Canon 650 IS vs SX 100 vs 720 IS

Discussion in 'Canon' started by Paulo Almeida, Jun 28, 2008.

  1. Hi,

    I'm looking to buy a new digital camera and I have narrow my search
    to 3 Canon models:

    650 IS

    I can get the 650 and SX100 for about the same price, and the 720 IS for
    a lower price.
    I've read the reviews in several magazines and all of them refer a "problem"
    with the 650IS related with its sensor resolution wich is 12 megapixels. But
    if I choose
    to shoot using the 3264x2448 resolution which is about 8 Megapixels could
    this problem
    be "solved". Also the 650 IS has a 1/1.7" sensor while the other two have a
    sensor. Shouldn't this allow it to compensate for the higher resolution?


    Paulo Almeida
    Paulo Almeida, Jun 28, 2008
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  2. Thank you for your answer.
    If I degrade the resolution from 12 to 8 megapixels on the 650 IS shouldn't
    I get a better picture? I am sure I don't need the 12 megapixels resolution.
    Paulo Almeida, Jun 29, 2008
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  3. Paulo Almeida

    John Guest

    What makes you think that Paulo?

    John, Jun 29, 2008
  4. John,

    Do your question refers to the "downgrade" of the resolution or to the need
    to use
    the 12 megapixels resolution?

    Regarding the use of the 12 megapixels resolution, the way I see it, you
    only need
    that resolution if you're going to print (very) large size pictures, which I
    I think I'm perfectly OK with 6 to 8 megapixels. If I could get a digital
    with the Canon 650IS specifications but with only a 6 or 8 megapixel sensor
    I would buy it. That's the reason in my original post I mentioned the Canon
    which has an 8 megapixel sensor.

    Regarding the "downgrade" of the resolution from 12 to 8 megapixels I
    thought that
    when you use a 3264x2448 resolution, which is about 8 Megapixels, since you
    are putting
    less pixels on the sensor, the picture should be better. I read an article
    somewhere where
    they say that a 6 megapixel sensor was the ideal for an 1/2.5" sensor. Above
    that number
    of pixels, increasing the megapixels but keeping the 1/2.5" creates a lot of
    noise and noise artifacts.
    Since the 650IS has a 1/1.7" sensor it should handle the 12 megapixels, but
    I thought that
    "downgrading" to 8 megapixels could produce better pictures.

    Best regards

    Paulo Almeida
    Paulo Almeida, Jun 29, 2008
  5. Paulo Almeida

    Dave Cohen Guest

    I agree with you insofar as I don't need and if I had a choice wouldn't
    go above 8mp. However, I doubt you would improve quality by shooting at
    a lower resolution. I suspect the noise is kept acceptable by limiting
    iso range. You would get a smaller file size but the higher mp would
    permit more cropping flexibility. If you needed a smaller final file
    size better to post process.
    Having said all that, I would get the camera for it's other features.
    The next step up would be a dslr or possibly G9. The mp count is
    somewhat of a marketing gimmick and we might as well get used to it
    since it's not likely to go away.
    Dave Cohen
    Dave Cohen, Jun 30, 2008
  6. Paulo Almeida

    John Guest

    I think you'll find the G9 is basically the same camera as the A650IS in
    that it has the same sensor, lens and possibly firmware to a point, so
    the end result would be very hard to see any difference between the two

    John, Jun 30, 2008
  7. Paulo Almeida

    Jeff R. Guest

    Dozens of reasons to prefer the G9, starting with (but not restricted to)
    the ability to save in RAW format.
    External flash, ISO dial, better batteries, humungous LCD and more.

    Specs may look similar on paper - but the two devices are miles apart in the
    Jeff R., Jun 30, 2008
  8. Paulo Almeida

    John Guest

    Did you read the bit were I said they were 'basically' the same. As the
    OP was talking about the end result.

    John, Jun 30, 2008
  9. Paulo Almeida

    Jeff R. Guest

    There are those about who would debate even "basically" when RAW vs
    jpeg-only is concerned. Not me, though.
    For me, the killer is lack of external flash - which I use constantly for
    bounce. Makes a helluva difference to the "end result".

    Jeff R., Jun 30, 2008
  10. Paulo Almeida

    John Guest

    Yes, but we're not talking about 'you' are we.

    John, Jun 30, 2008
  11. Paulo Almeida

    Jeff R. Guest


    Forget "me".

    Objectively there are significant differences.

    Happy now?
    Jeff R., Jun 30, 2008
  12. Paulo Almeida

    John Guest

    Yes, but not basic differences, which is what I said.

    John, Jun 30, 2008
  13. Paulo Almeida

    measekite Guest

    Cost more but the best of the three
    Does not have a viewfinder. To me it is important. Better to look at
    the S5IS. Better than all of them but a little larger.
    Best value. Has viewfinder and LCD. Good battery life. Takes all
    types 2AA and that is an advantage.
    When ever you cram more pixels on to the same size sensor you will get
    more noise. The A720 does just fine at ISO 200 or less and can produce
    a very good 5x7 cropped and even an 8.5x11 with moderate cropping.
    Better at ISO 100.
    The resolution of all of the cameras is not really a limiting factor.
    Your main enemy is noise.

    I chose a Canon S5 IS. I shoot as close to ISO 100 as circumstances
    allow with very little noise and get a nice 8.5x11 using a Canon IP4000
    printer with OEM ink. I do moderate cropping. The A720 (a friend has
    one on my recommendation) is almost as good but the S5 has more features
    and a lot longer lense. It also has an articulating LCD that I find
    beneficial for macro photography.
    measekite, Jul 2, 2008
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