Stops Between Zone III and Zone VII

Discussion in 'Film and Processing' started by jarrod_diermajer, Sep 7, 2017.

  1. Hello, just trying to get some clarification on the zone system.
    I'm under the impression that there is 4 stops between zone III and VII. I've heard some people saying that there are 5 stops, which has now confused me....

    If i meter the scene and the:
    - darkest area is EV 8
    - lightest area is EV 12

    If i place the metering for the darkest area on zone III where will my highlights fall? Zone VI or VII?
  2. Vincent Peri

    Vincent Peri Metairie, LA

    It's 5 stops -

    zone III is the first stop
    zone IV is the 2nd stop
    zone V is the 3rd stop
    zone VI is the 4th stop
    and Zone VII is the 5th stop.


    EV 8 is zone III
    EV 9 is zone IV
    EV 10 is zone V
    EV 11 is zone VI
    EV 12 is zone VII
  3. sweet. cheers for the clarification. I've clearly been counting the steps between zones as stops.
  4. James G. Dainis

    James G. Dainis Moderator

    That is why I put a home made zone scale on my spot meter.

  5. "It's 5 stops -"

    No, it's not!

    "zone III is the first stop" - Agreed, but this counts as zero stops difference.
    "zone IV is the 2nd stop" - but only one stop up from zone 3
    "zone V is the 3rd stop" - two stops up
    "zone VI is the 4th stop" - 3 stops up
    "and Zone VII is the 5th stop." - with 4 stops difference.

    7 take away 3 was only 4 when I went to school.

    That's if you don't apply normal sensitometry rules to Ansel's assertion that zone 5 = a reflectivity of 18%. If so, then that means Zone 8 (described as white with texture) has a reflectivity of 144%; which is plainly nonsensical. Not to mention that texture necessarily implies a variation of reflectivity or density.

    So you can either have zone 5 = 12.5% reflectivity, and all other zones fall (roughly) into place. Or zone 5 = 18%, and there's less than a one stop spacing between zones. Either way; there's a flaw in Ansel's maths or logic.
    Last edited: Sep 8, 2017
  6. Vincent Peri

    Vincent Peri Metairie, LA

    You're misreading the original question. He didn't say anything about differences between the stops. He asked how many stops BETWEEN zone III and zone VII. If that was the original intent, then the correct answer is 3 stops, since only zones IV-VI are BETWEEN III and VII. But I applied some common sense to the problem and reasoned the OP wanted to know how many total stops are represented. It IS 5 stops.
  7. No, because there are zero stops between zone iii and zone iii. You're counting the first zone as one zone difference, which it plainly isn't.

    This is simple arithmetic.

    If you add 5 zones to zone iii, you get zone viii. Not zone vii.

    There are only 4 zones difference between zone iii and zone vii.

    But as I said; it's all moot because it appears that Ansel himself couldn't add up properly. And if plus or minus half a stop exposure makes no odds, then what's the point of getting hung up on the zone system?

    "He didn't say anything about differences between the stops. He asked how many stops BETWEEN zone III and zone VII."

    And how is asking 'how many stops between' different from asking how many stops difference? Pray explain.
    Last edited: Sep 10, 2017
    wogears likes this.
  8. Vincent Peri

    Vincent Peri Metairie, LA

    Again, the OP NEVER mentioned the word DIFFERENCE anywhere. I explained it to you, and my explanation still stands.
  9. Let's make this simple.
    Assuming you're right-handed - write "zone iii" on your left thumb and "zone vii" on your left little finger. Now count the spaces between the digits on your left hand.

    I'll be very surprised if you get past four.

    And notice I didn't yet use the word difference.
    Last edited: Sep 10, 2017
  10. Vincent Peri

    Vincent Peri Metairie, LA

    Like I said earlier, you get 3 digits (stops). You don't count your thumb and left finger, because they're NOT BETWEEN any fingers.

    I'm finished with this.
  11. How about this? If you know the exposure that will place your subject on Zone III and you rather it fell on Zone VII then you must give four stops more exposure.
    denny_rane likes this.
  12. Vincent Peri

    Vincent Peri Metairie, LA

    Yes, four stops additional exposure, but that has NOTHING to do with the original poster's question.
  13. He metered the dark and light areas at 8 and 12 EV. The range is 4 stops. Now, we place the dark area in Zone III. Depending on the calibration of one's Zone System, the light area should end up in Zone VII. Question- is a Zone a range of tones, separated by sharp dividing lines, or is a Zone a specific value on a continuum of tones?

    As for the percent reflectivities, some joker wrote this a long time ago-

    Is an 18% Gray Card Zone V

    Don't know if it helps or hurts.

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