Resolution of digi pix vs film pix

Discussion in 'Digital Cameras' started by Jim Garner, Mar 2, 2004.

  1. Jim Garner

    Jim Garner Guest

    I have used my digi occasionally for pix that ended up in a newspaper,
    and there hasn't been any problem about quality. But I'm planning to
    talk to a local mag about some pix and I'm a touch worried about quality,
    and I'd like to get some comments.

    First, my focal length is approx one sixth that of an equivalent 35 mm
    camera. So I don't see how the digi can get OPTICAL resolution anywhere
    near that of a 35 mm -- unless the lenses supplied to a digi are vastly
    advanced (which may be the case, of course). Furthermore, it used to be
    that 35 mm photogs would use interchangeable, fixed focal length lenses
    becase they didn't think zooms good enough. Or is that belief now ancient

    The other question, of course, is pixellization. I recntly has occasion
    to blow up to 8-10 a digi pic that I had taken using only a quarter of the
    3.2 MP available (I hadn't known that I would be blowing it up and I'd set
    the camera to 1024 x 768) To my considerable surprise, I found no
    pixellization visible to MY naked eye.

    So, do I get magazine-quality pix from a digi and if so, how big?
    Jim Garner, Mar 2, 2004
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  2. Jim Garner

    Jeremy Guest

    I have a 2.3 MP camera, which was state-of-the-art back in 1999 when I
    bought it. I do not have an inkjet printer--I have OFOTO.COM make all my

    The 1200x1800 pixel sensor makes a perfect 4x6 print (assuming 300 p.p.i.)
    and I have seen no image degradation when enlarging to 5 x 7. I have had
    them do some 8 x 10s, and they came out very good, although it seems that
    the images weren't quite as bright as they looked on the smaller sizes.

    If you can settle for relatively smaller prints (4x6, 5x7) you will be
    pleasantly surprised at the sharpness and overall clarity that these
    under-powered cameras can deliver.

    I have a complete set of bodies (5) and lenses (13) for my film system, so I
    don't see much need to replace the digicam right now. If I were to buy
    another, it would need to be minimum 8 MP (8 x 10 prints at 300 ppi).

    I would offer you 2 suggestions:

    1: Try OFOTO.COM (a Kodak subsidiary) for some prints--they are made on real
    photo paper, not inkjet). I have been pleased with their results.

    2: So try to use a tripod, as it has a very discernable effect on sharpness.
    (I know that it looks strange--tiny camera on a tripod--but you'll get over
    it). I use my camera's remote control in place of a cable release--works
    great, and the shots are rock solid sharp.
    Jeremy, Mar 2, 2004
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  3. Jim Garner

    Chris Brown Guest

    The small sensor digicams do not need awkward retrofocus designs for these
    lenses. The elements are smaller and theer are likely to be fewer of them
    typically, so it should be easier to design a sharper lens when freed from
    the constraints of having to project onto a 35mm nbegative 50mm from the
    exit pupil.
    I tend to use primes rather than zooms, but the idea that they're vastly
    superior to (modern) zooms in terms of image quality is, IMO, overstated.
    AFAICS, the main reason to prefer primes is that they have larger apertures.
    I took a number of shots on my (digital) camera at the weekend using a lens
    wide-open at f/1.4 and got really nice results.
    If you upsample properly, rather than just scale the pixels, then the image
    should just get blurred as it is enlarged, rather than pixellated.
    There seems to be an emerging consensus that the 6 megapixel SLRs produce
    images at least as good as 35mm at 100 ISO, and considerably better at
    higher ISOs. There are a still a few "holdouts" who refuse to accept this,
    but more and more they're a minority. In general, the 6 megapixel SLRs will
    beat print film on resolution and beat slide film on dynamic range, again at
    100 ISO. It will give you "cleaner" results than either. Shoot at 400 ISO
    and there's nothing left to argue over - digital is so much better that it's
    not funny.
    Chris Brown, Mar 3, 2004
  4. While you are right about the higher ISOs, most serious articles put 6MP
    digital at about 60 to 70% of ISO 100 slide film resolution.

    If you look around either of these sites, you'll find lots of relevant stuff
    Exactly: except that I also like to point out that if one needs better
    resolution than 6MP dSLR, 35mm won't be good enough. For significantly
    better than 6MP dSLR, one needs medium format.

    The only excuse for 35mm is for wide angle.

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Mar 3, 2004
  5. Jim Garner

    Chris Brown Guest

    That sounds about right (for scanned stuff), but note that I specifically
    didn't say the 6 meggers best 35mm in all aspects, just that the images are
    at least as good. I think the important point is that if you want to make a
    large print, teh DSLR is alsmot always going to do a better job than 35mm
    film of any description, even when slides have a bit more recoverable detail
    in them.

    Having said that, projected slides are something else entirely.
    My own approach to this is to use a fisheye and then use Panotools to
    "defish" as appropriate. Gives me rectilinear images that have the same FOV
    as a 19mm lens on a 35mm body. There's also the added advantage that the
    fisheye doesn't vignette in the corners, which is really handy for stitched
    Chris Brown, Mar 3, 2004
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