6 or 8 MPIX?

Discussion in 'Digital SLR' started by Chuck Deitz, Mar 4, 2005.

  1. Chuck Deitz

    Chuck Deitz Guest


    I'm looking at something like a Minolta A1 or A2, or Panansonic Lumix FZ5.

    I also see cameras like the Canons 300D, 20D, 350, Nikon D70, Pentax
    *istDS and Minolta 7 on some websites.

    Is 8 Mpix really that much better than just 6? I want to make prints up
    to a sheet of paper on my inkjet, but mostly smaller, like from the

    Are Nikon and the others going to have 8 Mpix SLR cameras soon? (They
    all seem to have 8 Mpix in the other cameras like the Minolta A2, the
    Nikon 8400 and so on, so why not on the SLR's? (I know the sensors are
    different but if Canon are doing it where's Nikon and the others?).

    I have a film rebel, but I don't use it much.

    What lens should I get? I just need something to take on a vacation
    with the familly and stuff like that. I'll probably use it at work too.
    Some of them come with lenses so I'll probably just do that. One of
    the Canon 300 kits has a 18-55 lens. Is this okay? Can I use my Rebel
    lens instead? 28-80.

    I also have a Canon flash, but I don't know the model, it's about 5
    years old. can I use it if I get a 300 or the new 350D.


    Chuck Deitz, Mar 4, 2005
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  2. It's fine. It's not the world's best lens, but there seems to be
    a consensus that it's a good deal for the money. I have one -- I
    don't find myself using it very often, but your mileage may vary.
    I don't think you'll find a lens that wide for cheaper.
    Yeah. On any low-to-mid-range Canon DSLR (10D, 20D, 300D, 350D),
    it'll seem like a longer lens -- about 45-128. If you like the
    28-80 range, then go with the 18-55, as it gives a similar field
    of view (29-88, roughly) on the digital cameras.

    Note that the 18-55 only fits on the digital Rebel and the 20D. You
    can't use it on your film camera.
    Dunno, sorry.
    Ben Rosengart, Mar 4, 2005
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  3. Chuck Deitz

    Chuck Deitz Guest

    Chuck Deitz, Mar 4, 2005
  4. Chuck Deitz

    bmoag Guest

    Many people who post on digital camera newsgroups have limited or no real
    experience with high end EVF (electronic viewfinder cameras like the Sony
    828, Nikon 8800 et al) cameras but they have a lot of opinions.
    The main drawback as well as the main asset is the EVF as for most people
    the zoom lens is of sufficient range and quality. If you do not understand
    why the lens diaphragm is limited to f8 then it should not be of any concern
    to you whatever.
    Also those who have not worked extensively with images created from these
    8mp sensors have absolutely no idea how stellar the images can be compared
    to 6mp dSLRs.
    If you want to see noise, moire and fringing pick up a D70. Because I am
    used to a lifetime of using SLRs I tend to use my D70 more than my Sony 828,
    but in general I prefer the image quality from my Sony 828. However because
    of the lens, which is of excellent quality and effectively maintains f2.8
    through its zoom range, the 828 is much heavier than other EVF cameras in
    its class.
    The extra 2mps of an 8mp sensor make a real difference in image detail and
    sharpness prior to applying software sharpening.
    In fact, if one wants a dSLR I think it unwise to buy anything other than
    the new 8mp Canon dSLR (unfortunately I have a shelf full of Nikon lenses).
    Nikon has not let out any information about their upgrade for the D70/D100
    but market conditions demand it be out in time for the next Christmas buying
    cycle and compete with Canon's upgrade to 8mp sensors.
    It is not clear who is manufacturing the 12mp sensor for the new high end
    Nikon dSLR (Sony? Mitsubishi?) or whether this will be the basis for Nikon's
    upgrade of their consumer dSLR line.
    An EVF allows one to preview what happens with exposure adjustments prior
    to taking the picture, e.g exposing for the highlights or the shadows. This
    can be very helpful as well as instructive.
    However it can be difficult to track moving objects or to use an EVF in very
    bright sunlight: sometimes one can only guess when to press the shutter
    button. This is probably not an issue for most casual users.
    EVF cameras handle much more slowly than dSLRS, most of which, like the D70,
    handle almost as quickly as film SLRs.
    If you do not want an SLR style/size/weight camera do not hesitate to get
    the EVF camera of your choice. It will allow you to grow into digital
    photography much more readily than any P&S style digicam.
    bmoag, Mar 4, 2005
  5. Chuck Deitz

    G.T. Guest

    You mean the extra 2mps shoved into a smaller sensor make a real difference
    in noise? Maybe my co-worker has a bad 828 but it is noisy.

    G.T., Mar 4, 2005
  6. Chuck Deitz

    Stacey Guest

    G.T. wrote:

    You assume everyone gauge of image quality is noise. Also noise can be
    easily fixed if an image is worth printing, lack of resolution and detail
    OTOH can't be. I'd much rather see an image "saved" with some good NR
    rather than being over sharpened.
    Stacey, Mar 4, 2005
  7. Chuck Deitz

    Stacey Guest

    Let me guess, you own a 6MP camera? :)

    Yea your right, 33% again the amount of pixels isn't going to help the
    resolution is it?
    Stacey, Mar 4, 2005
  8. Chuck Deitz

    Brian Baird Guest

    No, it really won't.

    33% more pixels does not equal a 33% increase in resolution. More like
    10-12%. Not to say that 10-12% is insignificant, but it isn't so large
    as to make one superior and the other useless.
    Brian Baird, Mar 4, 2005
  9. Nope, 8.
    Not for the O.P.'s needs, no.
    Ben Rosengart, Mar 4, 2005
  10. Chuck Deitz

    Stacey Guest

    Didn't say that but maybe you can explain why it would be only a 10%
    increase is resolution? Seriously I'm not being a smart ass, just wondering
    why it wouldn't be closer to the same as the increase in pixel count,
    especially at low ISO's.

    But if the optics can deal with it, 10-15% isn't anything to sneeze at.
    Stacey, Mar 4, 2005
  11. The O.P. wants to make drugstore prints and an occasional 8x10.
    I'm not saying he shouldn't get an 8MP camera, I'm just saying
    that the 6MP DSLRs are up to the task.

    This isn't some kind of anti-8MP bias. I'm trying to unload a used
    Olympus C-8080, so if I were going to be dishonest, I'd say everyone
    needs an 8MP camera. :) But look, from 6 megapixels you can print
    8"x10" at a very respectable 270 dpi. For 4x6s or 5x7s 6MP is
    higher resolution than the print.
    Ben Rosengart, Mar 4, 2005
  12. Stacey wrote:
    6Mp or 8Mp is a count within the sensor area, so the linear density in
    each axis only goes up by the square root in the area density, 15.4% in
    this case.

    From what I've read, however, the better signal-to-noise ratio in a
    digital SLR makes their 6Mp pixels look better than the pixels from an 8Mp
    point-and-shoot, so that to the eye the extra resolution may (or may not)
    be outweighed by the worse signal-to-noise.

    It's one of those subjective comparisons, and why some people may prefer
    film, which also has a higher resolution and higher noise (grain), to

    David J Taylor, Mar 4, 2005
  13. Chuck Deitz

    Stacey Guest

    So this "15%" is based on about linear improvement? I thought someone was
    saying that the 2D image quality would only improve by 1/2 the increase in
    pixels, that didn't make sense. I can see what you mean that the linear
    increase (Lpmm) wouldn't increase 33%.
    I'm sure that's true. I'm not sure on the larger APS size sensors that the
    noise increase would be too much.
    Stacey, Mar 4, 2005
  14. Stacey wrote:
    For a given sensor size, the trade-off in number of pixels isn't obvious.

    - If you, say, quadruple the number of pixels, the area of each is
    quatered, and the noise goes up proportionately. How does the eye react
    to having more pixels but with each pixel being noiser?

    - If you halve the pixel-to-pixel centre spacing (to double the number of
    pixels in both X and Y dimensions), then there may be a certain fixed are
    required per pixel for readout electronics etc., so the smaller pixels may
    do worse than you expect, as the readout area is a greater fraction of the
    pixel area.

    - If you produce a new sensor with these smaller pixels, likely something
    else in the process or design has improved, so you may recover some of
    that loss due to smaller area!

    The way things are measured right now, you end up needing a final subject
    judgement about whether you prefer A or B.

    David J Taylor, Mar 4, 2005
  15. Chuck Deitz

    Brian Baird Guest

    You're equating a factor measurement with a linear one.

    The number of pixels increases at a rate higher than the linear
    dimensions of the file produced. Since resolution is a feature of
    spatial frequency it relies on the number of rows and columns.

    To make the example simple, let's imagine a square 3x3 sensor. It
    produces 9 pixels (3 x 3) and can't resolve much. Now, compare that to
    a 4x4 sensor, which has 16 pixels (an increase of 78%) but only one
    additional row and column of pixels for a slight increase in resolution.

    It gets a little more complicated when you're dealing with rectangular
    sensors of differing aspect ratios, but the basic concept is the same.
    In order to record more data over the entire plane, you have to record
    more data at each row/column. That adds up fast while the total amount
    of resolving power of the sensor is increased only slightly.
    Brian Baird, Mar 4, 2005
  16. Chuck Deitz

    Darrell Guest

    the number of pixels isn't the whole answer. I can take an 8 megapixel Canon
    Pro 1 and the 6.3 megapixel image from a Digital Rebel (300D) will be
    better. I hear it every day in the store, well that's 8 MP so it's better.
    Sensor size and quality has to be considered.
    Darrell, Mar 4, 2005
  17. Chuck Deitz

    Chuck Guest

    get the 350D. You already have a lens for it and it will be an ecxellent
    Chuck, Mar 4, 2005
  18. Chuck Deitz

    Chuck Guest

    "10-12% is insignificant, but it isn't so large
    yeah you area a smart ass...
    Chuck, Mar 4, 2005
  19. Chuck Deitz

    Alan Browne Guest

    For "mostly smaller", 6 Mpix is more than enough; for 8x10 or 8.5 x 11,
    Mpix is sufficient. If the dollar difference makes no difference to you
    then simply go for the 8 Mpix.
    Canon have their own sensor design capability and are close to the
    fabricator (if indeed they don't fabricate themselves). Nikon, Pentax
    and Minolta get their sensor from Sony, so they're slaves to Sony's
    desires and pace.
    Sure. On a 300D it will crop out to seem like a 44-127mm.
    I don't believe the older flashes work properly on the digital cameras,
    although in manual mode it might... then you have to set the flash power
    per an incident flash meter reading or via a chart.

    Alan Browne, Mar 4, 2005
  20. Chuck Deitz

    Alan Adrian Guest

    One advantage of 8MP over 6MP is your cropability.... I know I'm always
    taking a simpler, better image out of the taken one. By having a 20D I can
    go deeper, and still print at 20cm x 30cm.

    I agree that you don't even need 6MP for making 10x20's, and If I were
    offered a choice between a quick 6MP and a slow 8MP I'd go for the quicker
    working camera.... Fortunately it's not a decision if you go with the two
    Canon 8MP right now... The write time is very quick on the 20D (and I assume
    it will be on the 350XT as well).

    As far as the 18-55 kit lens from Canon. My first copy was not great, but
    I'm very happy with the replacement. I don't use it that much, but it does
    take decent images... especially for the price I paid to have it.

    Alan Adrian, Mar 4, 2005
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