DSLR v Consumer Image quality

Discussion in 'Digital Photography' started by oink, Feb 22, 2005.

  1. oink

    rafe bustin Guest


    I do that as well. It puts these puny
    6 Mpixel DSLR images in perspective.


    rafe b.
    http://www.terrapinphoto.com
     
    rafe bustin, Feb 23, 2005
    #41
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  2. What you are saying is the dynamic range of the sensor,
    not the signal-to-noise ratio of a single pixel.
    They two specifications are different.

    Roger
     
    Roger N. Clark (change username to rnclark), Feb 23, 2005
    #42
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  3. oink

    rafe bustin Guest


    Print size matters, of course. I have an
    Epson 7000 at home, so I can do 24" wide
    prints.

    I believe you're saying the monitor is
    perhaps "overly critical" and there is
    much truth to that -- many flaws visible
    on the monitor will be invisible in print.


    Hogwash. It's entirely relevant. If the
    monitor lacks focus or is misadjusted for
    gamma, you will lose detail, and will be
    surprised by what you see in print. If
    you're doing digital darkroom work on a
    cheap uncalibrated monitor at 600 x 800,
    you're in for a rough ride.

    Constant, yes. But having the effect of
    masking or obscuring and generally degrading
    the original image. For example, there are
    very few print technologies that can match
    the Dmax or gamut of a good monitor, and
    inkjet prints are far from being "continuous
    tone." The ubiquitous "banding" seen on
    many inkjet and dye-sub printers has no
    parallel on a monitor.


    I bin stuff for any number of reasons,
    some technical, some not. A large part
    of art is knowing what to keep and what
    to toss.


    rafe b.
    http://www.terrapinphoto.com
     
    rafe bustin, Feb 23, 2005
    #43
  4. By your argument, one only needs a small patch of high resolution
    data in the center inch or so of an 8x10 print (e.g. about 1 inch
    in diameter) and the rest can be fuzzy. Obviously the
    eye+brain see more than that. Your eye wanders around
    even if you are not aware of it. As you view a scene,
    you move your eyes around to see all the detail.
    This is true whether looking at a photographic print,
    or looking at a real scene. Stand outdoors and examine
    a real scene and the wealth of detail you can see all around you.
    Now produce a photograph with that same detail: the detail
    you can see with your eyes in the real world. It can't be
    done with a digital camera, 35mm film, or medium format
    film. One needs large format film, and 4x5 fine grained
    film is about the minimum, and even then it does not have the
    detail you experience with one's full field of view.
    If you've never seen a big large-format print, at the next
    opportunity, do so. It can be like looking
    out a window to the real scene.

    Roger
     
    Roger N. Clark (change username to rnclark), Feb 23, 2005
    #44
  5. oink

    Chris Brown Guest

    I gave it and bought one last weekend. It's a great old thing, MPP VI,
    upgraded to VII spec with the rotating international back. Two days ago, I
    shut myself in my bathroom, blocked the gap under the door, turned out all
    the lights, and loaded my first sheet of film. That was a bit of an
    intimidating experience - I knew vaugely what to expect after unsealing the
    box, but having to do it all in total darkness by feel alone was kind of
    daunting. I'm hoping it'll get easier with experience. I also got a rollfilm
    back for 6*7, for when I'm feeling too wimpy to use sheet film.

    So far, I have spent hours playing with the camera, but have yet to take a
    single exposure. How many digital cameras can you say that about? ;-)

    I expect I'll be taking a picture this weekend - probably a macro of a dried
    flower using the triple extension. I'm hoping my friendly local lab won't
    mind me just dropping the dark slide off with them, otherwise I have no idea
    how I'm going to get this processed. I don't especially fancy setting up my
    own E6 darkroom.

    My wife has decided that we are calling the camera, "Snapper", because
    something with so much character needs a name. This is not because we expect
    to use it to make expensive snapshots, but because the thing essentially
    seems to be a load of springs held in formation by willpower, which leap out
    and "snap" at the unwary.

    Not entirely sure what I've got myself into here...
     
    Chris Brown, Feb 23, 2005
    #45
  6. oink

    Owamanga Guest

    Except by these standard of arguments, the print will only have about
    1/5th of the dynamic range that an eye can handle, plus information
    for only one eye (eg, no 3D data). By this argument, it's hardly
    convincing - of course in reality our brains ignore all that stuff and
    those prints do look amazing.
     
    Owamanga, Feb 23, 2005
    #46
  7. oink

    C J Campbell Guest

    C J Campbell, Feb 23, 2005
    #47
  8. oink

    Owamanga Guest

    It's been my experience that focus on modern monitors is rarely bad
    enough to affect final-print image quality, especially if you want to
    work at 200% zoom. I don't do focus corrections in Photoshop - in
    fact, I wouldn't know where to start, so the focus or lack of isn't
    going to change what I do to the image. On all LCD displays this is a
    non-issue.

    By this logic, would you argue that people without 20-20 vision can't
    cull images properly too?

    Color balance won't affect output quality, other than you'll get a
    mis-balanced print. But that's not what we are talking about here - we
    are talking resolution, and the need (or not) to critic at 200% or
    even 100% zoom.
    Again this doesn't matter. If that's what your output technology is
    limited to, then that's what we are striving for. Quality stops there.

    Imagine if we only had monochrome printers, you'd be arguing that
    color balance is still relevant - of course, it isn't
    ..
    So you would agree, I hope, that a minor fault on a 6Mp image that can
    only be seen at 200% zoom is not relevant for 99.9% of users, because
    that's the real situation.
     
    Owamanga, Feb 23, 2005
    #48
  9. oink

    C J Campbell Guest

    In what way is it better? Why does the small sensor of the human eye have
    better resolution than the large sensor of a 35 mm frame?
     
    C J Campbell, Feb 23, 2005
    #49
  10. oink

    Owamanga Guest

    Agggh! but the whole point of capturing the image (in *most* people's
    use of a DSLR) is to PRINT IT.

    Yes, gamut gets compressed, yes data gets discarded, yes the frame
    gets cropped slightly, yes a paper texture is introduced, yes
    reflected chemical or pigment prints look different to
    backlight-screen images. But we *accept* all of that because the final
    product IS THE PRINT.

    ...if we can't see the defect in the print, then there *is no defect*.
     
    Owamanga, Feb 23, 2005
    #50
  11. oink

    rafeb Guest


    It pains me to admit it, but there is
    a good deal of truth to this.

    Too bad LF is such a pain in the butt,
    and so damned slow and expensive.

    You couldn't find two more diametrically
    opposed approaches to photography --
    digicams and LF.

    What's equally annoying to me is that,
    of my large prints, most of those that
    my wife prefers come from the 10D.



    rafe b.
    http://www.terrapinphoto.com
     
    rafeb, Feb 23, 2005
    #51
  12. oink

    Martin Brown Guest

    Upto around 6Mpixels image quality undoubtedly improves.

    But more pixels on the same sized area of silicon produces a trade off
    in dynamic range and signal to noise that starts to be an issue around
    8-10Mpixels on the current die sizes and manufacturing tolerances.

    A physically larger sensor with more pixels would always be better, but
    with ever more pixels on the same size chunk of silicon eventually you lose.
    The more pixels there are the smaller the capacitance of each pixel well
    - lower dynamic range and more susceptibility to noise.

    Regards,
    Martin Brown
     
    Martin Brown, Feb 23, 2005
    #52
  13. oink

    rafeb Guest

    I can't speak for 99.9% of users.

    Mostly what I thought we were discussing is
    whether 100% viewing on screen was useful or
    not. I maintain that it is, for critical
    work, or for large prints. In my experience --
    while the print is the end goal, the monitor
    is a pretty good predictor of how good the
    print can be. If detail or tonality aren't
    there on the screen, they're not going to
    magically appear on the print.


    rafe b.
    http://www.terrapinphoto.com
     
    rafeb, Feb 23, 2005
    #53
  14. oink

    rafeb Guest

    C J Campbell wrote:


    The human eye has this thing called
    a brain behind it. The human eye has
    great resolution over a very small
    viewing angle. But the brain can direct
    that super-sensitive area (the fovea)
    instantly to where it's needed.

    In many ways the human eye is a pretty
    poor design. Light actually has to
    pass through a layer or two of neural
    processing tissue before it lands on
    the retina!



    rafe b.
    http://www.terrapinphoto.com
     
    rafeb, Feb 23, 2005
    #54
  15. oink

    Owamanga Guest

    Well, these are the people who print 200 4x6's for every one 8x10.
    These people have never had a 5ft wide print made. These people
    wouldn't attempt to critique another person's 5ft print at a distance
    of 15 inches. Normal, non-pros with cameras, that take photos of
    every-day stuff.
    But you can see tonality at 20%.

    The detail you can only see by zooming to 200% just isn't going to be
    visible on an 8x10. (I mean, we are talking about stuff like jpeg
    artifacts here, you *can't* see them on the prints, yet they are
    clearly visible at 200% on a screen).

    There's nothing overly wrong with occasionally critiquing at 100% or
    more if the possible destination print dimensions require that, but in
    many cases it's like a bank teller who uses an electron microscope to
    check your signature. A fine waste of time.
     
    Owamanga, Feb 23, 2005
    #55
  16. oink

    rafeb Guest

    Owamanga wrote:

    Well, actually a lot of folks claim that
    they're not interested in prints, but
    rather in seeing their images on a CRT.
    I'm not one of those, but it's yet
    another way of "seeing" things.


    Seems like a narrow point of view, but
    maybe OK for "99.9% of users."

    This argument presumes that printing
    technology is static (and this includes
    printer, papers, and ink) or that your
    printing skills are static, or that you'd
    never want to see the same image in a
    larger print.

    I've been involved in the "digital darkroom"
    for about seven years now. I started out
    having great fun scanning 35mm film and
    making 8x10" prints on an Epson 600.

    At this point I'm shooting everything from
    35mm, a 10D, a G2, MF and LF film, and
    printing on an Epson 7000, or LightJet,
    Chromira, or Durst Epsilon. Maybe someday
    I'll have an Epson 9600 or a Roland or
    Colorspan... who knows where this
    insanity will end?



    rafe b.
    http://www.terrapinphoto.com
     
    rafeb, Feb 23, 2005
    #56
  17. oink

    C J Campbell Guest

    That explains absolutely nothing. You are saying that the human eye performs
    better, despite its deficiencies, because it has better software? Well then,
    why can't better software improve the picture on a small digital sensor?
    The eye in this respect is nothing but an extension of the brain. Rods
    provide very rough resolution, but tremendous light sensitivity, reacting to
    a single photon. The individual rods, however, are poorly connected; often
    three or four rods connected to a single pathway. This inefficiency is
    probably an advantage in helping to reduce noise.
     
    C J Campbell, Feb 23, 2005
    #57
  18. oink

    C J Campbell Guest

    Does it indeed? So how does the eye achieve that resolution with only 6
    million cones and somewhere between 100 million and 200 million rods -- most
    of which are duplicates or not connected to anything? Maybe Mr. Clark needs
    to check his figures again.
     
    C J Campbell, Feb 23, 2005
    #58
  19. oink

    Scott W Guest

    The problem is that it is easy to fool yourself into thinking there is
    useful detail in a photo when there is not, when viewing it at 100% on
    screen. The reason for this is simple, at 100% on screen you will see
    low contrast detail because it will be fairly low in lines per inch,
    but when printed this low contrast detail is no longer visible to the
    human eye.

    The eye can see detail to 0.7 line pairs per inch for 100% contrast, at
    a light level of 23 foot lamberts, this drops to 0.4 line pairs per
    inch at 10% contrast. And you can see down to less then 2% contrast if
    the line pairs per inch are at 0.1.

    What all this means is that you will see detail on the screen that you
    will not see in the print.

    So you are correct detail will not magically appear when printed, but
    it will disappear.

    Scott
     
    Scott W, Feb 23, 2005
    #59
  20. I was in exactly this situation. I had a compact zoom film camera and
    wanted to "go digital" (well, go "properly" digital -- I did have a
    few-years-old 1+MP p&s, but I'd stopped using it).

    Probably the main criteria was to get something "pretty decent" that would
    do most of things -- at least reasonably well -- that I'd be likely to want
    to do for some time to come.

    For little more reason than I spotted a second-hand one in a shop, and it
    looked "nice", I originally started looking at the Nikon 8700. Browsing
    around the web, I was then toying between it and the 8800 (it cost more,
    but had stabilisation). Almost on the verge of buying one or other of
    these, I then stumbled across (among other sites) one of Ken Rockwell's
    pages where he basically said the same as you: If you're going to spend
    your money on [any of the 4 or 5] 8Mp prosumer fixed-lens cameras, you're
    probably better spending a little bit more and getting a lower-end dSLR
    (better noise, startup- and shooting-speeds etc.).

    In my particular case, I also went with his (and others') opinions of the
    D70 being preferable/better to the dRebel, but this isn't a Canon v. Nikon
    argument -- the important issue is high-end p&s v. low-end dSLR.

    Although I've not had as much chance to do as much shooting as I would like
    to yet, I'm convinced I made the right choice. The D70 (in my case) allows
    much greater freedom for whatever directions my future photographic desires
    will take me than one of the high-end p&s would have done. I may never use
    all the potential, but at least I know it's there!

    Regards,
    Graham Holden (g-holden AT dircon DOT co DOT uk)
     
    Graham Holden, Feb 23, 2005
    #60
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