Q: Infinity focus being nothing of the sort

Discussion in 'Digital Photography' started by rolandberry, Jul 3, 2006.

  1. rolandberry

    rolandberry Guest

    I have owned a few conpact digital cameras and I have been left with
    the impression that the infinity focus setting is nothing of the sort
    and is more like 30 feet. Has a study been done about this that I could
    link to?
     
    rolandberry, Jul 3, 2006
    #1
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  2. rolandberry

    bugbear Guest

    With "reasonable" DOF, that oughta' do it.

    They may be trying to exploit the "box brownie" effect.

    "Hyperfocal distance" and all that jazz.

    BugBear
     
    bugbear, Jul 3, 2006
    #2
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  3. rolandberry

    Roy G Guest

    Hi.

    Have you just noticed.

    This has been going on for years with P & S cameras, especially at the
    cheaper end. The Autofocus might only have 3 steps, 30, 15 & 8 ft. The 30
    ft setting might well be at the near limit of the lens travel, so that
    actually means only 2 steps. They rely upon the wide DoF with a small focal
    length, and aperture to ensure sharpness.

    The more expensive the Camera the more steps. One of the UK Mags used to
    include the number of steps in their Camera Listings.

    Some of the Film P & S had a drilled plastic plate, which put a larger or
    smaller hole behind the lens according to the ISO selection lever, and only
    had a 1 speed shutter, and I am not just talking about cameras from Eastern
    Europe or with unheard of names.

    The Makers have a pretty low opinion of the average persons knowledge of
    photography, and know that any lack of sharpness at infinity will probably
    never be noticed. How many of the general public ever take pictures of
    anything except people, or objects in the near to middle distance.

    Having worked at reception in a Camera Repairer, I was horrified at what
    most people would accept as a good quality photograph.

    I know that when I sometimes had cause to complain to a Photo Printing Shop,
    ( I nearly said Lab ), the explanations I got were often ludicrous. They
    only try it on with that sort of rubbish, because they know Joe Public does
    not have a clue.

    I can not believe that any of this will have changed, just because most
    people use digital, which is even more technical than film.

    Roy G
     
    Roy G, Jul 3, 2006
    #3
  4. Roy G wrote:
    ...
    And they are right. :)

    It should be noted that the average person posting to this NG is not the
    average person.
     
    Joseph Meehan, Jul 3, 2006
    #4
  5. rolandberry

    Roy G Guest

    True enough Joseph. If you read some of the rubbish which was being spouted
    on "best compact digital tested" on 29th June, you might think there is not
    that much difference. Could it be a little knowledge is worse than none.

    Roy G
     
    Roy G, Jul 3, 2006
    #5
  6. rolandberry

    Ken Burns Guest

    Depending upon the lens's actual focal length, 30 feet might be at or beyond
    infinity for that lens.
     
    Ken Burns, Jul 3, 2006
    #6
  7. Too infinity and beyond!!!

    It would not be dependent on the lens's focal length, but maybe beyond
    its focusing capability. BTW I know of no way 30 feet can ever be beyond
    infinity. :)

    Actually everything you intended does make sense and I think most
    everyone would read it in the way you intended. Which is a good thing for
    me, considering how often I make like errors.
     
    Joseph Meehan, Jul 3, 2006
    #7
  8. rolandberry

    Scott W Guest

    Most of my cameras well focus past infinity and very few have a good
    setting at infinity.
    The one that seems to do the best at setting to infinity is in fact a
    pretty cheap point and shoot.

    Inexpensive zoom lenses on DSLR rarely are going to have one setting
    for infinity that works across the zoom range.
    A fixed focal length lens will have a much better chance, or a high-end
    zoom lens.

    Scott
     
    Scott W, Jul 3, 2006
    #8
  9. rolandberry

    rolandberry Guest

    Jesus wept! Are things that bad now when it comes to knowledge about
    photography?
     
    rolandberry, Jul 4, 2006
    #9
  10. rolandberry

    Ken Burns Guest

    I'm sorry that I don't understand your reply. Could you please explain?
     
    Ken Burns, Jul 4, 2006
    #10
  11. rolandberry

    Ron Hunter Guest

    There is some point in which the focus will go no farther towards the
    long range. This point, depending on the lens setup occurs in the range
    of 30 to 50 feet, and at that point, there is no further lens movement
    from there to infinity. Does that clear up the point?
     
    Ron Hunter, Jul 4, 2006
    #11
  12. Is that the distance marked on the lens, or is it the distance at which
    the lens is actually focusing?
     
    Joseph Meehan, Jul 4, 2006
    #12
  13. rolandberry

    Ken Burns Guest

    It's the distance the lens is actually focussing. The distance markings on
    the lens aren't necessarily very accurate, though, if one pays big bucks for
    a lens, one might expect the markings to be exact.
     
    Ken Burns, Jul 4, 2006
    #13
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