What zone is "medium gray" ?

Discussion in 'Exposure Discussion' started by pierods, Sep 27, 2012.

  1. pierods

    pierods Member

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    Hello,

    I am taking portraits by spot-metering on (white) people's cheeks and NOT giving it +1 stop.

    I thought that by spot metering on something you would get "middle grey", i.e. zone 5.

    Somebody can explain? I am very well confused...
     
  2. benjiboy

    benjiboy Subscriber

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    18% Grey, ie. a Kodak Grey card is Zone V, Caucasian skin is Zone V1 one stop lighter, so you do need to add +1 stop.
     
  3. pierods

    pierods Member

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    Well, ok, I thought the same.

    But my photos show people's faces not grey at all - maybe my dev times are too long?
     
  4. baachitraka

    baachitraka Subscriber

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    Yes, spot-metering the cheek/subject will place the cheek/subject on Zone V(middle gray). But, you must decided where you want to place the subject's value on Zone Scale. You can place Caucasian skin either on Zone VI or Zone VII depends on skin tone.
     
  5. baachitraka

    baachitraka Subscriber

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    Film needs testing before you employ Zone System.
     
  6. baachitraka

    baachitraka Subscriber

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    I would rather incident meter esp., when shooting slides.

    You can do the same for the negs, when you have uniform light.

    If there are hightlights and shadow, then you may need -1 or +1 correction accordingly.
     
  7. markbarendt

    markbarendt Subscriber

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    Yes, medium gray is considered zone V.

    Caucasian skin normally falls in VI-ish.

    (Roman numerals are normally used to denote zones because zones don't always correlate equally to stops.)

    The classic correction/offset when metering Caucasian skin is to increase exposure by 1-stop.

    My caveat is that it depends on the lighting, the skin that you meter from should not be in shadow nor in highlight.

    If you have, or can borrow an incident meter, you can find the classic camera setting that will give you "normal" zone placement, then you can meter various points on the face to find the various zones and variations on the face, on a grey card, or on some other reference point.

    A bright side cheek may read in zone VIII, dark side zone III.

    That variation is simply the nature of the beast when reflective metering is used. (It is also why, when given a choice, I almost always incident meter.)
     
    Last edited by a moderator: Sep 27, 2012
  8. pierods

    pierods Member

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    Sorry Mark,

    but I am really too ignorant:

    if skin is zone 6, and I meter on it (that puts it on zone 5), to go to zone 6, that is 1 MORE stop - why do you say 1 LESS stop?
     
  9. baachitraka

    baachitraka Subscriber

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    Your meter do not know whether it is a white skin or black coal. It sees the world as medium gray. If you spot meter the skin, then you have to decide where you have to place the skin on Zone Scale. This is the same for metering the shadows...

    For white skin, it is recommended to place either on Zone VI or Zone VII and where as Zone III or Zone IV for shadows. It all depends on how you visualize and what you want on the negative.
     
  10. markbarendt

    markbarendt Subscriber

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    Probably because I haven't had enough coffee yet.

    I stand corrected, open up one stop.
     
  11. pierods

    pierods Member

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    But then I go back to my original question - faces in my photos look already in zone 6/7 (and shadows are fully developed).

    Are my dev times too long then?
     
  12. baachitraka

    baachitraka Subscriber

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    Last edited by a moderator: Sep 27, 2012
  13. batwister

    batwister Member

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    You definitely need to test your film, making at least 3 exposures (-1, indicated and +1, preferably of a continuous coloured wall in direct unchanged light) - then you'll know where middle grey really is. One of those 3 exposures of the wall should be middle grey, then you can adjust your exposures accordingly next time you shoot a roll (i.e. a stop below or above indicated). I usually place Caucasian faces on ZVII (+2).
     
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  15. markbarendt

    markbarendt Subscriber

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    Ok, unless you are shooting and viewing slides, this isn't a surprise.

    Negative films have a safety factor built in and one stop under exposed isn't a problem in many instances. The scene brightness range has a lot to do with this too.

    Your printing process may also be dealing with it "automatically".

    To get more specific we are going to need more detail.
     
  16. Monophoto

    Monophoto Member

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    Developing time mainly affects highlights - Zones VIII and above.

    Zone system metering determines the density of the negative. If you place Caucassian skin as Zone V (middle gray), and then make what Fred Picker called a 'perfect print' (a print which is exposed such that the blank film rebate prints as Zone 0) then Caucasian skin would appear to be Zone V. But you can print that same negative making the Zone V areas appear to be Zone VI by simply holding back exposure.

    So I think what you are experiencing is crossover between film exposure and print exposure. You are underexposing your negatives (placing Zone VI subject areas on Zone V), and then compensating for that by printing so that the areas placed as Zone V as if there were Zone VI.
     
  17. pierods

    pierods Member

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    Monophoto: I think the same.

    Am I correct then by saying that by doing this crossover, I lose zones 8+ ?
     
  18. batwister

    batwister Member

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    You won't learn everything about the zone system in a few replies on this thread. Since the topic title is 'What zone is middle grey?' I think you should try to understand this pretty fundamental principal of photography first. When you've properly exposed your negs, perhaps jotted down the brightness range of scene, then worry about development and losing highlights.
     
  19. baachitraka

    baachitraka Subscriber

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    I am afraid that with roll-film you may not employ the complete Zone System since you cannot able to develop shots individually.

    I would rather expose for shadows and develop normally and let highlights fall where ever they are then try to print and see what you can get.
     
  20. markbarendt

    markbarendt Subscriber

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    Short answer is no.

    Long answer:

    Any given paper/paper grade, has a finite range that is typically much shorter (maybe 6 stops) than any negative's range (8-15stops). The difference in their ranges gives us what is commonly referred to as a film latitude.

    So for a straight print, with no burning or dodging, if a face is placed at the same brightness point on the paper, the print detail will remain essentially the same, from a bracketed set of negatives that may run from maybe as much as 2-stops under exposed to as much as 4-stops over. A lot depends on the scene and the film in question, this is a variable, not an absolute.

    This is essentially the principle disposable and toy cameras use. The film's latitude allows the "same" print to be made from a wide variety of camera/negative exposures without losing detail at either end.

    Print highlight and shadow detail are only lost when you exceed the limits of the film.
     
  21. E. von Hoegh

    E. von Hoegh Member

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    Yes indeed. Unless everything is calibrated you're not employing the zone system.
     
  22. Bruce Osgood

    Bruce Osgood Membership Council Council

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    I suggest getting a copy of Adams' The Negative. It's all right their.
     
  23. Dismayed

    Dismayed Member

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    The zone on a negative corresponds with density on the negative. You can always print to a higher or lower tone, but you may end up compressing eiter shadow or highlight detail in the print.
     
  24. Gerald C Koch

    Gerald C Koch Member

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    Have you considered reading a book on the zone system?
     
  25. Poisson Du Jour

    Poisson Du Jour Member

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    Your spot metering should take in the full spectrum of luminance in the subject, not just one (e.g. from cheeks).
    High areas, low areas and then mid-tone areas must be measured, then averaged (spectrals are never spot metered). Incident reading is only useful for directional light.
    From the HI/LO/AVG measurement, add or subtract for additional exposure based on testing, not blind conversation. You can make it easier by placing a grey card in the frame and spot meter from that (baseline spot) if you have any doubts, then adjust +/– the exposure through active experimentation. It is entirely possible to create a beautiful portrait without resorting to the depth and breadth of the Zone System.
     
  26. markbarendt

    markbarendt Subscriber

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    My first time through "The Negative" was both confusing and illuminating. I agree ZS books are helpful and should be read, but they don't necessarily make sense the first time or two through.