliffshade.com/dpfwiw/
    -------------------------------------------


    "Anthony Buckland" <> wrote in message
    news:...
    | I was talking to a friend with an older 10x optical zoom, 2
    Megapixel
    | camera.
    | He said, and an overhearer agreed, that nowadays he'd choose a 3x
    zoom and
    | as many Megapixels, say 5, as he could afford, on the theory that if
    he
    | really
    | wants a net zoom of 10 he'd shoot at 3x and then extract the center
    of the
    | picture. Of course, the foreshortening would be different, but in
    | general how do
    | people in this group feel about this theory? Right now, the climb
    from
    | lower to
    | higher Megapixels seems cheaper than the climb to a high zoom, with
    many
    | more
    | choices.
    |
     
    jam, Dec 9, 2003
    #7
  8. Anthony Buckland

    Lew Guest

    To end up with the same pixels as 2MP, x10 zoom with a x3 zoom you need to
    have about 20MP before cropping. I use a x12 Panasonic with IS.
    Lew
    "Anthony Buckland" <> wrote in message
    news:...
    > I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    > camera.
    > He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and
    > as many Megapixels, say 5, as he could afford, on the theory that if he
    > really
    > wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    > picture. Of course, the foreshortening would be different, but in
    > general how do
    > people in this group feel about this theory? Right now, the climb from
    > lower to
    > higher Megapixels seems cheaper than the climb to a high zoom, with many
    > more
    > choices.
    >
     
    Lew, Dec 9, 2003
    #8
  9. Anthony Buckland

    Guest

    In message <br36l7$mds$>,
    "JackD" <> wrote:

    >Here is where you advice starts to fall apart. Generally a 10x zoom will
    >exhibit more distortion and give poorer image quality than one which is less
    >extreme. This is the main argument for DSLR's and interchangeable lenses.


    What would be really nice would be a camera that took Canon or Nikon
    lenses, and used a small-form sensor with 5mp, like that used in the
    F717 or the Minolta DiMage7 series, to make good use out of the sharp
    telephotos. My Canon 300mm f4L IS lens can resolve at least 2.5x what
    my 10D sensor can handle, and the 10D has a fine a pixel pitch as any
    DSLR. The lens would be like a 900mm (35mm-equivalent), without any
    teleconverters and their loss of contrast. Of course, it would only be
    good in bright light where ISO 100 could be used.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    , Dec 9, 2003
    #9
  10. Anthony Buckland

    Mark Herring Guest

    On Mon, 08 Dec 2003 14:13:06 -0800, Anthony Buckland
    <> wrote:

    >I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    >camera.
    >He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and
    >as many Megapixels, say 5, as he could afford, on the theory that if he
    >really
    >wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    >picture. Of course, the foreshortening would be different, but in
    >general how do
    >people in this group feel about this theory? Right now, the climb from
    >lower to
    >higher Megapixels seems cheaper than the climb to a high zoom, with many
    >more
    >choices.


    Here's a perspective:

    First, get "enough" Mpixels for your desired print size: 2MP for 4x6,
    3-5 MP for 8x10

    Second, get the best lens you can find. Not just zoom, but minimum
    f/#, sharpness, etc.

    Then, get a long zoom---but not at the expense of 1 and 2.

    If you are at your minimum file size for your printing needs, then a
    longer zoom will help you more than will more pixels
    **************************
    Mark Herring, Pasadena, Calif.
    Private e-mail: Just say no to "No".
     
    Mark Herring, Dec 9, 2003
    #10
  11. Anthony Buckland

    Mark Johnson Guest

    Anthony Buckland <> wrote:

    >I was talking to a friend with an older 10x optical zoom, 2 Megapixel
    >camera.
    >He said, and an overhearer agreed, that nowadays he'd choose a 3x zoom and
    >as many Megapixels, say 5, as he could afford, on the theory that if he
    >really
    >wants a net zoom of 10 he'd shoot at 3x and then extract the center of the
    >picture. Of course, the foreshortening would be different, but in
    >general how do
    >people in this group feel about this theory? Right now, the climb from
    >lower to
    >higher Megapixels seems cheaper than the climb to a high zoom, with many
    >more
    >choices.


    Zoom could mean less light. If you use the 'digital/software' zoom
    crop-in-camera, then you can have loss of detail and fuzziness. If
    re-sharpening can get that back, no loss. If it can't. That assumes a
    perfectly still camera, or very fast shutter. But you need a lot of
    light for a faster shutter. On the other hand, with zoom, you can
    actually see the shot. Otherwise, you might be guessing what the
    camera sees. I assume the trade-off you're suggesting is pulling back
    and cropping later, or zooming in to fill the screen and hoping you
    can follow the action and maintain focus.

    On the other hand, if there is a 'sweet spot' in not zooming so much,
    or messing with telephoto lenses, particularly those huge jobs the
    photogs drag with them to sporting events so they can see the shot up
    close, then I don't know that 5MP is enough to forego zoom. But a
    $400-500 10MP digicam might be, if they come down to that by the end
    of next year.

    One might imagine that a 10MP image, which might be 15Meg or more in a
    RAW format, would pose a problem. But the cards are getting cheaper.
    Faster computers with a lot of memory are dirt cheap. You can always
    review, in camera, and delete shots that just didn't quite get it, and
    try again. With enough flash memory and some way to offload it in the
    field, I don't know that such would be considered even a bit
    unmanageable.
     
    Mark Johnson, Dec 9, 2003
    #11
  12. Lew wrote:

    >To end up with the same pixels as 2MP, x10 zoom with a x3 zoom you need to
    >have about 20MP before cropping. ...
    >


    You're right, of course, and even without my math BSc (wince) I should have
    been able to figure out that a zoom-by-crop of nx leaves you with 1/n^2 as
    many pixels. So, where the friend now uses 10x optical zoom and has 2MP
    in the picture, with a 3x optical zoom and 5MP he would have had to crop
    to a picture with 460KP, not good.
     
    Anthony Buckland, Dec 9, 2003
    #12
  13. Anthony Buckland

    Andy Hewitt Guest

    JackD <> wrote:

    <Snipped Text>
    > Here is where you advice starts to fall apart. Generally a 10x zoom will
    > exhibit more distortion and give poorer image quality than one which is less
    > extreme. This is the main argument for DSLR's and interchangeable lenses.


    Indeed, but then you quadruple your costs as well. I believe we were
    talking about compacts here. I appreciate that a zoom lens is not as
    good as a fixed focus lens, but a lot can depend on the lens quality
    too.

    FWIW, all digital cameras suffer with distortion anyway as the light
    doesn't hit the CDD at right angles - only the new Olympus E1 system has
    got this so far.

    Of course the cropping method would reduce the distortion somewhat, but
    you're not zooming the image, you're only cropping it, and ending up
    with a much smaller image.

    --
    Andy Hewitt ** FAF#1, OSOS#5 - BMW K100RS 8v, Honda Concerto 16v
    Windows free zone (Mac G3)
    <http://homepage.ntlworld.com/ahewitt/index.htm> (last update 12.02)
     
    Andy Hewitt, Dec 9, 2003
    #13
  14. Anthony Buckland

    Andy Hewitt Guest

    carpist <> wrote:

    > Andy,
    > You are assuming a tripod will be used, yes? A hand held 500 mm in
    > low light might suck just a bit. But shake is shake whether it is at 200
    > or 500mm just not as apparent.


    Indeed.

    --
    Andy Hewitt ** FAF#1, OSOS#5 - BMW K100RS 8v, Honda Concerto 16v
    Windows free zone (Mac G3)
    <http://homepage.ntlworld.com/ahewitt/index.htm> (last update 12.02)
     
    Andy Hewitt, Dec 9, 2003
    #14
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