Fuming mad, unscheduled replacement camera suggestions?

Discussion in 'Photography' started by bad sector, May 30, 2012.

  1. The trick is to learn to produce the correct view during
    shooting. Then you either have 24 MPix for printing or
    everything will be fine with much less MPix.
    Obviously, you want to buy used bodies then. :)

    Lenses loose their value slower --- and good ones can also be
    had used.

    Wolfgang Weisselberg, Jun 2, 2012
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  2. bad sector

    bad sector Guest

    canon sx230?

    1080p HD, manual overrides, large pocket size and since it's a year on
    the market prices have retreated some ($230-300). I never had a Canon
    but the reviews are generally good.
    bad sector, Jun 4, 2012
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  3. PDAF (Phase Detect AF) is "less accurate" because it measures
    from a secondary, specialized sensor[1] --- and the optical path
    to said secondary sensor needs to be identical[2] in length to
    the main sensor. There's influence from the lenses (that's how
    microfocussing works: set an offset from the rays passing through
    the lens to the secondary sensor, often by lens and focus length.
    I.e. in theory it's as accurate as CDAF (Contrast Detecion AF) ...

    People put up with this kind of crap because it's *much* much
    faster than CDAF, handles low light well, and can properly track
    and predict subject movement.


    [1] There are apparently ways of using PDAF on a main sensor,
    but that entails sacrificing several 10.000 perfectly working
    green pixels by half-covering them. I doubt that's in
    production yet.

    [2] or corrected for the difference
    Wolfgang Weisselberg, Jun 4, 2012
  4. Yes. And different for each focus point, and different for each shot
    (since the main and secondary mirrors won't return to *identical*
    positions each time).

    I'm referring to the entire system in practice when I say it's less
    accurate -- that's what actually matters to those of us discussing
    taking pictures with actual cameras.
    It's faster, in particular, because the sensor output identifies which
    direction the subject is out of focus in, so the camera never has to
    guess, and never guesses wrong and has to reverse. And it's just
    inherently fast, too, doesn't have to read volumes of data from the main
    chip and then analyze it.

    It's still a total kludge; kinda like the internal combustion engine.
    It's so highly developed that it actually mostly works most of the time.

    I'm not sure how much of the tracking is based on that. The appearance
    of face-detect AF on DSLRs is based on another sensor able to get enough
    information for face detection, the actual PDAF sensors can't.
    There are a few out there, I've seen info on dpreview It hink.
    David Dyer-Bennet, Jun 4, 2012
  5. bad sector

    bad sector Guest

    As an example today while working on my driveway a good 75-100 seagulls
    were swarming all over the backhoe-loader while I had both hands more
    than full (for 10 hours). They ate the worms that became uncovered,
    sofar nothing spectacular. But a wind was producing all manner of micro
    updrafts in which the gulls were soaring without otherwise moving, some
    of them 'surfing' inches in front of the windshield. These things have
    such a sense for the air that they ride even the wave over a full loader
    bucket but won't even try an empty one. It's almost as if they could
    'see' the air. Image composition is not always an available luxury.
    Everytime I'd stop the magic would fall apart, so I would have had half
    a second to grab a P&S with one hand and just fire it, maybe several
    times, but the sorting out and framing would definitely have had to
    follow :)

    I didn't even try mainly because this dynamic would have to be filmed
    instead of photographed and that is really something I could not do
    under the circumstances.
    bad sector, Jun 5, 2012
  6. bad sector

    bad sector Guest

    I just downloaded the manual and went in for a closer look at so called
    MANUAL focus. There's no sign of numerical distance reference,
    apparently it just allows one to eyeball focus on the monitor. Thus if I
    want to focus at 200 feet I cannot see that number anywhere while
    focusing even manually :-(((

    The depth of field table (or rule of thumb if any) that depends on lens
    opening and focal distance, is that about the same on all cameras/lenses
    or is it specific to every lens

    bad sector, Jun 6, 2012
  7. bad sector

    bad sector Guest

    The latest prices are 600us/750cdn with the 18-55 lens

    I'm not too nostalgic about carrying a bag of stuff either. Just took
    out my old F-401 and cried over the $50's they're getting on ebay, that
    and the POS s1500 might get me $100 total.

    When you talk Nikon zoom lenses though I'm sure you'll agree that
    they're still far better than the p&s allinwonder superzooms :)

    I'd love to buy a coolpix if it gave me some manual authority, in light
    of the last p&s and the headaches it has given me I'm not really
    interested in throwing good money after bad :-(
    bad sector, Jun 6, 2012
  8. bad sector

    Bruce Guest

    Better at what? My partner uses a Panasonic FZ38 (FZ35 in USA) which
    has an 18X zoom lens with an equivalent focal length range of
    27-486mm. There is no zoom Nikkor which approaches that range.

    The zoom Nikkor with the greatest range is the 18-200mm DX which has
    an equivalent focal length range of 27-300mm. So it doesn't cover the
    300-486mm range at all, but the Panasonic does.

    The 18-200mm Nikkor is optically a poor performer. It reviews well
    against other lenses of its type, but they are all pathetic performers
    and the Nikon is only the least worst of a bad bunch. It appeals only
    to lazy people who buy an interchangeable lens camera but cannot
    manage to make the small effort to change lenses. So they buy one
    lens that will "do everything". Alas, it will do everything except
    provide decent results and I would not recommend it to anyone who
    takes any pride in their results.

    It is probably worth looking through the pages of DPReview and in
    particular the specifications of various p&s and superzoom cameras to
    see if there is anything that better fits your needs.
    Bruce, Jun 6, 2012
  9. bad sector

    bad sector Guest

    I wouldn't want to mislead anyone, this is NOT quite accurate!

    On p126 of the sx260 manual there is an "MF Indicator" bar that "shows
    the distance and focal position" (somewhat different wording is used on
    p96 of the sx230 manual). Not sure if I understand this, focus is a
    distance and not a position. Does the manual mean that the bar shows the
    distance marks and the focus distance against them? If so then where's
    the infinity marking or is it one those dynamic scales? Could anyone
    with access to one of these cameras try it out? There's no camera store
    around my home so I can't just go over for some hands-on trial. What I
    want is the ability to set focus by setting a distance in feet up to
    infinity, interpolating as required but NOT by adjusting the 'texture'
    in a focus square/rectangle.

    bad sector, Jun 7, 2012
  10. bad sector

    otter Guest


    You should try the Canon forums above to ask your question, You may
    find someone who actually owns the camera. There used to be a
    superzoom owner who politely offered helpful, informed opinion to the
    DSLR owners here, but he may be in jail now.

    If manual focusing on the sx230 is like other Canon compact cameras,
    you will probably not be terribly happy with it. Seems everyone
    expects the camera to do all of the work these days, and safeguards
    are built in so that the camera reverts to autofocus after each shot.
    At least that was my experience with manual focusing on the G12. But
    maybe I was missing some configuration setting in a menu somewhere. I
    only used the camera for a short while before my wife stole it from me.
    otter, Jun 7, 2012
  11. Let someone with a camera and knowledge ride shotgun.
    Or let someone else drive.
    Problem solved.

    Wolfgang Weisselberg, Jun 7, 2012
  12. That's why Canon rocks and Nikkon sucks. Canon has two 9.3-930mm
    (1860mm with extender) f/1.7-4.7 lenses ...


    Wolfgang Weisselberg, Jun 7, 2012
  13. Why would you want to focus at 200 feet? At that distance
    you have 60 feet DOF at the least with that camera.
    It only depends on the aperture and focal length and on the
    allowed circle of confusion, which again depends on the factor
    between output and sensor size and viewing distance.

    Wolfgang Weisselberg, Jun 7, 2012
  14. bad sector

    bad sector Guest

    Nothing special, I just threw in a number, or maybe I want the subject
    to just fit into the DOF. I should have been clearer about what I want.
    There are two separate actions the first being fucusING (like in the
    viewfinder) and the other SETting-focus where you set a number for the
    distance. Let'say I want to make a 1 minute exposure of a town at night
    in the snow from a water tower (I actually made a postcard that way
    once). Trying to focus in the viewfinder would be an exercise in
    futility but if I know the distance (and I can guess pretty good) then
    that's where setting the focus distance comes in. In this case it was
    infinity but it serves to illustrate one possible need for the number
    bad sector, Jun 7, 2012
  15. If you want to set by number you should carry out some experiments to
    check the accuracy of the number scale with respect to your
    purposes. On some cameras/lenses it's accurate enough, on some it's so
    silly you wonder why they bothered to put the numbers there.
    Chris Malcolm, Jun 8, 2012
  16. bad sector

    bad sector Guest

    THAT I didn't know, thanks for the info
    bad sector, Jun 8, 2012
  17. bad sector

    Joe Kotroczo Guest

    I've been known to carry my G11 in my shirt pocket...

    Yes, it was a baggy pocket.
    Joe Kotroczo, Jun 8, 2012
  18. Well, most cameras in the P&S class have a scene mode exactly
    for landscapes in the dark. Hyperfocal length.

    And since at said 28mm the hyperfocal length is around 2 meters
    for this camera ...

    Wolfgang Weisselberg, Jun 8, 2012
  19. What slows CDAF is not knowing which way to jump when the focus target
    is out of focus. I do a lot of manual focusing because it's more
    accurate, esp with wider angle lenses, and some of my lenses are
    manual only. I've noticed that when looking at a high contrast edge
    which isn't strongly coloured go in and out of focus that the blue and
    red ends of the spectrum shift in different ways. Looks like
    chromatic aberration, but there's none present when it's properly
    focused, only when it goes out of focus. The reddish and greenish
    sides swop sides when passing through the focus point. They merge into
    accurate focus at the focus point.

    Is this a defect present in only some lenses, or is it a natural
    consequence of the way chromatic aberration is corrected in all good
    lenses? I can only see it easily on extreme focus targets, such as a
    bright specular spot, but software should be able to track more subtly
    shifts of colour.

    If so, it might be able to be used to get a directional handle
    on CDAF. If so, then CDAF should be able to track and predict not just
    lateral but distance movement of a moving focus target. But can this
    method be somehow contrived to deliver the resolution of out of focus
    distance given by phase?

    If so, given the processing power and ingenuity/education of the
    programmers they employ, CDAF ought to be able to track and predict
    focus target movement even better than phase.

    (If a team isn't already working on these questions, sounds like a
    good student project in machine vision :)
    Chris Malcolm, Jun 10, 2012
  20. You are overlooking another possibility -- your eyes and brain don't see
    the chromatic aberration as much on a sharp line as on a blurred one.
    I'd have to guess this falls under "too obvious"; if it were that easy,
    they would have been using it for the last 5 years.
    David Dyer-Bennet, Jun 10, 2012
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