Zone system question

Discussion in 'Exposure Discussion' started by metod, Apr 20, 2006.

  1. metod

    metod Member

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    I’m quite new in using a view camera and was reading a lot about the zone system lately. I think I understand the main principle and advantages of the system (placing values in different shades of grey, compacting and expanding opacity range of the negative at will…..)
    There is the part about choosing an exposure when applying the zone system I thought of asking you. I think the best I would explain my question is by the example…..

    Let’s say I have a sun filled, contrasty scene in front of me. Ideally, I’d like to preserve both shadows and highlights. Pointing meter at both tells me that this is too much for the negative to record properly. I would know that I have to compact the zones, so I would chose to overexpose by 2 stops and give less development to the negative later, right?
    My question is, which exposure time to choose for a scene like this, would it be the shadows placed on zone II plus 2 stops, or an average between shadows and highlights metering, plus 2 stops?
    Knowing this would help me a lot as I’m heading out soon with my camera.

    Thanks.
     
  2. Jorge

    Jorge Inactive

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    You are correct in your assumptions with the exception you would place the shadows in Zone III plus 2 stops.

    If you want to do a more accurate methodology I suggest you give the BTZS (Beyond the zone system) a try, it is a far more powerful method for expusre/development.
     
  3. Donald Miller

    Donald Miller Member

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    In the situation that you described you would increase exposure but not by two stops. The increase would be related to the amount of reduction in development that you would need. For instance if you have one zone more then your materials can depict (N-1)you would increase exposure by 1/3 stop. For N-2 you would increase exposure by 2/3 stop.

    Placing the shadow values is the first determination that you need to make. Most would place their shadows on III or IV for greater luminance (depending on the film used). Zone II has no information other then tonal representation. Shadow values always are the determiner of exposure.
     
  4. kjsphoto

    kjsphoto Subscriber

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    Yes you want to move in full stops to compensate not 1/3 of a stop. You will however in conjunction in moving your speed or aperture in full stops move your film index 1/3 to 2/3 in either direction to compensate for the change for proper shadow detail when you developed your negs. Remember exposure controls shadows and development controls highlights.

    Also you are going to have to test your film and honestly N-2 is a waste of time, just dial your film in for N-1, N, N+1 and N+2. I am a long time zone system user but many do like BTZS for its simplicity and ease of use.

    If you are going to use the ZS you seriously need to dial in your film for N because if you done you have no idea what the actual true speed of the film is and your results and all your N+, N- will just be in vain.

    Good luck,


    Kev
     
  5. bob01721

    bob01721 Member

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    Yup. That's how I always understood it.

    That's where you lost me, Kev. I thought you determine (beforehand) the film index so that a Zone V reading will give a Zone V area on the negative with normal development of that particular film. After that, it's "expose for the shadows and develop for the highlights" since the film index is set. No? Where am I going wrong?
     
  6. kjsphoto

    kjsphoto Subscriber

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    No, you do get your film index first, sorry for the confusion. But you dont test for Zone 5 you test for zone 1 = index and zone 8 = density (highlight area).

    But when you do a N+1 for exampel you speed will also change 1/3 to 2/3 depending on the film so you have to test for that also. On a N+1 you would test for Z1 and Z7 and expand Z7 out to Z8.

    Lets say your normal is EI 200, Z1 = .11 and Z8 = 1.2 over base fog.

    So for N+1 you could have an EI of 250 or 320 Z1 = .11 and Z7 expanded out to Z8 would also read 1.2.

    N+2 could take you EI up to 400. For an N+2 test you expand z6 out to z8.
     
  7. bob01721

    bob01721 Member

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    Oops! Gotcha. Thanks.

    Ah! Now I understand. That's gotta be the most clear, easy-to-understand explanation I've ever heard. Why couldn't St. Ansel be as succinct! Thanks again, Kev!
     
  8. Michel Hardy-Vallée

    Michel Hardy-Vallée Membership Council Council

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    That's an excellent thread and I'm glad I saw it. I was a bit at a loss recently when I was comparing film developped (using XTOL) for different durations. I did Les McLean's procedure to expose the same subject at various EIs and develop at different times. I couldn't understand why for the life of me my shadow details kept changing between dev times. NOW I understand, and I will make my tests more rigorous! Thanks Kevin!
     
  9. df cardwell

    df cardwell Subscriber

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    There are many ways to use the Zone System. That is it's entire reason for existence.

    One convention is that described here: basing the exposure on Zone II or III, and the development upon VII or VIII.

    If one is concerned with Zone V, one exposes for V. The flexibility of the system is what determines it's value. The reason Adams was not more succinct was that he offered a method for accomplishing a more diverse vision than a rote execution of "expose for II, develop for VIII".

    Two things have yet to be mentioned. First, the Premise of the Zone System is to be a coherent and repeatable technique to fulfil the artist's vision, not the other way around.

    Secondly, there is no point in the logical sequence where the camera is disconnected from the film, the film disconnected from the paper, and the paper from the camera. It is not modular, it is a single system.

    Some prefer to develop an intuitive understanding of the way paper works, others are more capable with graphs. Either way, before one begins to judge a scene based upon what the lightmeter says, one needs to know what the paper will say, and what the scene says to you.

    Finally, to answer your specific question, one needs to know your film and developer combination. With some, one would correctly give additional exposure for the shadows and reduce the development for the highlight to fall where you wish them to be.

    For me, and many, the film and developer combination I use lets me expose for the shadows and will hold the highlights with no need for N- development.

    The specific answer depends completely on the materials in use.

    d
     
  10. metod

    metod Member

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    I know this will be a long journey to fine tune the whole system, but I hope an exciting and rewarding one. Thanks all for the input.
     
  11. Christopher Walrath

    Christopher Walrath Member

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    There is another possibility here. Pre Exposure. This is expolsing the negative to a surface of uniform luminousity before making you omage, which can be done with any camera that has a double exposure feature.
    The following exposure zones have the following luminousity factors.
    Zone 0 = 1/2
    Zone I = 1
    Zone II = 2
    Zone III = 4
    Zone IV = 8
    Zone V = 16
    Zone VI = 32
    Zone VII = 64
    Zone VIII = 128
    Zone IX = 256
    Zone X = 512
    If you preexpose a flat surface such as a wall or some other object with little texture and uniform luminosity then meter the surface and expose your negative placing it on Zone II (three stops down from the meter reading as this will be a Zone V/18% gray reading). Then expose your subject with NO ADJUSTMENTS to your exposure meter reading.
    Now Zone II has a luminousity effect of 2. When applied to the scale above, you will see the effect of Pre Exposure.
    Zone 0 = 1/2 +2 + 2 1/2
    Zone I = 1 + 2 = 3
    Zone II = 2 + 2 = 4
    Zone III = 4 + 2 = 6
    Zone IV = 8 + 2 = 10
    Zone V = 16 + 2 = 18
    Zone VI = 32 + 2 = 34
    Zone VII = 64 + 2 = 66
    Zone VIII = 128 + 2 = 130
    Zone IX = 256 + 2 = 258
    Zone X = 512 + 2 = 514
    According to this preexposure of the negative to a uniformly lighted surface that is exposed on exposure zone two will seriously raise the lower values in the negative (Zone I up to almost Zone III, II to III) while not affecting the higher values (zones V-X show little effect). Practice this as another means of control.