Zone System and Sekonic L-558

Discussion in 'Lighting Equipment' started by heather l, Mar 23, 2005.

  1. Hello,

    I just got my new Sekonic L-558, and am trying to learn how to use it
    in relation to the Zone System. (Using it in Ambient mode with the
    spot function.) I'm also reading, and am nearly finished with,
    Adams' book "the negative". (Feels like I'm reading a math book, but
    with more pictures!) So I have a rudimentary understanding of the
    Zone Sys.

    If I'm understanding correctly (and please let me know if I'm not!),
    when I take a reading with the spot meter in Shutter speed or
    Aperture priortiy mode, the value I get back will be placed on Zone
    5. But, in the EV mode, if I take a reading, the value I get back
    tells me what zone that value is placed on? (Assuming that EV and
    Zone numbers are the same thing.)

    Here's a hypothetical situation with fictious numbers: Let's say I'm
    taking pictures of a white church in the country side on a sunny
    day. I meter the church and I get a reading of f/11 125 speed.
    That's zone 5, right? How then do I get the church to be on Zone
    VII? Do I adjust my shutter speed two stops slower to get two zones
    brighter? (And then is it two full stops, or will two 1/3 increment
    stops work?) Now lets pretend that in the EV mode, I get a reading
    of 7. Is it on Zone 7?

    I have another question wich may or may not be related:
    I metered my gray card with the spot meter in EV mode, and get
    readings anywhere from 6 to 8. But, when I turn it to the incident
    mode and take a reading (again, in EV mode) I get a 5. What's going
    on?

    Thank you for any help you can give me. I have a lot to learn!

    ~Heather
     
  2. (Assuming that EV and Zone numbers are the same thing
    They are not.
    At ISO 100, EV O = 1 second exposure at f/1 or 2 seconds at f/1.4, or 4 seconds at f/2, etc. or at ISO 200, EV 0 = 1/2sec @ f/1, etc. Again at ISO 100, EV 1 = 1 second exposure at f/1.4, etc.
    EV scales are useful for directly comparing how bright one thing is to another becasue as you can see an EV difference of 1 = a one stop difference in brightness.
    Placing Zone system values is also an exercise in determining relative luminosity values but differs in that you are determining those values relative to a measured light value in the scene yo uare photographing as opposed to an absolute scale.
    Here's a hypothetical situation with fictious numbers: Let's say I'm taking pictures of a white church in the country side on a sunny day. I meter the church and I get a reading of f/11 125 speed. That's zone 5, right? How then do I get the church to be on Zone VII? Do I adjust my shutter speed two stops slower to get two zones brighter?
    Yes. You want to make it two stops brighter than Zone V so you let in 4 times as much light.
    (And then is it two full stops, or will two 1/3 increment stops work?)
    No that is only .6666x as much light , not 4.0x as much light.
    Now lets pretend that in the EV mode, I get a reading of 7. Is it on Zone 7?
    No. As I pointed out above there is no connection between an EV scale and a Zne System scale. Think of EV values as a different way of stating the shutter speed + Aperture + ISO (media sensitivity) reading. So unless you then opened up two stops you'd get a Zone V exposure. And you'll probably be happier with a Zone VIII value placement to boot.
    One last thing about using a spot meter: to use one accurately you have to place the meter as close to the lens axis as possible.
    I have another question wich may or may not be related: I metered my gray card with the spot meter in EV mode, and get readings anywhere from 6 to 8. But, when I turn it to the incident mode and take a reading (again, in EV mode) I get a 5. What's going on?
    Spot meters measure the amount of light being reflected by an object. incident meters measure the amount of light falling on the surface.
     
  3. ''Now lets pretend that in the EV mode, I get a reading of 7. Is it on Zone 7?''
    No, this doesn't matter, any EV reading you get is a Zone V reading in terms of the Zone System. With EV numbers your meter 'reads' the amount of available light, this amount is expressed in a number, the EV number. This EV number can be turned into a combination of shutter speeds and f/stops.

    This is exactly what any ttl light meter in a camera does, but you as a photographer only get to see the shutter speed and f/stop your camera proposes to you. When you point a camera with ttl metering at a subject, your camera's meter interprets the amount of light it 'sees' in terms of EV values and transfers this value to a set of shutter speeds and f/stops.

    I.E. let's say you take a center-weighted reading of an average urban scene on a bright and sunny summer day (and your camera is loaded with a 100 iso film). Your camera's meter will most problably value this scene at EV 15. At this point your camera starts to think in terms of f/stops and shutter speeds.

    Let's say your camera is in AV mode (aperture value) and you decided that you were gonna use f/16 to get a good depth of field in the scene. Because your camera's meter decided that the EV value for your scene is EV 15, because you decided to use f/16 and a 100 iso film, your camera's meter 'knows' that EV 15 at 100 iso and f/16 gives a shutter speed of 1/125 s. Why does your camera know this? Because it was programmed this way in the factory to the international standard of EV values that says that EV 0 corresponds to a shutter speed of 1s and an aperture of f/1.0 (at 100 iso).

    Now let's say you go back to same place in the evening and take another reading with your meter (you replaced your 100 iso film with a 400 iso film and still want to use f/16). Your meter will not value the scene at EV 15 any more because it has become much darker, maybe it values the scene only at EV 7. Any how, your camera 'knows' that EV 7 with a 400 speed film and f/16 will give a shutter speed of 1/2 sec. Again, it was programmed to 'know' this.

    In the end whatever EV value your meter reads and whatever combination of f/stop and shutter speed it gives, they are all at Zone V in terms of the Zone system to begin with. If you want to expose your scene at Zone VII however, what you have to do is change the f/stop or shutter speed by +2 stops. So if EV 15 with a 100 speed film at f/16 is Zone V (f/16 and 1/125s), Zone VII would be f/16 and 1/30s. I hope this clears things up a bit.

    What you have to remember is that EV values are standards and that any EV number and their coupled shutter speed and f/stop combinations are always at Zone V. So if you always follow your light meter and set your camera to what it proposes, you'll always get Zone V exposures, this is however not always correct. A bright snow scene for example would be at Zone VII or even Zone VIII, otherwise you'll get underexposed gray snow instead of white snow. The trick in photography is to know when and how much you have to compensate exposure from Zone V in order to get the best printable negative.
     
  4. I know I am posting to a long dead thread here but I believe I can shed some
    light on the subject that will be useful to current and future owners of the
    L-558 and other Sekonic meters in the spot/incident combination lineup (L-508,
    L-608, L-758 and Cine/Digital models).
    It is said that the Sekonic spot meters are too complex and, therefore, not
    suited for Zone System work; this is simply not true. I'll explain how to setup
    your Sekonic meter so that you can pin down the correct zone every time AND
    show you how to allow for the use of a filter at the same time, if you so
    desire.
    The Zone System requires the use of a reflected-light meter. Your Sekonic
    meter has an optimally sized 1-degree spot reading area allowing you to choose
    very distinct subject areas for zone placement. You will, therefore, not be
    using the incident metering function or the retractable integrating sphere when
    using the Zone System.
    The key to simple zone placement with the Sekonic meter is using the “Filter
    Compensation” function. To access this option and make it your default choice
    for “ISO 2,” press and hold the “Mode” button while turning the meter power
    “on.” This will display the “Custom Settings” screen. To the left, you will see
    a two-digit number, in this case “01.” This is the custom setting for the “ISO
    2” button on the face of your meter. To the right you will notice a number “0.”
    This is the default factory setting allowing you to enter a second ISO film
    speed so your primary ISO need not be altered when using, for instance, a
    Polaroid instant camera or film-back for exposure testing purposes. We will
    change this number (the larger one on the right) to “1” by pressing the mode
    button. Now turn “off” the meter. After waiting 8 seconds (per Sekonic) power
    up the meter and press (and hold) the “ISO 2” button. You will notice when the
    button is pressed, the ISO 2 symbol appears in the upper-right corner of the
    display followed by the number “0.0.” This is your Filter Compensation setting.
    To adjust this value, simply press and hold the “ISO 2” button and rotate the
    “Jog Wheel” until a negative or positive value appears on the screen. The digit
    to the left of the decimal represents a change in exposure value by a whole f/stop
    while the digit to the right represents a given tenth of an f/stop exposure
    adjustment. To place your subject on the desired zone value, simply make the
    desired adjustment and read the exposure values from the screen below while
    holding the “ISO 2” button. When you release the button, the standard Zone V
    exposure values will reappear.
    For example, when using the exposure settings indicated by a compensation
    value of “-1.5” you are allowing 1 ½ EV (f/stops) MORE light to reach the
    film/sensor than your original reading on “ISO 1.” You have, therefore, “placed”
    the value of your subject on Zone VI ½. It is helpful to make a small card you
    can tape to the battery door of the meter showing what compensation value
    corresponds to which zone.
    Here’s the list of compensation values and their respective zones:
    Zone I = 4.0, Zone II = 3.0, Zone III = 2.0, Zone IV = 1.0, Zone V = 0.0,
    Zone VI = -1.0, Zone VII = -2.0, Zone VIII = -3.0 and Zone IX = -4.0 (and so
    on…)
    Zones 0 through X can be placed in this manner.
    If interest is shown in this thread, I will continue the tutorial with later
    installments.
    Jake Sirevaag, Fairbanks,
    Alaska. 19 August 2011
     
  5. Thank you, Jake, that was very helpful indeed. My second hand L-558 should arrive today, and I will certainly try your instructions. Could you tell me how you would proceed to calibrate the meter (to a camera)? There are many posts on many forums about this already, some complicated and some very simple, but I am beginning to think that simply shooting a series of bracketed frames (with a grey card as target) should allow me to both calibrate and determine the dynamic range of my (Leica X Vario and X2) sensors. Tips and suggestions will be gratefully received!
     

Share This Page