Zone Focus

Discussion in 'Street and Documentary' started by herbert_villa, Mar 18, 2004.

  1. Please explain zone focus. I use a rangefinder with a 35mm or 50mm
    lens.
     
  2. With a rangefinder you won't need Zone Focus.
    But....
    without a ragefinder of sorts you have to guess distance and set the lens to that distance. With higher F-Stop and thus bigger DOF you can use the DOF markers on your lens to set the camera to a distance where your subject is in focus.

    I usualy set my Rollei 35 to F8 and 3 meters which gives me reasonable sharp pictures from subjects roughly within 2 to 6 meters distance.

    Have fun

    Volker
     
  3. Beg pardon!!<”With a rangefinder you won't need Zone Focus.”>

    The DoF scale on a rangefinder camera is perhaps the most important feature these
    cameras have.

    Herbert, zone focusing is a North American term used to describe, presetting the
    focusing distance and using the DoF “zone” to maintain acceptable sharpness for you
    chosen subject. The infocus area of the scene can be read from the DoF scale on the
    lens barrel. Assuming your camera is a traditional manual one such as the Leica or
    Voigtlander Bessa etc.

    To get the greatest possible DoF for any aperture setting, turn the lenses focusing
    ring until the infinity symbol is over the engraved mark for that aperture on the
    DoF scale, eg for f5.6 on a 35mm lens gives you a DoF from about 2.5m (8ft) through
    to infinity. Setting the infiniy symbol on the f16 mark will give a DoF from 1.2 meters
    (4
    feet) through to infinity. Therefore, you know the extent of your depth of field before
    the shot is made and there is no need to focus with the RF. A fast and effect way to
    work.

    It takes some practice to acquire the skill to use this technique well, but once
    mastered it is a very effective tool, particularly in classic street type work. It sounds
    more complicated that it actually is. Have a play around and see what you come up
    with.

    Best regards, Craig
     
  4. With your rangfinder you can see when the camera thinks the scene is focused when the images in the viewfinder line up. With zone focus your setting the lens focus point to a distance you judge.

    I use a Yashica ME1 compact (early 80s) that you have to zone focus. It has two scales, a distance scale in metres and feet (which is underneath the lens so you have to turn the camera over to read it) and on the side of the lens you can easy read, it has 4 pictures (icons) that indicate head, half body, full person and mountains! I have it set to fell person (it has a indent there) and wiggle it either way depending on the situation. Use it enough and it gets very intutitive.
     
  5. Zone focusing works very well for quick, candid type shooting. With a zone set for some range of distance, such as 4 to 9 feet, you need only to move to a distance that puts the subject somewhere in that “zone”, which is not too hard to judge visually.
    That zone came right from my 35mm Summicron’s DOF marks. The lens set for f/8, I move the near range of the zone that I want to use (4 feet) to the f/8 DOF mark on the left, and read the outer range of the zone from the f/8 mark on the right. It is important to understand that this zone is based on certain acceptable criteria for “focus”, and in reality, the actual sharpest focus will be where the lens is focused. In the case of the zone above, the actual point of focus is right between 5 and 6 feet, and for the sharpest rendering, hitting that point would be best. Looking at the DOF marks, and choosing various apertures will reveal numerous zones that can be used depending on the subject, light and scene.
    Another trick for this type of shooting is that if true candid shooting is desired you can shoot without raising the camera to the eye. To this end, it is important to know what will be caught on film. This is where the 35mm focal length has a good advantage. There is a simple trick with this lens. The amount of the scene covered by the long side of the negative is equal to the distance from the subject. If you are 6 feet from a subject with the 35mm lens, the long side of the negative will cover 6 feet. If you hold the camera vertical, and shoot from 6 feet, you get a head to foot capture, and with a zone focused lens, you can pull this off without viewing or focusing for true candids that look different than standing back with a telephoto. FWIW… this same trick works with a 24mm lens, except the rule will be for the short side of the negative.
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  6. There’s a great little program for PDA devices called “pCAM”. Does feet and meters at all f-stops for all focal lengths in all formats. It’s definitely worth a look if you’re interested.
     
  7. And another excellent one called DOFMaster LE for the Palm PDA.
     
  8. Just an additional question: does zone focussing work in practice with medium format (6x6, TLR e.g.),or is it a too shallow DOF? At what apertures can it be efficient, based on your experiences? More precisely, in an average daytime street scene and let's say tri-x 400 film in a TLR, what aperture do you use to make (zone)focusing easy and precise, while keeping a handholdable shutter speed?
    I know it's all subjective, that's why i ask persons instead of formulae. Thanks!
     
  9. mike dixon

    mike dixon Moderator

    Yes, it still works with medium format. While you lose a little
    DOF because of longer focal lengths, you gain a little bit of it
    back because the degree of enlargement is typically less.

    Sunny 16 still applies, so with 400-speed film, expect around 1/
    250 at f16 in direct sun, around 1/125 at f11 in overcast or open
    shade.

    I'm terrible at quickly focusing a TLR, so I use zone focusing
    much of the time if I'm using one for street shooting. If subjects
    are 3 or more meters away, I can usually estimate focus
    distance well enough that f5.6 is sufficient to cover my error (with
    75mm lens); at closer distances, I'll use f8 or f11.
     

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