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  1. #11

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    Quote Originally Posted by Denis K View Post
    I think an example to demonstrate my point is when taking a picture with the lens nominally focused at infinity. If you simply focus at an object at infinity, as you describe, then you will throw away a great deal of potential depth of field for the comfort of seeing a maximally sharp image (of infinity) in the viewfinder. From the standpoint of your composition this may be what you want, but I doubt it. I can't think of any simple way of boiling down the process of setting the focal plane of an image that does not come to terms with the near and far points of acceptable focus based on your estimate of the depth of field. Even if your strategy involves setting the focal plane at a fixed distance and hoping for the best, this strategy does not work well at infinity. I do, however, agree that this simple strategy will work if your objective is to maximally render a flat plane, such as the tombstone in one of the original posters portfolio pictures.
    I don't describe simply focussing at infinity.
    I strongly feel we have to put focus there where focus must be. Focus is a tool used to set the focus of the image we create.

    'Hyperfocal', considering the near and far limits of focus, is a technical, numerical appraoch, that fails to acknowledge that the image is about something, instead acts your subject as if it is a distance range.

    So we must set focus where it is supposed to be (say, the eye in a portrait - you decide: it can be anything, as long as you decide what the focus of the image you are creating is!), then use the aperture to control how the bit in focus relates to the rest.
    There are limits to what you can do with the aperture. But i don't think that is bad: it protects us against ourselves, should we ever feel the desire to make too much part of the subject of our images, letting it drown in indecision.

    Nowhere in the process should near and far limits play any role. This is not a mathematical thing you are doing. So infinity or not, it does not make a difference. We shouldn't even think in those terms.
    The silliest thing i think you can do, by far (and then some), is to let focus be decided by mathematics. Let the number game, condicence, decide what is and what is not the focus of your image.

    So we do not "hope for the best". We carefully and deliberately place focus, and use the aperture to get the image the way we want it to be.


    Alll the above is, i think, extremely important. Yet beside the point: when you know what to focus on, it can be hard to decide whether you have it, critically, or not.
    Eyesight, as suggested, is a factor.
    Yet in the end, it remains a bit of a guessing game. Like anything that we want to do as good as possible.
    Last edited by Q.G.; 10-05-2009 at 04:28 PM. Click to view previous post history. Reason: spelling - and a minute bit of editing, to clarify.

  2. #12
    Maris's Avatar
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    I think I've had the same experience as the OP and discovered it was the camera's fault!

    A very small amount of backlash, play, or slack in the focussing mechanism seems to cause a "flat" spot in the focussing response...focus, turn, no change, turn some more, out of focus. Very disconcerting.

    My Mamiya RB67 has a variable friction control on the focussing mechanism so if there is a bit of looseness in the focussing rack the fingers won't feel it. Only the eye on the focussing screen notices something wrong.
    Photography, the word itself, invented and defined by its author Sir John.F.W.Herschel, 14 March 1839 at the Royal Society, Somerset House, London. Quote "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..". unquote.

  3. #13
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    My question is about the tiny spot of critical focus where, for me, it is extremely difficult to tell the difference, even with the loupe. I know that for the exact focal length of a technical piece of equipment the is "the" spot where it is perfectly in focus.

    How do you decide when it is focused correctly?

    Critical focus is achieved by "mind over matter".

    If you don't mind, it don't matter.
    f/22 and be there.

  4. #14
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    Quote Originally Posted by stradibarrius View Post
    On my manual focus cameras like my RB67 or Yashica 124G when I get to the "critical focus spot" where it seems to be in focus...a tiny bit more and it is still in focus and then it starts to go OOF again.
    My question is about the tiny spot of critical focus where, for me, it is extremely difficult to tell the difference, even with the loupe. I know that for the exact focal length of a technical piece of equipment the is "the" spot where it is perfectly in focus.

    How do you decide when it is focused correctly?
    This may seem like a silly question...but???
    *****
    We were taught thusly: with the magnifier in place (124G), focus until you see the image "pop" in then go a bit beyond it. Return slowly to the point of focus; a bit beyond, but less than before. Another time or two and you are "locked in". Now, with my six decade old eyes, it is not as easy as it was; but it is still the way I do it.
    John, Mount Vernon, Virginia USA

  5. #15
    stradibarrius's Avatar
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    John I can identify with the old tired eyes..LOL! You just described my method. I get to the "spot" and then go back and forth in smaller steps until I think it is as good as it is going to get.
    I like the idea of mind over matter!!!
    "Generalizations are made because they are generally true"
    Flicker http://www.flickr.com/photos/stradibarrius
    website: http://www.dudleyviolins.com
    Barry
    Monroe, GA

  6. #16
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    Quote Originally Posted by stradibarrius View Post
    John I can identify with the old tired eyes..LOL! You just described my method. I get to the "spot" and then go back and forth in smaller steps until I think it is as good as it is going to get.
    I like the idea of mind over matter!!!
    *******
    Yup. Even with young eyes, that's the way to do it.
    John, Mount Vernon, Virginia USA

  7. #17

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    As someone who shoots mostly street photography (often with an RZ!) I prefer to focus each and every shot. There are any number of reasons why negatives may be out of focus - film not flat (more likely with 120 film then 135) mirror out of alignment, after market focusing screens, etc. My RZ Pro II has a second fine focus knob which I find very useful.

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